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Derm Dx

What Is This Growth Localized to the Index Finger?

February 2019
cystic lesion

A 16-year-old girl with no past medical history presented with a cystic lesion located on the right index finger (Figure 1). The lesion was asymptomatic and with gradual growth for 1 year. She denied trauma to the finger or prior occurrence of this lesion. Examination revealed a firm, immobile, fleshy pink-to-red nodule overlying the lateral aspect of the right index finger (Figure 2). No central punctum or discharge was noted. The nodule did not extend into the subungal region and had a fibroelastic consistency. Adjacent skin was normal. An in-office 4-mm punch biopsy was performed. 

What is your diagnosis?

Answer on page 2

{{pagebreak}}

cystic lesion

Diagnosis: Giant cell tumor of the tendon sheath

Figure 1. Fleshy, firm mass localized to the distal lateral index finger.

A giant cell tumor of the tendon sheath (GCTTS) is a benign neoplasm occurring most commonly in the hands and involves the synovial membrane of the tendon sheath, joints, and bursa (Figures 1 and 2).1,2 It is the second most common neoplasm in the hand and can also be found in the feet, knees, and spine.1,2 Though this neoplasm is relatively common overall, GCTTS is not frequently reported in dermatologic literature, most likely due to its commonality as well as treatment by hand surgeons.3 These tumors often develop on the volar aspects of fingers and adjacent skin is typically normal.4 GCTTS affects females more than males and typically presents between 30 and 50 years of age.5 GCTTS in the pediatric population is comparatively uncommon, though cases have been reported. A case series performed by Gholve and colleagues showed that GCTTS in pediatric patients behaves similarly to the adult neoplasm and is often solitary within a single digit. A small number of reports have shown multiple lesions in a single digit that were not interconnected.6 

Figure 2. Side view of the index finger tumor.

side view cystic lesion

The pathophysiology of a GCTTS is uncertain. Data from previous studies suggests that the etiology includes an inflammatory process arising from chronic antigenic stimulation, a reactive proliferation developing from the synovial lining of the tendon sheath/joint, or a lesion of monocyte/macrophage origin.5 GCTTS is classically treated with excision but demonstrates up to a 45% recurrence rate.1,7 This case of GCTTS in a 16-year-old patient highlights the importance of recognizing this cutaneous lesion in the pediatric population.

Clinical Presentation

GCTTS—classified as a benign soft tissue tumor—is a painless, slow-growing, well-circumscribed, and encapsulated mass with lobular architecture lined by fibrous bands.1,7 It is a locally invasive proliferative disorder that was first described by Jaffe and colleagues as a slowly progressive mass that occurs in association with villous or nodular overgrowth.2 Morphologic classification of GCTTS is divided into 2 types: nodular type (on hands), and diffuse type (seen on large synovial lined joints including the knees). 

In addition, a previous study by Geweiler and Wilson demonstrated trauma and multifocality as a possible etiology in 50% of cases. This study induced similar lesions with the extra-articular injection of blood in experimental animals.8 

In a case study with 71 patients, Monaghan described the histology of GCTTS that included cell types such as histiocytes, macrophage-mononuclear cells, osteoclast giant cells, and xanthomatous cells with variable Touton-type giant cells and lymphocytes. A higher mitotic rate of these cells was noted in all 71 cases.5 Our patient’s pathology showed giant cells and Touton-type cells admixed with lymphocytes (Figure 3). 

pathology

Figure 3. Pathology consistent with giant cell tumor of tendon sheath

While GCTTS is usually benign, there are reports of malignant GCTTS. It has been described in less than 20 cases. Sistla and colleagues described 1 case in which a recurrent GCTTS transformed into a malignant lesion over the course of 8 years. While this is extremely rare, it is something to be wary of when suspecting and treating a GCTTS.9

Differential Diagnosis

The differential diagnosis of GCTTS includes many tumors of the hand and digits including a glomus tumor, leiomyoma, blue rubber bleb, neuroma, spiradenoma, angiolipoma, digital mucus cyst, or fibroma. The Table provides a brief overview of the various tumors that a dermatologist must consider when evaluating a tumor on the digits.10-17 On histology, GCTTS can mimic other medical conditions and thus a thorough history, physical exam, excision, and histologic exam helps to properly diagnose the lesion and move forward with the proper treatment plan.18

table

Diagnosis and Management

GCTTS diagnosis is made via histology and treatment is through local excision. Approximately 25% of GCTTS are clinically diagnosed prior to surgery. A recurrence rate of up to 45% has been reported, imparting the importance of excision of a GCTTS carefully with magnification equipment.7 Possible risk factors for recurrence of GCTTS were demonstrated by Fotiadis and colleagues and include incomplete excision of the original mass, location at the distal interphalangeal joint of the finger, osseous pressure erosion, high mitotic activity, proximity to arthritic joint, tumors which are gene nm 23 negative, and type II tumors.19 Al-Qattan described a classification system for GCTTS in 2001, grouping the neoplasm into with or without a single pseudocapsule. Type II tumors (not surrounded by 1 pseudocapsule) had a recurrence rate of approximately 40%.20 In 2007, Gholve and colleagues conducted a study of GCTTS in the pediatric population and found that the recurrence rate in a case series of 29 patients was essentially 0%.6, 21 

Our Patient

Following the 4-mm punch biopsy, pathology revealed a GCTTS (Figure 4). The procedure was well tolerated and sutures were removed 2 weeks post-in-office removal. The entire specimen was removed at the time of biopsy and no further management was required. The patient had no evidence of recurrence, and in-office local excision was well tolerated.

excision

Figure 4. View of tumor during excision.

Conclusion

This article describes an unusual case of GCTTS in the index finger of a pediatric patient. GCTTS is a common benign tumor of the tendon sheath that normally presents between the third and fifth decade of life, making this patient a rather infrequent case. The pathogenesis of GCTTS is unknown but may be due to local trauma and the high mitotic rate of cells in the region. The diagnosis and treatment of GCTTS is meticulous excision to prevent recurrence. Further studies are necessary to understand the origin of GCTTS, but this tumor should be included in the differential of all unknown masses of the hand and fingers both in adults and the pediatric population. 

Dr Sheikh is a second-year dermatology resident at Larkin Community Hospital Palm Springs Campus in Hialeah, FL. 

Ms Bowles is a fourth-year medical student at Ohio University Heritage College of Osteopathic Medicine in Athens, OH.

Dr Hall is a third-year orthopedic surgery resident at SSM St. Anthony Bone and Joint Hospital in Oklahoma City, OK.

Dr Glick is a board certified dermatologist and dermatologic surgeon with clinical and academic practices in south Florida; director of the dermatology residency at the Larkin Hospital, Palm Springs Campus and clinical assistant professor of dermatology at the Herbert Wertheim College of Medicine, Miami, FL.

Disclosures: The authors report no relevant financial relationships.

References

1. Lucas DR. Tenosynovial giant cell tumor: Case report and review. Arch Pathol Lab Med. 2012;136(8):901-906. doi:10.5858/arpa.2012-0165-CR

2. Cho JM, Chang JH, Kim SH, Lee KS. Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle. Childs Nerv Syst. 2016;32(1):175-179. doi:10.1007/s00381-015-2820-5

3. Richert B, Andr J. Laterosubungual giant cell tumor of the tendon sheath: An unusual location. J Am Acad Dermatol. 1999;41(2):347-348.

4. Zeinstra JS, Kwee RM, Kavanagh EC, van Hemert WL, Adriaensen ME. Multifocal giant cell tumor of the tendon sheath: Case report and literature review. Skeletal Radiol. 2013;42(3):447-450. doi:10.1007/s00256-012-1552-9

5. Monaghan H. Giant cell tumour of tendon sheath (localised nodular tenosynovitis): Clinicopathological features of 71 cases. J Clin Pathol. 2001;54(5):404-407. 

6. Gholve PA, Hosalkar HS, Kreiger PA, Dormans JP. Giant cell tumor of tendon sheath. J Pediatr Orthop. 2007;27(1):67-74. doi:10.1097/01.bpo.0000242380.95348.8b

7. Hwang JS, Fitzhugh VA, Gibson PD, Didesch J, Ahmed I. Multiple giant cell tumors of tendon sheath found within a single digit of a 9-year-old. Case Rep Orthop. 2016;2016:1834740. doi:10.1155/2016/1834740

8. Gehweiler JA, Wilson JW. Diffuse biarticular pigmented villonodular synovitis. Radiology. 1969;93(4):845-851. doi:10.1148/93.4.845

9. Sistla RJ, Vidyasagar JVS, Afroz T. Malignant pigmented villonodular synovitis-A rare entity. J Orthop Case Rep. 2014;4(4):9-11. doi:10.13107/jocr.2250-0685.214

10. Morey VM, Garg B, Kotwal PP. Glomus tumours of the hand: Review of literature. J Clin Orthop Trauma. 2016;7(4):286-291. doi:10.1016/j.jcot.2016.04.006

11. Boutayeb F, EI Ibrahimi A, Chraibi F, Znati K. Leiomyoma in an index finger: report of case and review of literature. Hand (N Y). 2008;3(3):210-211. doi:10.1007/s11552-008-9084-4

12. Suksamanapun N, Trakarnsanga A, Akaraviputh T. Blue rubber bleb nevus syndrome. Endoscopy. 2011;43(suppl 2):E411-E412. doi:10.1055/s-0030-1257043

13. Rhode CM, Jennings WD. Pacinian corpuscle neuroma of digital nerves. South Med J. 1975;68(1):86-89. 

14. Ohtsuka H, Tezuka K, Kumakiri M, Ohtsuki Y. Multiple eccrine spiradenomas on the hand, forearm and head. Dermatology. 2002;205(4):401-404. doi:10.1159/00006643

15. Weinzweig J, Minniti JG, Aswad BI, Bowen L. Angiolipoma of the finger masquerading as flexor tenosynovitis. Plast Reconstr Surg. 1999;104(4):1052-1053. 

16. Chae JB, Ohn J, Mun J-H. Dermoscopic features of digital mucous cysts: A study of 23 cases. J Dermatol. 2017;44(11):1309-1312. doi:10.1111/1346-8138.13892

17. Wang JP, Rancy SK, Dicarlo EF, Wolfe SW. Recurrent pigmented villonodular synovitis and multifocal giant cell tumor of the tendon sheath: case report. J Hand Surg Am. 2015;40(3):537-541. doi:10.1016/j.jhsa.2014.11.01

18. Smith PS, Pieterse AS, McClure J. Fibroma of tendon sheath. J Clin Pathol. 1982;35(8):842-848. 

19. Fotiadis E, Papadopoulos A, Svarnas T, Akritopoulos P, Sachinis NP, Chalidis BE. Giant cell tumour of tendon sheath of the digits. A systematic review. Hand (N Y). 2011;6(3):244-249. doi:10.1007/s11552-011-9341-9

20. Al-Qattan MM. Giant cell tumours of tendon sheath: Classification and recurrence rate. J Hand Surg Br. 2001;26(1):72-75. doi:10.1054/jhsb.2000.0522

21. Suresh SS, Zaki H. Giant cell tumor of tendon sheath: Case series and review of literature. J Hand Microsurg. 2010;2(2):67-71. doi:10.1007/s12593-9

cystic lesion

A 16-year-old girl with no past medical history presented with a cystic lesion located on the right index finger (Figure 1). The lesion was asymptomatic and with gradual growth for 1 year. She denied trauma to the finger or prior occurrence of this lesion. Examination revealed a firm, immobile, fleshy pink-to-red nodule overlying the lateral aspect of the right index finger (Figure 2). No central punctum or discharge was noted. The nodule did not extend into the subungal region and had a fibroelastic consistency. Adjacent skin was normal. An in-office 4-mm punch biopsy was performed. 

What is your diagnosis?

cystic lesion

Diagnosis: Giant cell tumor of the tendon sheath

Figure 1. Fleshy, firm mass localized to the distal lateral index finger.

A giant cell tumor of the tendon sheath (GCTTS) is a benign neoplasm occurring most commonly in the hands and involves the synovial membrane of the tendon sheath, joints, and bursa (Figures 1 and 2).1,2 It is the second most common neoplasm in the hand and can also be found in the feet, knees, and spine.1,2 Though this neoplasm is relatively common overall, GCTTS is not frequently reported in dermatologic literature, most likely due to its commonality as well as treatment by hand surgeons.3 These tumors often develop on the volar aspects of fingers and adjacent skin is typically normal.4 GCTTS affects females more than males and typically presents between 30 and 50 years of age.5 GCTTS in the pediatric population is comparatively uncommon, though cases have been reported. A case series performed by Gholve and colleagues showed that GCTTS in pediatric patients behaves similarly to the adult neoplasm and is often solitary within a single digit. A small number of reports have shown multiple lesions in a single digit that were not interconnected.6 

Figure 2. Side view of the index finger tumor.

side view cystic lesion

The pathophysiology of a GCTTS is uncertain. Data from previous studies suggests that the etiology includes an inflammatory process arising from chronic antigenic stimulation, a reactive proliferation developing from the synovial lining of the tendon sheath/joint, or a lesion of monocyte/macrophage origin.5 GCTTS is classically treated with excision but demonstrates up to a 45% recurrence rate.1,7 This case of GCTTS in a 16-year-old patient highlights the importance of recognizing this cutaneous lesion in the pediatric population.

Clinical Presentation

GCTTS—classified as a benign soft tissue tumor—is a painless, slow-growing, well-circumscribed, and encapsulated mass with lobular architecture lined by fibrous bands.1,7 It is a locally invasive proliferative disorder that was first described by Jaffe and colleagues as a slowly progressive mass that occurs in association with villous or nodular overgrowth.2 Morphologic classification of GCTTS is divided into 2 types: nodular type (on hands), and diffuse type (seen on large synovial lined joints including the knees). 

In addition, a previous study by Geweiler and Wilson demonstrated trauma and multifocality as a possible etiology in 50% of cases. This study induced similar lesions with the extra-articular injection of blood in experimental animals.8 

In a case study with 71 patients, Monaghan described the histology of GCTTS that included cell types such as histiocytes, macrophage-mononuclear cells, osteoclast giant cells, and xanthomatous cells with variable Touton-type giant cells and lymphocytes. A higher mitotic rate of these cells was noted in all 71 cases.5 Our patient’s pathology showed giant cells and Touton-type cells admixed with lymphocytes (Figure 3). 

pathology

Figure 3. Pathology consistent with giant cell tumor of tendon sheath

While GCTTS is usually benign, there are reports of malignant GCTTS. It has been described in less than 20 cases. Sistla and colleagues described 1 case in which a recurrent GCTTS transformed into a malignant lesion over the course of 8 years. While this is extremely rare, it is something to be wary of when suspecting and treating a GCTTS.9

Differential Diagnosis

The differential diagnosis of GCTTS includes many tumors of the hand and digits including a glomus tumor, leiomyoma, blue rubber bleb, neuroma, spiradenoma, angiolipoma, digital mucus cyst, or fibroma. The Table provides a brief overview of the various tumors that a dermatologist must consider when evaluating a tumor on the digits.10-17 On histology, GCTTS can mimic other medical conditions and thus a thorough history, physical exam, excision, and histologic exam helps to properly diagnose the lesion and move forward with the proper treatment plan.18

table

Diagnosis and Management

GCTTS diagnosis is made via histology and treatment is through local excision. Approximately 25% of GCTTS are clinically diagnosed prior to surgery. A recurrence rate of up to 45% has been reported, imparting the importance of excision of a GCTTS carefully with magnification equipment.7 Possible risk factors for recurrence of GCTTS were demonstrated by Fotiadis and colleagues and include incomplete excision of the original mass, location at the distal interphalangeal joint of the finger, osseous pressure erosion, high mitotic activity, proximity to arthritic joint, tumors which are gene nm 23 negative, and type II tumors.19 Al-Qattan described a classification system for GCTTS in 2001, grouping the neoplasm into with or without a single pseudocapsule. Type II tumors (not surrounded by 1 pseudocapsule) had a recurrence rate of approximately 40%.20 In 2007, Gholve and colleagues conducted a study of GCTTS in the pediatric population and found that the recurrence rate in a case series of 29 patients was essentially 0%.6, 21 

Our Patient

Following the 4-mm punch biopsy, pathology revealed a GCTTS (Figure 4). The procedure was well tolerated and sutures were removed 2 weeks post-in-office removal. The entire specimen was removed at the time of biopsy and no further management was required. The patient had no evidence of recurrence, and in-office local excision was well tolerated.

excision

Figure 4. View of tumor during excision.

Conclusion

This article describes an unusual case of GCTTS in the index finger of a pediatric patient. GCTTS is a common benign tumor of the tendon sheath that normally presents between the third and fifth decade of life, making this patient a rather infrequent case. The pathogenesis of GCTTS is unknown but may be due to local trauma and the high mitotic rate of cells in the region. The diagnosis and treatment of GCTTS is meticulous excision to prevent recurrence. Further studies are necessary to understand the origin of GCTTS, but this tumor should be included in the differential of all unknown masses of the hand and fingers both in adults and the pediatric population. 

Dr Sheikh is a second-year dermatology resident at Larkin Community Hospital Palm Springs Campus in Hialeah, FL. 

Ms Bowles is a fourth-year medical student at Ohio University Heritage College of Osteopathic Medicine in Athens, OH.

Dr Hall is a third-year orthopedic surgery resident at SSM St. Anthony Bone and Joint Hospital in Oklahoma City, OK.

Dr Glick is a board certified dermatologist and dermatologic surgeon with clinical and academic practices in south Florida; director of the dermatology residency at the Larkin Hospital, Palm Springs Campus and clinical assistant professor of dermatology at the Herbert Wertheim College of Medicine, Miami, FL.

Disclosures: The authors report no relevant financial relationships.

References

1. Lucas DR. Tenosynovial giant cell tumor: Case report and review. Arch Pathol Lab Med. 2012;136(8):901-906. doi:10.5858/arpa.2012-0165-CR

2. Cho JM, Chang JH, Kim SH, Lee KS. Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle. Childs Nerv Syst. 2016;32(1):175-179. doi:10.1007/s00381-015-2820-5

3. Richert B, Andr J. Laterosubungual giant cell tumor of the tendon sheath: An unusual location. J Am Acad Dermatol. 1999;41(2):347-348.

4. Zeinstra JS, Kwee RM, Kavanagh EC, van Hemert WL, Adriaensen ME. Multifocal giant cell tumor of the tendon sheath: Case report and literature review. Skeletal Radiol. 2013;42(3):447-450. doi:10.1007/s00256-012-1552-9

5. Monaghan H. Giant cell tumour of tendon sheath (localised nodular tenosynovitis): Clinicopathological features of 71 cases. J Clin Pathol. 2001;54(5):404-407. 

6. Gholve PA, Hosalkar HS, Kreiger PA, Dormans JP. Giant cell tumor of tendon sheath. J Pediatr Orthop. 2007;27(1):67-74. doi:10.1097/01.bpo.0000242380.95348.8b

7. Hwang JS, Fitzhugh VA, Gibson PD, Didesch J, Ahmed I. Multiple giant cell tumors of tendon sheath found within a single digit of a 9-year-old. Case Rep Orthop. 2016;2016:1834740. doi:10.1155/2016/1834740

8. Gehweiler JA, Wilson JW. Diffuse biarticular pigmented villonodular synovitis. Radiology. 1969;93(4):845-851. doi:10.1148/93.4.845

9. Sistla RJ, Vidyasagar JVS, Afroz T. Malignant pigmented villonodular synovitis-A rare entity. J Orthop Case Rep. 2014;4(4):9-11. doi:10.13107/jocr.2250-0685.214

10. Morey VM, Garg B, Kotwal PP. Glomus tumours of the hand: Review of literature. J Clin Orthop Trauma. 2016;7(4):286-291. doi:10.1016/j.jcot.2016.04.006

11. Boutayeb F, EI Ibrahimi A, Chraibi F, Znati K. Leiomyoma in an index finger: report of case and review of literature. Hand (N Y). 2008;3(3):210-211. doi:10.1007/s11552-008-9084-4

12. Suksamanapun N, Trakarnsanga A, Akaraviputh T. Blue rubber bleb nevus syndrome. Endoscopy. 2011;43(suppl 2):E411-E412. doi:10.1055/s-0030-1257043

13. Rhode CM, Jennings WD. Pacinian corpuscle neuroma of digital nerves. South Med J. 1975;68(1):86-89. 

14. Ohtsuka H, Tezuka K, Kumakiri M, Ohtsuki Y. Multiple eccrine spiradenomas on the hand, forearm and head. Dermatology. 2002;205(4):401-404. doi:10.1159/00006643

15. Weinzweig J, Minniti JG, Aswad BI, Bowen L. Angiolipoma of the finger masquerading as flexor tenosynovitis. Plast Reconstr Surg. 1999;104(4):1052-1053. 

16. Chae JB, Ohn J, Mun J-H. Dermoscopic features of digital mucous cysts: A study of 23 cases. J Dermatol. 2017;44(11):1309-1312. doi:10.1111/1346-8138.13892

17. Wang JP, Rancy SK, Dicarlo EF, Wolfe SW. Recurrent pigmented villonodular synovitis and multifocal giant cell tumor of the tendon sheath: case report. J Hand Surg Am. 2015;40(3):537-541. doi:10.1016/j.jhsa.2014.11.01

18. Smith PS, Pieterse AS, McClure J. Fibroma of tendon sheath. J Clin Pathol. 1982;35(8):842-848. 

19. Fotiadis E, Papadopoulos A, Svarnas T, Akritopoulos P, Sachinis NP, Chalidis BE. Giant cell tumour of tendon sheath of the digits. A systematic review. Hand (N Y). 2011;6(3):244-249. doi:10.1007/s11552-011-9341-9

20. Al-Qattan MM. Giant cell tumours of tendon sheath: Classification and recurrence rate. J Hand Surg Br. 2001;26(1):72-75. doi:10.1054/jhsb.2000.0522

21. Suresh SS, Zaki H. Giant cell tumor of tendon sheath: Case series and review of literature. J Hand Microsurg. 2010;2(2):67-71. doi:10.1007/s12593-9

cystic lesion

A 16-year-old girl with no past medical history presented with a cystic lesion located on the right index finger (Figure 1). The lesion was asymptomatic and with gradual growth for 1 year. She denied trauma to the finger or prior occurrence of this lesion. Examination revealed a firm, immobile, fleshy pink-to-red nodule overlying the lateral aspect of the right index finger (Figure 2). No central punctum or discharge was noted. The nodule did not extend into the subungal region and had a fibroelastic consistency. Adjacent skin was normal. An in-office 4-mm punch biopsy was performed. 

What is your diagnosis?

,
cystic lesion

A 16-year-old girl with no past medical history presented with a cystic lesion located on the right index finger (Figure 1). The lesion was asymptomatic and with gradual growth for 1 year. She denied trauma to the finger or prior occurrence of this lesion. Examination revealed a firm, immobile, fleshy pink-to-red nodule overlying the lateral aspect of the right index finger (Figure 2). No central punctum or discharge was noted. The nodule did not extend into the subungal region and had a fibroelastic consistency. Adjacent skin was normal. An in-office 4-mm punch biopsy was performed. 

What is your diagnosis?

Answer on page 2

{{pagebreak}}

cystic lesion

Diagnosis: Giant cell tumor of the tendon sheath

Figure 1. Fleshy, firm mass localized to the distal lateral index finger.

A giant cell tumor of the tendon sheath (GCTTS) is a benign neoplasm occurring most commonly in the hands and involves the synovial membrane of the tendon sheath, joints, and bursa (Figures 1 and 2).1,2 It is the second most common neoplasm in the hand and can also be found in the feet, knees, and spine.1,2 Though this neoplasm is relatively common overall, GCTTS is not frequently reported in dermatologic literature, most likely due to its commonality as well as treatment by hand surgeons.3 These tumors often develop on the volar aspects of fingers and adjacent skin is typically normal.4 GCTTS affects females more than males and typically presents between 30 and 50 years of age.5 GCTTS in the pediatric population is comparatively uncommon, though cases have been reported. A case series performed by Gholve and colleagues showed that GCTTS in pediatric patients behaves similarly to the adult neoplasm and is often solitary within a single digit. A small number of reports have shown multiple lesions in a single digit that were not interconnected.6 

Figure 2. Side view of the index finger tumor.

side view cystic lesion

The pathophysiology of a GCTTS is uncertain. Data from previous studies suggests that the etiology includes an inflammatory process arising from chronic antigenic stimulation, a reactive proliferation developing from the synovial lining of the tendon sheath/joint, or a lesion of monocyte/macrophage origin.5 GCTTS is classically treated with excision but demonstrates up to a 45% recurrence rate.1,7 This case of GCTTS in a 16-year-old patient highlights the importance of recognizing this cutaneous lesion in the pediatric population.

Clinical Presentation

GCTTS—classified as a benign soft tissue tumor—is a painless, slow-growing, well-circumscribed, and encapsulated mass with lobular architecture lined by fibrous bands.1,7 It is a locally invasive proliferative disorder that was first described by Jaffe and colleagues as a slowly progressive mass that occurs in association with villous or nodular overgrowth.2 Morphologic classification of GCTTS is divided into 2 types: nodular type (on hands), and diffuse type (seen on large synovial lined joints including the knees). 

In addition, a previous study by Geweiler and Wilson demonstrated trauma and multifocality as a possible etiology in 50% of cases. This study induced similar lesions with the extra-articular injection of blood in experimental animals.8 

In a case study with 71 patients, Monaghan described the histology of GCTTS that included cell types such as histiocytes, macrophage-mononuclear cells, osteoclast giant cells, and xanthomatous cells with variable Touton-type giant cells and lymphocytes. A higher mitotic rate of these cells was noted in all 71 cases.5 Our patient’s pathology showed giant cells and Touton-type cells admixed with lymphocytes (Figure 3). 

pathology

Figure 3. Pathology consistent with giant cell tumor of tendon sheath

While GCTTS is usually benign, there are reports of malignant GCTTS. It has been described in less than 20 cases. Sistla and colleagues described 1 case in which a recurrent GCTTS transformed into a malignant lesion over the course of 8 years. While this is extremely rare, it is something to be wary of when suspecting and treating a GCTTS.9

Differential Diagnosis

The differential diagnosis of GCTTS includes many tumors of the hand and digits including a glomus tumor, leiomyoma, blue rubber bleb, neuroma, spiradenoma, angiolipoma, digital mucus cyst, or fibroma. The Table provides a brief overview of the various tumors that a dermatologist must consider when evaluating a tumor on the digits.10-17 On histology, GCTTS can mimic other medical conditions and thus a thorough history, physical exam, excision, and histologic exam helps to properly diagnose the lesion and move forward with the proper treatment plan.18

table

Diagnosis and Management

GCTTS diagnosis is made via histology and treatment is through local excision. Approximately 25% of GCTTS are clinically diagnosed prior to surgery. A recurrence rate of up to 45% has been reported, imparting the importance of excision of a GCTTS carefully with magnification equipment.7 Possible risk factors for recurrence of GCTTS were demonstrated by Fotiadis and colleagues and include incomplete excision of the original mass, location at the distal interphalangeal joint of the finger, osseous pressure erosion, high mitotic activity, proximity to arthritic joint, tumors which are gene nm 23 negative, and type II tumors.19 Al-Qattan described a classification system for GCTTS in 2001, grouping the neoplasm into with or without a single pseudocapsule. Type II tumors (not surrounded by 1 pseudocapsule) had a recurrence rate of approximately 40%.20 In 2007, Gholve and colleagues conducted a study of GCTTS in the pediatric population and found that the recurrence rate in a case series of 29 patients was essentially 0%.6, 21 

Our Patient

Following the 4-mm punch biopsy, pathology revealed a GCTTS (Figure 4). The procedure was well tolerated and sutures were removed 2 weeks post-in-office removal. The entire specimen was removed at the time of biopsy and no further management was required. The patient had no evidence of recurrence, and in-office local excision was well tolerated.

excision

Figure 4. View of tumor during excision.

Conclusion

This article describes an unusual case of GCTTS in the index finger of a pediatric patient. GCTTS is a common benign tumor of the tendon sheath that normally presents between the third and fifth decade of life, making this patient a rather infrequent case. The pathogenesis of GCTTS is unknown but may be due to local trauma and the high mitotic rate of cells in the region. The diagnosis and treatment of GCTTS is meticulous excision to prevent recurrence. Further studies are necessary to understand the origin of GCTTS, but this tumor should be included in the differential of all unknown masses of the hand and fingers both in adults and the pediatric population. 

Dr Sheikh is a second-year dermatology resident at Larkin Community Hospital Palm Springs Campus in Hialeah, FL. 

Ms Bowles is a fourth-year medical student at Ohio University Heritage College of Osteopathic Medicine in Athens, OH.

Dr Hall is a third-year orthopedic surgery resident at SSM St. Anthony Bone and Joint Hospital in Oklahoma City, OK.

Dr Glick is a board certified dermatologist and dermatologic surgeon with clinical and academic practices in south Florida; director of the dermatology residency at the Larkin Hospital, Palm Springs Campus and clinical assistant professor of dermatology at the Herbert Wertheim College of Medicine, Miami, FL.

Disclosures: The authors report no relevant financial relationships.

References

1. Lucas DR. Tenosynovial giant cell tumor: Case report and review. Arch Pathol Lab Med. 2012;136(8):901-906. doi:10.5858/arpa.2012-0165-CR

2. Cho JM, Chang JH, Kim SH, Lee KS. Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle. Childs Nerv Syst. 2016;32(1):175-179. doi:10.1007/s00381-015-2820-5

3. Richert B, Andr J. Laterosubungual giant cell tumor of the tendon sheath: An unusual location. J Am Acad Dermatol. 1999;41(2):347-348.

4. Zeinstra JS, Kwee RM, Kavanagh EC, van Hemert WL, Adriaensen ME. Multifocal giant cell tumor of the tendon sheath: Case report and literature review. Skeletal Radiol. 2013;42(3):447-450. doi:10.1007/s00256-012-1552-9

5. Monaghan H. Giant cell tumour of tendon sheath (localised nodular tenosynovitis): Clinicopathological features of 71 cases. J Clin Pathol. 2001;54(5):404-407. 

6. Gholve PA, Hosalkar HS, Kreiger PA, Dormans JP. Giant cell tumor of tendon sheath. J Pediatr Orthop. 2007;27(1):67-74. doi:10.1097/01.bpo.0000242380.95348.8b

7. Hwang JS, Fitzhugh VA, Gibson PD, Didesch J, Ahmed I. Multiple giant cell tumors of tendon sheath found within a single digit of a 9-year-old. Case Rep Orthop. 2016;2016:1834740. doi:10.1155/2016/1834740

8. Gehweiler JA, Wilson JW. Diffuse biarticular pigmented villonodular synovitis. Radiology. 1969;93(4):845-851. doi:10.1148/93.4.845

9. Sistla RJ, Vidyasagar JVS, Afroz T. Malignant pigmented villonodular synovitis-A rare entity. J Orthop Case Rep. 2014;4(4):9-11. doi:10.13107/jocr.2250-0685.214

10. Morey VM, Garg B, Kotwal PP. Glomus tumours of the hand: Review of literature. J Clin Orthop Trauma. 2016;7(4):286-291. doi:10.1016/j.jcot.2016.04.006

11. Boutayeb F, EI Ibrahimi A, Chraibi F, Znati K. Leiomyoma in an index finger: report of case and review of literature. Hand (N Y). 2008;3(3):210-211. doi:10.1007/s11552-008-9084-4

12. Suksamanapun N, Trakarnsanga A, Akaraviputh T. Blue rubber bleb nevus syndrome. Endoscopy. 2011;43(suppl 2):E411-E412. doi:10.1055/s-0030-1257043

13. Rhode CM, Jennings WD. Pacinian corpuscle neuroma of digital nerves. South Med J. 1975;68(1):86-89. 

14. Ohtsuka H, Tezuka K, Kumakiri M, Ohtsuki Y. Multiple eccrine spiradenomas on the hand, forearm and head. Dermatology. 2002;205(4):401-404. doi:10.1159/00006643

15. Weinzweig J, Minniti JG, Aswad BI, Bowen L. Angiolipoma of the finger masquerading as flexor tenosynovitis. Plast Reconstr Surg. 1999;104(4):1052-1053. 

16. Chae JB, Ohn J, Mun J-H. Dermoscopic features of digital mucous cysts: A study of 23 cases. J Dermatol. 2017;44(11):1309-1312. doi:10.1111/1346-8138.13892

17. Wang JP, Rancy SK, Dicarlo EF, Wolfe SW. Recurrent pigmented villonodular synovitis and multifocal giant cell tumor of the tendon sheath: case report. J Hand Surg Am. 2015;40(3):537-541. doi:10.1016/j.jhsa.2014.11.01

18. Smith PS, Pieterse AS, McClure J. Fibroma of tendon sheath. J Clin Pathol. 1982;35(8):842-848. 

19. Fotiadis E, Papadopoulos A, Svarnas T, Akritopoulos P, Sachinis NP, Chalidis BE. Giant cell tumour of tendon sheath of the digits. A systematic review. Hand (N Y). 2011;6(3):244-249. doi:10.1007/s11552-011-9341-9

20. Al-Qattan MM. Giant cell tumours of tendon sheath: Classification and recurrence rate. J Hand Surg Br. 2001;26(1):72-75. doi:10.1054/jhsb.2000.0522

21. Suresh SS, Zaki H. Giant cell tumor of tendon sheath: Case series and review of literature. J Hand Microsurg. 2010;2(2):67-71. doi:10.1007/s12593-9

cystic lesion

A 16-year-old girl with no past medical history presented with a cystic lesion located on the right index finger (Figure 1). The lesion was asymptomatic and with gradual growth for 1 year. She denied trauma to the finger or prior occurrence of this lesion. Examination revealed a firm, immobile, fleshy pink-to-red nodule overlying the lateral aspect of the right index finger (Figure 2). No central punctum or discharge was noted. The nodule did not extend into the subungal region and had a fibroelastic consistency. Adjacent skin was normal. An in-office 4-mm punch biopsy was performed. 

What is your diagnosis?

cystic lesion

Diagnosis: Giant cell tumor of the tendon sheath

Figure 1. Fleshy, firm mass localized to the distal lateral index finger.

A giant cell tumor of the tendon sheath (GCTTS) is a benign neoplasm occurring most commonly in the hands and involves the synovial membrane of the tendon sheath, joints, and bursa (Figures 1 and 2).1,2 It is the second most common neoplasm in the hand and can also be found in the feet, knees, and spine.1,2 Though this neoplasm is relatively common overall, GCTTS is not frequently reported in dermatologic literature, most likely due to its commonality as well as treatment by hand surgeons.3 These tumors often develop on the volar aspects of fingers and adjacent skin is typically normal.4 GCTTS affects females more than males and typically presents between 30 and 50 years of age.5 GCTTS in the pediatric population is comparatively uncommon, though cases have been reported. A case series performed by Gholve and colleagues showed that GCTTS in pediatric patients behaves similarly to the adult neoplasm and is often solitary within a single digit. A small number of reports have shown multiple lesions in a single digit that were not interconnected.6 

Figure 2. Side view of the index finger tumor.

side view cystic lesion

The pathophysiology of a GCTTS is uncertain. Data from previous studies suggests that the etiology includes an inflammatory process arising from chronic antigenic stimulation, a reactive proliferation developing from the synovial lining of the tendon sheath/joint, or a lesion of monocyte/macrophage origin.5 GCTTS is classically treated with excision but demonstrates up to a 45% recurrence rate.1,7 This case of GCTTS in a 16-year-old patient highlights the importance of recognizing this cutaneous lesion in the pediatric population.

Clinical Presentation

GCTTS—classified as a benign soft tissue tumor—is a painless, slow-growing, well-circumscribed, and encapsulated mass with lobular architecture lined by fibrous bands.1,7 It is a locally invasive proliferative disorder that was first described by Jaffe and colleagues as a slowly progressive mass that occurs in association with villous or nodular overgrowth.2 Morphologic classification of GCTTS is divided into 2 types: nodular type (on hands), and diffuse type (seen on large synovial lined joints including the knees). 

In addition, a previous study by Geweiler and Wilson demonstrated trauma and multifocality as a possible etiology in 50% of cases. This study induced similar lesions with the extra-articular injection of blood in experimental animals.8 

In a case study with 71 patients, Monaghan described the histology of GCTTS that included cell types such as histiocytes, macrophage-mononuclear cells, osteoclast giant cells, and xanthomatous cells with variable Touton-type giant cells and lymphocytes. A higher mitotic rate of these cells was noted in all 71 cases.5 Our patient’s pathology showed giant cells and Touton-type cells admixed with lymphocytes (Figure 3). 

pathology

Figure 3. Pathology consistent with giant cell tumor of tendon sheath

While GCTTS is usually benign, there are reports of malignant GCTTS. It has been described in less than 20 cases. Sistla and colleagues described 1 case in which a recurrent GCTTS transformed into a malignant lesion over the course of 8 years. While this is extremely rare, it is something to be wary of when suspecting and treating a GCTTS.9

Differential Diagnosis

The differential diagnosis of GCTTS includes many tumors of the hand and digits including a glomus tumor, leiomyoma, blue rubber bleb, neuroma, spiradenoma, angiolipoma, digital mucus cyst, or fibroma. The Table provides a brief overview of the various tumors that a dermatologist must consider when evaluating a tumor on the digits.10-17 On histology, GCTTS can mimic other medical conditions and thus a thorough history, physical exam, excision, and histologic exam helps to properly diagnose the lesion and move forward with the proper treatment plan.18

table

Diagnosis and Management

GCTTS diagnosis is made via histology and treatment is through local excision. Approximately 25% of GCTTS are clinically diagnosed prior to surgery. A recurrence rate of up to 45% has been reported, imparting the importance of excision of a GCTTS carefully with magnification equipment.7 Possible risk factors for recurrence of GCTTS were demonstrated by Fotiadis and colleagues and include incomplete excision of the original mass, location at the distal interphalangeal joint of the finger, osseous pressure erosion, high mitotic activity, proximity to arthritic joint, tumors which are gene nm 23 negative, and type II tumors.19 Al-Qattan described a classification system for GCTTS in 2001, grouping the neoplasm into with or without a single pseudocapsule. Type II tumors (not surrounded by 1 pseudocapsule) had a recurrence rate of approximately 40%.20 In 2007, Gholve and colleagues conducted a study of GCTTS in the pediatric population and found that the recurrence rate in a case series of 29 patients was essentially 0%.6, 21 

Our Patient

Following the 4-mm punch biopsy, pathology revealed a GCTTS (Figure 4). The procedure was well tolerated and sutures were removed 2 weeks post-in-office removal. The entire specimen was removed at the time of biopsy and no further management was required. The patient had no evidence of recurrence, and in-office local excision was well tolerated.

excision

Figure 4. View of tumor during excision.

Conclusion

This article describes an unusual case of GCTTS in the index finger of a pediatric patient. GCTTS is a common benign tumor of the tendon sheath that normally presents between the third and fifth decade of life, making this patient a rather infrequent case. The pathogenesis of GCTTS is unknown but may be due to local trauma and the high mitotic rate of cells in the region. The diagnosis and treatment of GCTTS is meticulous excision to prevent recurrence. Further studies are necessary to understand the origin of GCTTS, but this tumor should be included in the differential of all unknown masses of the hand and fingers both in adults and the pediatric population. 

Dr Sheikh is a second-year dermatology resident at Larkin Community Hospital Palm Springs Campus in Hialeah, FL. 

Ms Bowles is a fourth-year medical student at Ohio University Heritage College of Osteopathic Medicine in Athens, OH.

Dr Hall is a third-year orthopedic surgery resident at SSM St. Anthony Bone and Joint Hospital in Oklahoma City, OK.

Dr Glick is a board certified dermatologist and dermatologic surgeon with clinical and academic practices in south Florida; director of the dermatology residency at the Larkin Hospital, Palm Springs Campus and clinical assistant professor of dermatology at the Herbert Wertheim College of Medicine, Miami, FL.

Disclosures: The authors report no relevant financial relationships.

References

1. Lucas DR. Tenosynovial giant cell tumor: Case report and review. Arch Pathol Lab Med. 2012;136(8):901-906. doi:10.5858/arpa.2012-0165-CR

2. Cho JM, Chang JH, Kim SH, Lee KS. Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle. Childs Nerv Syst. 2016;32(1):175-179. doi:10.1007/s00381-015-2820-5

3. Richert B, Andr J. Laterosubungual giant cell tumor of the tendon sheath: An unusual location. J Am Acad Dermatol. 1999;41(2):347-348.

4. Zeinstra JS, Kwee RM, Kavanagh EC, van Hemert WL, Adriaensen ME. Multifocal giant cell tumor of the tendon sheath: Case report and literature review. Skeletal Radiol. 2013;42(3):447-450. doi:10.1007/s00256-012-1552-9

5. Monaghan H. Giant cell tumour of tendon sheath (localised nodular tenosynovitis): Clinicopathological features of 71 cases. J Clin Pathol. 2001;54(5):404-407. 

6. Gholve PA, Hosalkar HS, Kreiger PA, Dormans JP. Giant cell tumor of tendon sheath. J Pediatr Orthop. 2007;27(1):67-74. doi:10.1097/01.bpo.0000242380.95348.8b

7. Hwang JS, Fitzhugh VA, Gibson PD, Didesch J, Ahmed I. Multiple giant cell tumors of tendon sheath found within a single digit of a 9-year-old. Case Rep Orthop. 2016;2016:1834740. doi:10.1155/2016/1834740

8. Gehweiler JA, Wilson JW. Diffuse biarticular pigmented villonodular synovitis. Radiology. 1969;93(4):845-851. doi:10.1148/93.4.845

9. Sistla RJ, Vidyasagar JVS, Afroz T. Malignant pigmented villonodular synovitis-A rare entity. J Orthop Case Rep. 2014;4(4):9-11. doi:10.13107/jocr.2250-0685.214

10. Morey VM, Garg B, Kotwal PP. Glomus tumours of the hand: Review of literature. J Clin Orthop Trauma. 2016;7(4):286-291. doi:10.1016/j.jcot.2016.04.006

11. Boutayeb F, EI Ibrahimi A, Chraibi F, Znati K. Leiomyoma in an index finger: report of case and review of literature. Hand (N Y). 2008;3(3):210-211. doi:10.1007/s11552-008-9084-4

12. Suksamanapun N, Trakarnsanga A, Akaraviputh T. Blue rubber bleb nevus syndrome. Endoscopy. 2011;43(suppl 2):E411-E412. doi:10.1055/s-0030-1257043

13. Rhode CM, Jennings WD. Pacinian corpuscle neuroma of digital nerves. South Med J. 1975;68(1):86-89. 

14. Ohtsuka H, Tezuka K, Kumakiri M, Ohtsuki Y. Multiple eccrine spiradenomas on the hand, forearm and head. Dermatology. 2002;205(4):401-404. doi:10.1159/00006643

15. Weinzweig J, Minniti JG, Aswad BI, Bowen L. Angiolipoma of the finger masquerading as flexor tenosynovitis. Plast Reconstr Surg. 1999;104(4):1052-1053. 

16. Chae JB, Ohn J, Mun J-H. Dermoscopic features of digital mucous cysts: A study of 23 cases. J Dermatol. 2017;44(11):1309-1312. doi:10.1111/1346-8138.13892

17. Wang JP, Rancy SK, Dicarlo EF, Wolfe SW. Recurrent pigmented villonodular synovitis and multifocal giant cell tumor of the tendon sheath: case report. J Hand Surg Am. 2015;40(3):537-541. doi:10.1016/j.jhsa.2014.11.01

18. Smith PS, Pieterse AS, McClure J. Fibroma of tendon sheath. J Clin Pathol. 1982;35(8):842-848. 

19. Fotiadis E, Papadopoulos A, Svarnas T, Akritopoulos P, Sachinis NP, Chalidis BE. Giant cell tumour of tendon sheath of the digits. A systematic review. Hand (N Y). 2011;6(3):244-249. doi:10.1007/s11552-011-9341-9

20. Al-Qattan MM. Giant cell tumours of tendon sheath: Classification and recurrence rate. J Hand Surg Br. 2001;26(1):72-75. doi:10.1054/jhsb.2000.0522

21. Suresh SS, Zaki H. Giant cell tumor of tendon sheath: Case series and review of literature. J Hand Microsurg. 2010;2(2):67-71. doi:10.1007/s12593-9

cystic lesion

Diagnosis: Giant cell tumor of the tendon sheath

Figure 1. Fleshy, firm mass localized to the distal lateral index finger.

A giant cell tumor of the tendon sheath (GCTTS) is a benign neoplasm occurring most commonly in the hands and involves the synovial membrane of the tendon sheath, joints, and bursa (Figures 1 and 2).1,2 It is the second most common neoplasm in the hand and can also be found in the feet, knees, and spine.1,2 Though this neoplasm is relatively common overall, GCTTS is not frequently reported in dermatologic literature, most likely due to its commonality as well as treatment by hand surgeons.3 These tumors often develop on the volar aspects of fingers and adjacent skin is typically normal.4 GCTTS affects females more than males and typically presents between 30 and 50 years of age.5 GCTTS in the pediatric population is comparatively uncommon, though cases have been reported. A case series performed by Gholve and colleagues showed that GCTTS in pediatric patients behaves similarly to the adult neoplasm and is often solitary within a single digit. A small number of reports have shown multiple lesions in a single digit that were not interconnected.6 

Figure 2. Side view of the index finger tumor.

side view cystic lesion

The pathophysiology of a GCTTS is uncertain. Data from previous studies suggests that the etiology includes an inflammatory process arising from chronic antigenic stimulation, a reactive proliferation developing from the synovial lining of the tendon sheath/joint, or a lesion of monocyte/macrophage origin.5 GCTTS is classically treated with excision but demonstrates up to a 45% recurrence rate.1,7 This case of GCTTS in a 16-year-old patient highlights the importance of recognizing this cutaneous lesion in the pediatric population.

Clinical Presentation

GCTTS—classified as a benign soft tissue tumor—is a painless, slow-growing, well-circumscribed, and encapsulated mass with lobular architecture lined by fibrous bands.1,7 It is a locally invasive proliferative disorder that was first described by Jaffe and colleagues as a slowly progressive mass that occurs in association with villous or nodular overgrowth.2 Morphologic classification of GCTTS is divided into 2 types: nodular type (on hands), and diffuse type (seen on large synovial lined joints including the knees). 

In addition, a previous study by Geweiler and Wilson demonstrated trauma and multifocality as a possible etiology in 50% of cases. This study induced similar lesions with the extra-articular injection of blood in experimental animals.8 

In a case study with 71 patients, Monaghan described the histology of GCTTS that included cell types such as histiocytes, macrophage-mononuclear cells, osteoclast giant cells, and xanthomatous cells with variable Touton-type giant cells and lymphocytes. A higher mitotic rate of these cells was noted in all 71 cases.5 Our patient’s pathology showed giant cells and Touton-type cells admixed with lymphocytes (Figure 3). 

pathology

Figure 3. Pathology consistent with giant cell tumor of tendon sheath

While GCTTS is usually benign, there are reports of malignant GCTTS. It has been described in less than 20 cases. Sistla and colleagues described 1 case in which a recurrent GCTTS transformed into a malignant lesion over the course of 8 years. While this is extremely rare, it is something to be wary of when suspecting and treating a GCTTS.9

Differential Diagnosis

The differential diagnosis of GCTTS includes many tumors of the hand and digits including a glomus tumor, leiomyoma, blue rubber bleb, neuroma, spiradenoma, angiolipoma, digital mucus cyst, or fibroma. The Table provides a brief overview of the various tumors that a dermatologist must consider when evaluating a tumor on the digits.10-17 On histology, GCTTS can mimic other medical conditions and thus a thorough history, physical exam, excision, and histologic exam helps to properly diagnose the lesion and move forward with the proper treatment plan.18

table

Diagnosis and Management

GCTTS diagnosis is made via histology and treatment is through local excision. Approximately 25% of GCTTS are clinically diagnosed prior to surgery. A recurrence rate of up to 45% has been reported, imparting the importance of excision of a GCTTS carefully with magnification equipment.7 Possible risk factors for recurrence of GCTTS were demonstrated by Fotiadis and colleagues and include incomplete excision of the original mass, location at the distal interphalangeal joint of the finger, osseous pressure erosion, high mitotic activity, proximity to arthritic joint, tumors which are gene nm 23 negative, and type II tumors.19 Al-Qattan described a classification system for GCTTS in 2001, grouping the neoplasm into with or without a single pseudocapsule. Type II tumors (not surrounded by 1 pseudocapsule) had a recurrence rate of approximately 40%.20 In 2007, Gholve and colleagues conducted a study of GCTTS in the pediatric population and found that the recurrence rate in a case series of 29 patients was essentially 0%.6, 21 

Our Patient

Following the 4-mm punch biopsy, pathology revealed a GCTTS (Figure 4). The procedure was well tolerated and sutures were removed 2 weeks post-in-office removal. The entire specimen was removed at the time of biopsy and no further management was required. The patient had no evidence of recurrence, and in-office local excision was well tolerated.

excision

Figure 4. View of tumor during excision.

Conclusion

This article describes an unusual case of GCTTS in the index finger of a pediatric patient. GCTTS is a common benign tumor of the tendon sheath that normally presents between the third and fifth decade of life, making this patient a rather infrequent case. The pathogenesis of GCTTS is unknown but may be due to local trauma and the high mitotic rate of cells in the region. The diagnosis and treatment of GCTTS is meticulous excision to prevent recurrence. Further studies are necessary to understand the origin of GCTTS, but this tumor should be included in the differential of all unknown masses of the hand and fingers both in adults and the pediatric population. 

Dr Sheikh is a second-year dermatology resident at Larkin Community Hospital Palm Springs Campus in Hialeah, FL. 

Ms Bowles is a fourth-year medical student at Ohio University Heritage College of Osteopathic Medicine in Athens, OH.

Dr Hall is a third-year orthopedic surgery resident at SSM St. Anthony Bone and Joint Hospital in Oklahoma City, OK.

Dr Glick is a board certified dermatologist and dermatologic surgeon with clinical and academic practices in south Florida; director of the dermatology residency at the Larkin Hospital, Palm Springs Campus and clinical assistant professor of dermatology at the Herbert Wertheim College of Medicine, Miami, FL.

Disclosures: The authors report no relevant financial relationships.

References

1. Lucas DR. Tenosynovial giant cell tumor: Case report and review. Arch Pathol Lab Med. 2012;136(8):901-906. doi:10.5858/arpa.2012-0165-CR

2. Cho JM, Chang JH, Kim SH, Lee KS. Pediatric giant cell tumor of the tendon sheath of the craniocervical junction involving the occipital condyle. Childs Nerv Syst. 2016;32(1):175-179. doi:10.1007/s00381-015-2820-5

3. Richert B, Andr J. Laterosubungual giant cell tumor of the tendon sheath: An unusual location. J Am Acad Dermatol. 1999;41(2):347-348.

4. Zeinstra JS, Kwee RM, Kavanagh EC, van Hemert WL, Adriaensen ME. Multifocal giant cell tumor of the tendon sheath: Case report and literature review. Skeletal Radiol. 2013;42(3):447-450. doi:10.1007/s00256-012-1552-9

5. Monaghan H. Giant cell tumour of tendon sheath (localised nodular tenosynovitis): Clinicopathological features of 71 cases. J Clin Pathol. 2001;54(5):404-407. 

6. Gholve PA, Hosalkar HS, Kreiger PA, Dormans JP. Giant cell tumor of tendon sheath. J Pediatr Orthop. 2007;27(1):67-74. doi:10.1097/01.bpo.0000242380.95348.8b

7. Hwang JS, Fitzhugh VA, Gibson PD, Didesch J, Ahmed I. Multiple giant cell tumors of tendon sheath found within a single digit of a 9-year-old. Case Rep Orthop. 2016;2016:1834740. doi:10.1155/2016/1834740

8. Gehweiler JA, Wilson JW. Diffuse biarticular pigmented villonodular synovitis. Radiology. 1969;93(4):845-851. doi:10.1148/93.4.845

9. Sistla RJ, Vidyasagar JVS, Afroz T. Malignant pigmented villonodular synovitis-A rare entity. J Orthop Case Rep. 2014;4(4):9-11. doi:10.13107/jocr.2250-0685.214

10. Morey VM, Garg B, Kotwal PP. Glomus tumours of the hand: Review of literature. J Clin Orthop Trauma. 2016;7(4):286-291. doi:10.1016/j.jcot.2016.04.006

11. Boutayeb F, EI Ibrahimi A, Chraibi F, Znati K. Leiomyoma in an index finger: report of case and review of literature. Hand (N Y). 2008;3(3):210-211. doi:10.1007/s11552-008-9084-4

12. Suksamanapun N, Trakarnsanga A, Akaraviputh T. Blue rubber bleb nevus syndrome. Endoscopy. 2011;43(suppl 2):E411-E412. doi:10.1055/s-0030-1257043

13. Rhode CM, Jennings WD. Pacinian corpuscle neuroma of digital nerves. South Med J. 1975;68(1):86-89. 

14. Ohtsuka H, Tezuka K, Kumakiri M, Ohtsuki Y. Multiple eccrine spiradenomas on the hand, forearm and head. Dermatology. 2002;205(4):401-404. doi:10.1159/00006643

15. Weinzweig J, Minniti JG, Aswad BI, Bowen L. Angiolipoma of the finger masquerading as flexor tenosynovitis. Plast Reconstr Surg. 1999;104(4):1052-1053. 

16. Chae JB, Ohn J, Mun J-H. Dermoscopic features of digital mucous cysts: A study of 23 cases. J Dermatol. 2017;44(11):1309-1312. doi:10.1111/1346-8138.13892

17. Wang JP, Rancy SK, Dicarlo EF, Wolfe SW. Recurrent pigmented villonodular synovitis and multifocal giant cell tumor of the tendon sheath: case report. J Hand Surg Am. 2015;40(3):537-541. doi:10.1016/j.jhsa.2014.11.01

18. Smith PS, Pieterse AS, McClure J. Fibroma of tendon sheath. J Clin Pathol. 1982;35(8):842-848. 

19. Fotiadis E, Papadopoulos A, Svarnas T, Akritopoulos P, Sachinis NP, Chalidis BE. Giant cell tumour of tendon sheath of the digits. A systematic review. Hand (N Y). 2011;6(3):244-249. doi:10.1007/s11552-011-9341-9

20. Al-Qattan MM. Giant cell tumours of tendon sheath: Classification and recurrence rate. J Hand Surg Br. 2001;26(1):72-75. doi:10.1054/jhsb.2000.0522

21. Suresh SS, Zaki H. Giant cell tumor of tendon sheath: Case series and review of literature. J Hand Microsurg. 2010;2(2):67-71. doi:10.1007/s12593-9