A 30-year-old African-American female with no previous history of skin cancer was referred to the dermatology clinic for the development of a solitary lesion on her right upper back. The patient stated that she first noticed what she thought was a skin tag on her back approximately 10 years ago. Since then, she reported that it had been progressively enlarging, which prompted her visit to the clinic. She denied any pruritus or pain associated with the lesion and denied any previous treatments. The patient had been previously healthy and denied any weight loss, fevers, night sweats or lymphadenopathy. The patient’s family and past medical history were negative for skin cancer or any similar lesion. A focused skin examination revealed a 3.5 cm x 3.5 cm pedunculated skin-colored, smooth nodule on the right scapula. It was soft and non-tender to palpation. No café-au-lait spots, neurological or develop- mental defects were appreciated. The nodule was excised and further histological examination was performed.
What Is Your Diagnosis?
See below for an answer and for more details.
Diagnosis: Pedunculated Lipofibroma
Pedunculated lipofibroma is a rare, benign connective tissue hamartoma characterized by mature ectopic adipocytes in the dermis.1 It is a sub- type of nevus lipo- matosus cutaneous superficialis (NLCS), which is classified into two types, the classical Hoffman-Zurhelle form and the pedunculated solitary form. 2 The only method to differentiate the two forms of NLCS is a thorough evaluation of the clinical presentation of the lesion. Histological examination is identical for both forms but is unique in discerning the pedunculated lipofibroma from other benign papillomas and soft tissue fibromas.
Historical Note
In 1921, Hoffmann and Zurhelle de- scribed the first case of NLCS in a 25-year-old man who presented with multiple soft nodules on the gluteal region. 3 In 1968,Weitzner reported on a 24-year-old Spanish-American male who presented with an asymptomatic small, solitary nodule on the scalp, which was present for 5 years. The biopsy was consistent with NLCS and the histological examination revealed mature fatty tissue in the dermis. 4 Because the lesion was solitary and located on the scalp rather than the pelvic or gluteal region, Weitzner referred to the lesion as solitary nevus lipomatosus cutaneus superficialis. Currently, the term “pedunculated lipofibroma” is used to denote solitary forms of NLCS. 5
Clinical Presentation
The two subtypes of NLCS are differentiated based on clinical presentation. The solitary form can present as a single pedunculated or dome-shaped papule to nodule or very rarely a plaque. 1 It is a slow-growing tumor that is usually asymptomatic and skin-colored. Because the duration before patients seek therapy ranges from 2 to 10 years, the size of the lesion has a wide variance, presenting from 0.5 cm to 6 cm. Although there have been cases involving the scalp, neck, shoulder, groin, back, knee, ear and eye, pedunculated lipofibromas are predominantly found on the buttocks and thighs. 6,7 Pedunculated lipofibroma is rare in the population and presents after the second decade of life. 2 However, the rarity of this diagnosis could be attributed to underreporting of the condition, which may originate from the lack of recognition and the failure to differentiate from other benign papillomas. 8 There has been no evidence of correlation with sex or ethnicity. The other form of NLCS is the Hoffmann-Zurhelle form, or classic form, characterized by multiple soft, non-tender pedunculated papules to nodules, which commonly coalesce to form plaques. The classic form has a predilection for the gluteal, pelvic and lower back region, and lesions are present at birth or develop in the first 2 decades of life. 9
Pathogenesis
The pathogenesis has not been clearly identified, although several theories have been postulated. The displacement of subcutaneous adipocytes into the dermis is one such theory, which hypothesizes that fat located in the subcutis becomes dislodged and enters the overlying dermis. 1 Adipose metaplasia via degeneration of dermal connective tissue is another theory of pathogenesis that links the deposition of fat from a primary degenerative change in the connective tissue. However, this theory has fallen out of favor due to the lack of evidence of degeneration of the connective tissue. 1 The last theory to be proposed is the adipocyte deposition from differentiating lipoblasts found on dermal blood vessels. The differentiating lipoblasts are thought to be composed of multiple fat vacuoles that eventually develop into mature adipocytes. 1,10
Diagnosis and Histology
Diagnosis of pedunculated lipofibroma is made definitively by biopsy and histological exam. The epidermis reveals slight acanthosis with variable hyperkeratosis and blunted rete ridges. A central core with scattered lobules of mature, ectopic adipocytes is found infiltrating the papillary and reticular dermis and represents the key histological abnormality in both forms of NLCS.The islands of fatty tissue are unencapsulated, occasionally continuous with the subcutis focally, and entrapped between bundles of dermal collagen fibers and adnexal structures.1,2,11 The dermal-subcutaneous interface is greatly distorted secondary to the marked increase in mature adipose tissue. There is a variable increase in the number of blood vessels and fibroblasts, and a marked increase in deposition of mucopolysaccharides in the reticular dermis. The deposition of mucopolysaccharides in the dermis was theorized to represent mucoid degeneration of the stroma as found in other soft-tissue abnormalities. 1 A perivascular lymphohistiocytic infiltrate is commonly observed in the dermis, and mast cells are also found in the adipose tissue.
Differential Diagnosis
The differential diagnosis of pedunculated lipofibroma includes any benign papillomas found on any part of the body and onset at any age. Common differentials are listed and described in Table 1.
Management and Prognosis
Due to the benign nature of pedunculated lipofibromas, no treatment is needed unless for cosmetic reasons. When treatment is desired, surgical excision is curative and the gold standard of treatment, rarely resulting in recurrence. 6 A study of 32 reported cases of pedunculated lipofibroma resulted with no recurrence 3 years post-excision. 1 The classical multi-from NLCS has been associated with follicular papules, hypertrophic pilosebaceous units, pedunculated basal cell carcinoma and angiokeratoma. 16 The pedunculated form of NLCS is considered benign; however, there is evolving evidence that the presence of these nodules can be associated with serious endocrine conditions such as diabetes mellitus and Cushing’s disease. 1,17 In a study of 32 participants in Japan, there was a 21% incidence of diabetes mellitus in participants with reported pedunculated lipofibroma compared to the Japanese population incidence of 3.8%.1 Therefore, the identification and accurate diagnosis of these lesions warrants an endocrine work- up when symptoms are present.
Summary and Future Directions
First described by Hoffmann and Zurhelle in 1921, NLCS is a rare, benign cutaneous harmatoma characterized by a dermal infiltration of mature adipocytes. Clinically, NCLS is subdivided into two forms, classical and solitary. The solitary form, referred to as a pedunculated lipofibroma, presents during adulthood as a single pedunculated papule on any site of the body, while the classical form presents as multiple papules predominantly on the pelvic or gluteal region at birth or during childhood. Due to the rarity of the condition, epidemiologic data is scarce. While there are several competing hypotheses, the exact pathogenesis is currently un- known.Treatment consists of surgical excision, which is curative and results in low recurrence. Further research is necessary to expose the true pathogenesis of NLCS and the association of these cutaneous lesions with endocrine conditions.
Patient Management
The patient in the case presentation was diagnosed with pedunculated lipofibroma based on biopsy and histological exam. The sole lesion was surgically excised, and the patient responded well to treatment. Upon follow-up at 1 month, the lesion had not recurred. Ms. Sharma is a second year medical student at the University of South Florida College of Medicine in Tampa. Mr.Suszko is a fourth year medical student at the University of Nevada School of Medicine in Reno. Dr. Khachemoune, the Section Editor of Derm Dx, is with Department of Dermatology, State University of New York, Brooklyn, NY. Disclosure: The authors have no conflicts of interest or financial disclosures to report.
A 30-year-old African-American female with no previous history of skin cancer was referred to the dermatology clinic for the development of a solitary lesion on her right upper back. The patient stated that she first noticed what she thought was a skin tag on her back approximately 10 years ago. Since then, she reported that it had been progressively enlarging, which prompted her visit to the clinic. She denied any pruritus or pain associated with the lesion and denied any previous treatments. The patient had been previously healthy and denied any weight loss, fevers, night sweats or lymphadenopathy. The patient’s family and past medical history were negative for skin cancer or any similar lesion. A focused skin examination revealed a 3.5 cm x 3.5 cm pedunculated skin-colored, smooth nodule on the right scapula. It was soft and non-tender to palpation. No café-au-lait spots, neurological or develop- mental defects were appreciated. The nodule was excised and further histological examination was performed.
What Is Your Diagnosis?
See below for an answer and for more details.
Diagnosis: Pedunculated Lipofibroma
Pedunculated lipofibroma is a rare, benign connective tissue hamartoma characterized by mature ectopic adipocytes in the dermis.1 It is a sub- type of nevus lipo- matosus cutaneous superficialis (NLCS), which is classified into two types, the classical Hoffman-Zurhelle form and the pedunculated solitary form. 2 The only method to differentiate the two forms of NLCS is a thorough evaluation of the clinical presentation of the lesion. Histological examination is identical for both forms but is unique in discerning the pedunculated lipofibroma from other benign papillomas and soft tissue fibromas.
Historical Note
In 1921, Hoffmann and Zurhelle de- scribed the first case of NLCS in a 25-year-old man who presented with multiple soft nodules on the gluteal region. 3 In 1968,Weitzner reported on a 24-year-old Spanish-American male who presented with an asymptomatic small, solitary nodule on the scalp, which was present for 5 years. The biopsy was consistent with NLCS and the histological examination revealed mature fatty tissue in the dermis. 4 Because the lesion was solitary and located on the scalp rather than the pelvic or gluteal region, Weitzner referred to the lesion as solitary nevus lipomatosus cutaneus superficialis. Currently, the term “pedunculated lipofibroma” is used to denote solitary forms of NLCS. 5
Clinical Presentation
The two subtypes of NLCS are differentiated based on clinical presentation. The solitary form can present as a single pedunculated or dome-shaped papule to nodule or very rarely a plaque. 1 It is a slow-growing tumor that is usually asymptomatic and skin-colored. Because the duration before patients seek therapy ranges from 2 to 10 years, the size of the lesion has a wide variance, presenting from 0.5 cm to 6 cm. Although there have been cases involving the scalp, neck, shoulder, groin, back, knee, ear and eye, pedunculated lipofibromas are predominantly found on the buttocks and thighs. 6,7 Pedunculated lipofibroma is rare in the population and presents after the second decade of life. 2 However, the rarity of this diagnosis could be attributed to underreporting of the condition, which may originate from the lack of recognition and the failure to differentiate from other benign papillomas. 8 There has been no evidence of correlation with sex or ethnicity. The other form of NLCS is the Hoffmann-Zurhelle form, or classic form, characterized by multiple soft, non-tender pedunculated papules to nodules, which commonly coalesce to form plaques. The classic form has a predilection for the gluteal, pelvic and lower back region, and lesions are present at birth or develop in the first 2 decades of life. 9
Pathogenesis
The pathogenesis has not been clearly identified, although several theories have been postulated. The displacement of subcutaneous adipocytes into the dermis is one such theory, which hypothesizes that fat located in the subcutis becomes dislodged and enters the overlying dermis. 1 Adipose metaplasia via degeneration of dermal connective tissue is another theory of pathogenesis that links the deposition of fat from a primary degenerative change in the connective tissue. However, this theory has fallen out of favor due to the lack of evidence of degeneration of the connective tissue. 1 The last theory to be proposed is the adipocyte deposition from differentiating lipoblasts found on dermal blood vessels. The differentiating lipoblasts are thought to be composed of multiple fat vacuoles that eventually develop into mature adipocytes. 1,10
Diagnosis and Histology
Diagnosis of pedunculated lipofibroma is made definitively by biopsy and histological exam. The epidermis reveals slight acanthosis with variable hyperkeratosis and blunted rete ridges. A central core with scattered lobules of mature, ectopic adipocytes is found infiltrating the papillary and reticular dermis and represents the key histological abnormality in both forms of NLCS.The islands of fatty tissue are unencapsulated, occasionally continuous with the subcutis focally, and entrapped between bundles of dermal collagen fibers and adnexal structures.1,2,11 The dermal-subcutaneous interface is greatly distorted secondary to the marked increase in mature adipose tissue. There is a variable increase in the number of blood vessels and fibroblasts, and a marked increase in deposition of mucopolysaccharides in the reticular dermis. The deposition of mucopolysaccharides in the dermis was theorized to represent mucoid degeneration of the stroma as found in other soft-tissue abnormalities. 1 A perivascular lymphohistiocytic infiltrate is commonly observed in the dermis, and mast cells are also found in the adipose tissue.
Differential Diagnosis
The differential diagnosis of pedunculated lipofibroma includes any benign papillomas found on any part of the body and onset at any age. Common differentials are listed and described in Table 1.
Management and Prognosis
Due to the benign nature of pedunculated lipofibromas, no treatment is needed unless for cosmetic reasons. When treatment is desired, surgical excision is curative and the gold standard of treatment, rarely resulting in recurrence. 6 A study of 32 reported cases of pedunculated lipofibroma resulted with no recurrence 3 years post-excision. 1 The classical multi-from NLCS has been associated with follicular papules, hypertrophic pilosebaceous units, pedunculated basal cell carcinoma and angiokeratoma. 16 The pedunculated form of NLCS is considered benign; however, there is evolving evidence that the presence of these nodules can be associated with serious endocrine conditions such as diabetes mellitus and Cushing’s disease. 1,17 In a study of 32 participants in Japan, there was a 21% incidence of diabetes mellitus in participants with reported pedunculated lipofibroma compared to the Japanese population incidence of 3.8%.1 Therefore, the identification and accurate diagnosis of these lesions warrants an endocrine work- up when symptoms are present.
Summary and Future Directions
First described by Hoffmann and Zurhelle in 1921, NLCS is a rare, benign cutaneous harmatoma characterized by a dermal infiltration of mature adipocytes. Clinically, NCLS is subdivided into two forms, classical and solitary. The solitary form, referred to as a pedunculated lipofibroma, presents during adulthood as a single pedunculated papule on any site of the body, while the classical form presents as multiple papules predominantly on the pelvic or gluteal region at birth or during childhood. Due to the rarity of the condition, epidemiologic data is scarce. While there are several competing hypotheses, the exact pathogenesis is currently un- known.Treatment consists of surgical excision, which is curative and results in low recurrence. Further research is necessary to expose the true pathogenesis of NLCS and the association of these cutaneous lesions with endocrine conditions.
Patient Management
The patient in the case presentation was diagnosed with pedunculated lipofibroma based on biopsy and histological exam. The sole lesion was surgically excised, and the patient responded well to treatment. Upon follow-up at 1 month, the lesion had not recurred. Ms. Sharma is a second year medical student at the University of South Florida College of Medicine in Tampa. Mr.Suszko is a fourth year medical student at the University of Nevada School of Medicine in Reno. Dr. Khachemoune, the Section Editor of Derm Dx, is with Department of Dermatology, State University of New York, Brooklyn, NY. Disclosure: The authors have no conflicts of interest or financial disclosures to report.
A 30-year-old African-American female with no previous history of skin cancer was referred to the dermatology clinic for the development of a solitary lesion on her right upper back. The patient stated that she first noticed what she thought was a skin tag on her back approximately 10 years ago. Since then, she reported that it had been progressively enlarging, which prompted her visit to the clinic. She denied any pruritus or pain associated with the lesion and denied any previous treatments. The patient had been previously healthy and denied any weight loss, fevers, night sweats or lymphadenopathy. The patient’s family and past medical history were negative for skin cancer or any similar lesion. A focused skin examination revealed a 3.5 cm x 3.5 cm pedunculated skin-colored, smooth nodule on the right scapula. It was soft and non-tender to palpation. No café-au-lait spots, neurological or develop- mental defects were appreciated. The nodule was excised and further histological examination was performed.
What Is Your Diagnosis?
See below for an answer and for more details.
Diagnosis: Pedunculated Lipofibroma
Pedunculated lipofibroma is a rare, benign connective tissue hamartoma characterized by mature ectopic adipocytes in the dermis.1 It is a sub- type of nevus lipo- matosus cutaneous superficialis (NLCS), which is classified into two types, the classical Hoffman-Zurhelle form and the pedunculated solitary form. 2 The only method to differentiate the two forms of NLCS is a thorough evaluation of the clinical presentation of the lesion. Histological examination is identical for both forms but is unique in discerning the pedunculated lipofibroma from other benign papillomas and soft tissue fibromas.
Historical Note
In 1921, Hoffmann and Zurhelle de- scribed the first case of NLCS in a 25-year-old man who presented with multiple soft nodules on the gluteal region. 3 In 1968,Weitzner reported on a 24-year-old Spanish-American male who presented with an asymptomatic small, solitary nodule on the scalp, which was present for 5 years. The biopsy was consistent with NLCS and the histological examination revealed mature fatty tissue in the dermis. 4 Because the lesion was solitary and located on the scalp rather than the pelvic or gluteal region, Weitzner referred to the lesion as solitary nevus lipomatosus cutaneus superficialis. Currently, the term “pedunculated lipofibroma” is used to denote solitary forms of NLCS. 5
Clinical Presentation
The two subtypes of NLCS are differentiated based on clinical presentation. The solitary form can present as a single pedunculated or dome-shaped papule to nodule or very rarely a plaque. 1 It is a slow-growing tumor that is usually asymptomatic and skin-colored. Because the duration before patients seek therapy ranges from 2 to 10 years, the size of the lesion has a wide variance, presenting from 0.5 cm to 6 cm. Although there have been cases involving the scalp, neck, shoulder, groin, back, knee, ear and eye, pedunculated lipofibromas are predominantly found on the buttocks and thighs. 6,7 Pedunculated lipofibroma is rare in the population and presents after the second decade of life. 2 However, the rarity of this diagnosis could be attributed to underreporting of the condition, which may originate from the lack of recognition and the failure to differentiate from other benign papillomas. 8 There has been no evidence of correlation with sex or ethnicity. The other form of NLCS is the Hoffmann-Zurhelle form, or classic form, characterized by multiple soft, non-tender pedunculated papules to nodules, which commonly coalesce to form plaques. The classic form has a predilection for the gluteal, pelvic and lower back region, and lesions are present at birth or develop in the first 2 decades of life. 9
Pathogenesis
The pathogenesis has not been clearly identified, although several theories have been postulated. The displacement of subcutaneous adipocytes into the dermis is one such theory, which hypothesizes that fat located in the subcutis becomes dislodged and enters the overlying dermis. 1 Adipose metaplasia via degeneration of dermal connective tissue is another theory of pathogenesis that links the deposition of fat from a primary degenerative change in the connective tissue. However, this theory has fallen out of favor due to the lack of evidence of degeneration of the connective tissue. 1 The last theory to be proposed is the adipocyte deposition from differentiating lipoblasts found on dermal blood vessels. The differentiating lipoblasts are thought to be composed of multiple fat vacuoles that eventually develop into mature adipocytes. 1,10
Diagnosis and Histology
Diagnosis of pedunculated lipofibroma is made definitively by biopsy and histological exam. The epidermis reveals slight acanthosis with variable hyperkeratosis and blunted rete ridges. A central core with scattered lobules of mature, ectopic adipocytes is found infiltrating the papillary and reticular dermis and represents the key histological abnormality in both forms of NLCS.The islands of fatty tissue are unencapsulated, occasionally continuous with the subcutis focally, and entrapped between bundles of dermal collagen fibers and adnexal structures.1,2,11 The dermal-subcutaneous interface is greatly distorted secondary to the marked increase in mature adipose tissue. There is a variable increase in the number of blood vessels and fibroblasts, and a marked increase in deposition of mucopolysaccharides in the reticular dermis. The deposition of mucopolysaccharides in the dermis was theorized to represent mucoid degeneration of the stroma as found in other soft-tissue abnormalities. 1 A perivascular lymphohistiocytic infiltrate is commonly observed in the dermis, and mast cells are also found in the adipose tissue.
Differential Diagnosis
The differential diagnosis of pedunculated lipofibroma includes any benign papillomas found on any part of the body and onset at any age. Common differentials are listed and described in Table 1.
Management and Prognosis
Due to the benign nature of pedunculated lipofibromas, no treatment is needed unless for cosmetic reasons. When treatment is desired, surgical excision is curative and the gold standard of treatment, rarely resulting in recurrence. 6 A study of 32 reported cases of pedunculated lipofibroma resulted with no recurrence 3 years post-excision. 1 The classical multi-from NLCS has been associated with follicular papules, hypertrophic pilosebaceous units, pedunculated basal cell carcinoma and angiokeratoma. 16 The pedunculated form of NLCS is considered benign; however, there is evolving evidence that the presence of these nodules can be associated with serious endocrine conditions such as diabetes mellitus and Cushing’s disease. 1,17 In a study of 32 participants in Japan, there was a 21% incidence of diabetes mellitus in participants with reported pedunculated lipofibroma compared to the Japanese population incidence of 3.8%.1 Therefore, the identification and accurate diagnosis of these lesions warrants an endocrine work- up when symptoms are present.
Summary and Future Directions
First described by Hoffmann and Zurhelle in 1921, NLCS is a rare, benign cutaneous harmatoma characterized by a dermal infiltration of mature adipocytes. Clinically, NCLS is subdivided into two forms, classical and solitary. The solitary form, referred to as a pedunculated lipofibroma, presents during adulthood as a single pedunculated papule on any site of the body, while the classical form presents as multiple papules predominantly on the pelvic or gluteal region at birth or during childhood. Due to the rarity of the condition, epidemiologic data is scarce. While there are several competing hypotheses, the exact pathogenesis is currently un- known.Treatment consists of surgical excision, which is curative and results in low recurrence. Further research is necessary to expose the true pathogenesis of NLCS and the association of these cutaneous lesions with endocrine conditions.
Patient Management
The patient in the case presentation was diagnosed with pedunculated lipofibroma based on biopsy and histological exam. The sole lesion was surgically excised, and the patient responded well to treatment. Upon follow-up at 1 month, the lesion had not recurred. Ms. Sharma is a second year medical student at the University of South Florida College of Medicine in Tampa. Mr.Suszko is a fourth year medical student at the University of Nevada School of Medicine in Reno. Dr. Khachemoune, the Section Editor of Derm Dx, is with Department of Dermatology, State University of New York, Brooklyn, NY. Disclosure: The authors have no conflicts of interest or financial disclosures to report.
