Keys To Recognizing Chondrosarcomas In The Foot
Bone tumors of the foot are rare with approximately 3 to 6 percent of all bone tumors occurring in the foot.1-4 Chondrosarcomas are the most common malignant tumor of the foot but they still arise infrequently as this type of tumor has more of a predilection for the flat bones of the pelvis, scapula and the diaphysis of long bones. The majority of all bone tumors occurring in the foot are benign enchondromas, chondromyxoid fibromas and chondroblastomas.2,5,6
While having benign behavior, enchondromas cytologically tend to show features suggestive of malignancy, including high cellularity, enlarged nuclei and double nucleated cells.7 Radiographically, it can be difficult to distinguish low-grade chondrosarcomas from benign lesions. These radiographic and histologic features can make it difficult to differentiate benign lesions from malignant chondrosarcoma.
Chondrosarcomas can be primary or can develop from malignant degeneration of enchondromas or the cartilaginous cap of osteochondromas. Chondrosarcomas can be associated with several preexisting conditions, including Ollier disease, multiple osteochondromatosis and Maffucci syndrome.5,8 Ollier disease develops in childhood and is characterized by the development of numerous enchondromas developing near the cartilaginous growth plate.9 Maffucci syndrome is characterized by the presence of multiple enchondromas but is also associated with hemangiomas and occasional lymphangiomas.10 Multiple osteochondromatosis is characterized by the development of numerous osteochondromas in areas of active bone growth, particularly the metaphysis of the long bones.11
Nearly all chondrosarcomas originate from the medullary canal of the affected bone. The most common radiographic features of chondrosarcoma are endosteal scalloping, cortical expansion and cortical destruction. Other commonly observed features include associated soft tissue mass and a calcified matrix that appears mottled or ring-like.12
The age at the diagnosis of chondrosarcoma is quite variable, ranging from teens to the ninth decade, with the majority of cases being diagnosed between the fourth and seventh decades.5,13
Chondrosarcomas show no sex predilection. The most common sites for chondrosarcomas in the foot are the calcaneus, talus, metatarsals and phalanges, but researchers have reported chondrosarcomas in nearly every foot bone including the sesamoids, cuboid and cuneiforms.5,14
Common presenting symptoms include pain, swelling, pain with swelling and a rapidly growing, painful mass. The clinical course of chondrosarcomas is variable, ranging from slow growing without metastasis to aggressive forms with rapid growth, soft tissue extension and metastasis.
In slow-growing, low-grade lesions, the diagnosis of chondrosarcoma is frequently delayed. Despite frequent delays in diagnosis, the rate of metastasis and death associated with sarcomas of the foot is markedly reduced in comparison to sarcomas in proximal anatomic sites.15 Delayed diagnosis frequently occurs with malignant bone tumors of the foot. This is likely due to the less aggressive nature of sarcomas in this location in comparison to other anatomic locations.15 Brotzman and colleagues found that a delay in diagnosis of foot sarcomas did not affect the occurrence of metastasis, or have any effect on five-year and 10-year survival rates.14
Currently, treating physicians use multimodal therapy, combining surgery and chemotherapy for the treatment of sarcomas. The majority of patients receiving treatment for chondrosarcoma have salvage surgery of the limb but the small compartments of the foot can allow extra-compartment spread, necessitating amputation.16 Inadequate surgical resection is associated with an eightfold risk of developing local recurrence and local recurrence is associated with a significant increase in metastasis and a reduced survival rate.14
While rare, chondrosarcomas remain the most common malignant neoplasm affecting the foot. Given their frequently slow-growing nature as well as their potential to develop from common benign cartilaginous neoplasms, podiatric surgeons should maintain a level of clinical suspicion for these tumors. Given the potential for metastasis and death associated with chondrosarcoma, suspicion for this tumor should prompt further workup and oncology consultation.
References
1. Kilgore WB, Parrish WM. Calcaneal tumors and tumor-like conditions. Foot Ankle Clin. 2005;10(3):541-565, vii.
2. Ludwig K. [Tumors of the foot skeleton]. Radiologe. 2007;47(3):240, 242-249.
3. Buchner M, Bernd L, Zahlten-Hinguranage A, Sabo D. [Bone and soft-tissue tumors of the foot and ankle]. Chirurg. 2005;76(4):391-397.
4. Ozdemir HM, Yildiz Y, Yilmaz C, Saglik Y. Tumors of the foot and ankle: analysis of 196 cases. J Foot Ankle Surg. 1997;36(6):403-408.
5. Ogose A, Unni KK, Swee RG, May GK, Rowland CM, Sim FH. Chondrosarcoma of small bones of the hands and feet. Cancer. 1997;80(1):50-59.
6. Murari TM, Callaghan JJ, Berrey BH, Jr., Sweet DE. Primary benign and malignant osseous neoplasms of the foot. Foot Ankle. 1989;10(2):68-80.
7. Unni KK. Dahlin's Bone Tumors: General Aspects and Data on 11,087 Cases, Fifth Edition, Lippincott-Raven, Philadelphia, 1996.
8. Wicks IP, Fleming A. Chondrosarcoma of the calcaneum and massive soft tissue calcification in a patient with hereditary and acquired connective tissue diseases. Ann Rheum Dis. 1987;46(4):346-348.
9. Silve C, Juppner H. Ollier disease. Orphanet J Rare Dis. 2006;1:37.
10. Gupta N, Kabra M. Maffucci syndrome. Indian Pediatr. 2007;44(2):149-150.
11. McBride WZ. Hereditary multiple exostoses. Am Family Phys. 1988;38(3):191-192.
12. Merchan EC, Sanchez-Herrera S, Gonzalez JM. Secondary chondrosarcoma. Four cases and review of the literature. Acta Orthop Belg. 1993;59(1):76-80.
13. De Moraes FB, Linhares ND, de Souza Domingues PM, Warzocha VN, Soares JM. Calcaneal chondrosarcoma: a case report. Rev Bras Ortop. 2014;49(4):409-413.
14. Brotzmann M, Hefti F, Baumhoer D, Krieg AH. Do malignant bone tumors of the foot have a different biological behavior than sarcomas at other skeletal sites? Sarcoma. 2013;2013:767960.
15. Zeytoonjian T, Mankin HJ, Gebhardt MC, Hornicek FJ. Distal lower extremity sarcomas: frequency of occurrence and patient survival rate. Foot & ankle international. 2004;25(5):325-330.
16. Li J, Guo Z, Pei GX, Wang Z, Chen GJ, Wu ZG. Limb salvage surgery for calcaneal malignancy. J Surg Oncol. 2010;102(1):48-53.
