Affiliation:
1. Division of Orthopaedic Oncology, Department of Orthopaedics, VPS Lakeshore Hospital, Kochi, Kerala, India
Abstract
Osteochondromas are one of the most common benign neoplasms. Malignant transformation of a solitary osteochondroma to secondary chondrosarcoma is very rare, ranging from 1% to 2%. A new onset of pain, rapid growth of lesion after the closure of the growth plate, and cartilage cap thickness of more than 2 cm in adults and more than 3 cm in children are features suggestive of malignant transformation. Excision of the tumor with free margins is the treatment of choice. We report the case of a 33-year-old man with complaints of pain and progressive swelling over the right axilla. X-ray and MRI features were suggestive of malignant transformation, which was confirmed by histopathology. He underwent a wide excision with tumor-free margins. At 14 months of follow-up, he is asymptomatic with no clinical and radiological signs of recurrence. Malignant transformation of a solitary osteochondroma is extremely rare. High index of clinical and radiological suspicion is mandatory for early diagnosis and prompt management, thereby improving the prognosis and overall survival.