Tibial osteochondroma with thick cartilage which mimicked a chondrosarcoma: A case report.

We report a case of tibial osteochondroma in a 25-year-old female who presented with a palpable calf mass. This mass was associated with a thick cartilaginous cap on cross-sectional imaging, suggesting chondrosarcoma. A CT-guided biopsy was performed, and histology, however, was consistent with osteochondroma. Orthopedic oncology recommended surgical excision due to the potential high sampling error with chondroid lesions. The patient underwent surgical resection, resulting in a final diagnosis of osteochondroma. No post-surgical complications occurred, and a 12-month follow-up showed no evidence of local recurrence. This case highlights the atypical imaging feature of a thick cartilaginous cap in a benign etiology without malignant transformation.