Enchondroma protuberans of the hand: A case report.

Enchondroma protuberans (EP) is a rare form of enchondroma which demonstrates exophytic growth outside the margins of the bony cortex. A previously healthy 18-year-old male presented with chronic painless palpable mass of the left third finger. Radiograph showed a well-circumscribed expansile lucent lesion in the middle phalanx of the left third finger. The magnetic resonance imaging confirmed an expansile cortical-based lesion extending through the cortex into the soft tissues, which demonstrated high T2 signal with internal foci with low to intermediate signal suggestive of internal chondroid matrix. The patient underwent surgical excision, curettage and bone grafting, and surgical pathology study confirmed the diagnosis of EP. A rare case of EP involving a phalanx of the hand was described in this study. Imaging, particularly magnetic resonance imaging, plays a key role for accurate preprocedural diagnosis.