Subungual Extraskeletal Chondroma With Finger Nail Deformity: Case Report

We report a subungual extraskeletal chondroma with a convex nail deformity originating from the index finger in a 39-year-old man. The tumor was excised and its histopathology showed obvious nuclear pleomorphism. However, the Ki-67 (MIB-1) labeling index was less than 1%, indicating low proliferative activity; it was classified as an extraskeletal chondroma with atypical features. There was no recurrence over a 3-year postoperative period.