A case of deforming pachydermodactyly.

We report a 39-year-old man with pachydermodactyly resulting in progressive digital deformation. Pachydermodactyly is a rare superficial benign digital fibromatosis affecting the proximal interphalangeal joints (PIPs). Our patient had flexion deformities and mal-alignment primarily at the PIPs with associated soft tissue swelling. Radiographs revealed nonerosive subluxation. Surgical examination and biopsy with subsequent immunohistopathological study, revealed increased collagen production and proliferation from both fibroblasts and myofibroblasts consistent with pachydermodactyly. This patient differs from cases previously reported as the extent of soft tissue involvement altered the integrity of the articular supporting structures. This has resulted in deformity and functional impairment.