Subungual pleomorphic fibroma: a case report and review of the literature.

We describe an interesting case of pleomorphic fibroma of the subungual region in a middle aged woman who presented with a recurrence of thickening, lateral ridging, and a midline split of the right third fingernail, 20 years after initial excision. Histology of the specimen demonstrated hyperchromatic stellate cells within the superficial corneum, which were CD34 positive, consistent with a pleomorphic fibroma. Pleomorphic fibroma is a rare mesenchymal neoplasm characterized by atypical spindled cells amidst a collagenous stroma. It is a benign, slow growing tumor that has only been reported in the subungual region twice previously. Although histology may show cellular atypia, the slow-growing benign nature of the tumor, reassuring features histologically i.e low cellularity, and lack of myxomatous change in the stroma, make a conservative approach to therapy reasonable.