Onychomatricoma of the Nail Bed

Abstract

Onychomatricoma is a rare and specific benign tumor of the nail complex, with uncertain etiology. The avulsion of the nail plate reveals cavitations and orifices in its proximal extremity. These are associated with villous tumor formations generating digitiform projections at the nail matrix – typical intraoperative findings. We report a rare case of onychomatricoma in which the nail bed was predominantly affected and show evidence of its clinical, intraoperative, and histopathological presentation. The various descriptions of the disease report that its origin is restricted to the nail matrix, leading to secondary changes in the nail plate.

Onychomatricoma on the fourth toenail: A rare tumor in a rare localization

“…7 Intraoperatively, a filamentous tumor with digitiform projections that penetrate the nail plate leading to woodworm-like cavities is usually found. 10,11 Histopathological evaluation characteristically exhibits a fibroepithelial tumor composed of a proximal pedunculated base and a distal zone with multiple epithelial digitations. 2,3 A biphasic fibrous stroma, superficially cellular and deeply collagenized and relatively hypocellular, is present throughout the tumor.…”