Bone Formation in Cutaneous Nodules on the Leg: A Quiz

Abstract

A 74-year-old man presented with several weeks' history of multiple cutaneous nodules and plaques on his right leg ( Fig. 1a). Histopathology revealed infiltrating epithelioid, hyperchromatic and pleomorphic tumour cells, mainly arranged in strands. In addition, there were areas of bony trabeculae rimmed by neoplastic cells (Fig. 1b). Ten months previously the patient had been diagnosed with an ulcerated acral lentiginous melanoma of his right hallux, measuring 14 mm in depth. Amputation of the hallux and inguinal lymph node dissection were performed as the sentinel lymph node was positive. Fig. 1. (a) Right thigh with multiple cutaneous nodules and plaques. (b) Punch biopsy of the nodules revealing areas with bony trabeculae rimmed by neoplastic cells (haematoxylin-eosin, original magnification ×100).