A man with foot ulcer

ABSTRACT

A 59-year-old Malay man presented with a keratinising lesion over the dorsum of right toe. The resected specimen was an ulcerated necrotic skin covered lesion that measured 5 x 2.5 x 2.5 cm. The cut surface showed blackish powdery granular material embedded in nonviable tissue (Panel A; Haematoxylin and Eosin stain, B; Grocott (Silver) stain and C; Periodic Acid Schiff [PAS] stain). What is the diagnosis? Answer refer to page 238