Fig. 1: Spitz melanomas with HRAS mutations share features with HRAS mutant Spitz nevi.
From: Spitz melanoma is a distinct subset of spitzoid melanoma
a Low power view of case 14 which contained an HRASQ61R mutation. The melanoma is predominantly intradermal and has a broad distribution. b On higher power view, the melanocytes are epithelioid and pleomorphic and distributed as single cells and elongated nests in between dense sclerotic collagen bundles. Occasional intra-nuclear inclusions are noted. c Low power view of case 23 which contained an HRASG12D mutation. The melanoma is predominantly intradermal and broader than it is deep. d On higher power, superficial melanocytes are irregularly pigmented and deeper within the dermis. Dermal melanocytes have scant cytoplasm and hyperchromatic nuclei.
