Case Number : Case 4064 - 18 August 2022 Posted By: Saleem Taibjee

Lymphoepithelioma-like carcinoma..

Low power I considered epithelioid hemangioma (ALHE), but I don't see any eos. Seems young for carcinoma. Some type of Spitz nevus? I'd do some stains including keratins, and vascular and melanocytic markers.

This could be TRAPP (t cell rich angiomatoid polyploid pseudolymphoma) vs APACHE

Could it be cutaneous epithelioid angiomatous nodule. Don't see eosinophils, but I think in contrast to ALHE, eosinophils are not prominent in cutaneous epithelioid angiomatous  nodule. 

Interesting to see the various differential diagnosis proposed.

This was in fact a Spitz, ALK-positive (see below). Arguably it is atypical given the inflammatory reaction, but I suspected that this is secondary to trauma, and with an overall likely benign course.

These days I tend to request a panel including ALK, ROS-1 and NTRK (and sometimes BAP-1) to help classify such lesions.

BW

Saleem