Case Number : Case 2246 - 22 January 2019 Posted By: Iskander H. Chaudhry

epithelioid fibrous histiocytoma vs solitary reticulohistiocytoma

Reticulohistiocytoma

Reticulohistiocytoma

Agree. Reticulohistiocytoma for me too.

Well defined nodular dermal infiltrate, with ground-glass cells and scattered small collections of foamy cells, is in keeping with Reticulohistiocytoma, as my Colleagues have remarked.

Reticulohistiocytoma and fibrous histiocytoma were on my list of differential diagnosis, too. Looks like so far most people here favor reticulohistiocytoma. For my education can someone please comment on whether this lesion can be called xanthogranuloma? Great case to clarify some concepts!

It's clearly xanthogranulomatous as well as reticulohistiocytomatous (could by argued an encompassing term might be called for like solitary eruptive non-X histiocytoma or SEnXH for short). I liked the additional differential suggestion of epithelioid fibrous histiocytoma too. BTW I also thought about Spitz naevus and perineurioma but I guess these would be lower down.

I am with xanthogranuloma!