You’ve heard of benign fibrous histiocytomas and their cutaneous (skin) equivalent aka dermatofibroma or “DF” for short (very common small skin lesions predominately on arms/legs)

BUT have you heard of an #EpithelioidFibrousHistiocytoma ? These are still benign but can look a bit scary under the microscope - big cells, big nuclei, big nucleoli, multinucleated cells, few mitoses for good measure 😐

Here’s one under my #microscope at 100x (just showing the top of the lesion as I didn’t have time to scan the whole thing for this toot - the area under the black line in the second pic), the dense pink band at the top is the epidermis - the part of skin you can touch).

Not shown are the immunostains I also used (positive for F13a, some scattered CD68 cells; negative for SOX-10 (melanoma marker) and pancytokeratin (carcinoma marker); vascular stains only highlighted vessels). And I showed it to a colleague too, to ensure we’re in agreement.

#pathology #bstpath #pathart #medmastodon #pathmastodon