Photomicrograph of the skin lesion of case 1. (A) Low-power view showed a well-circumscribed epidermal mass composed of basaloid lobules with a fibrous pseudocapsule. (B) Distinct appearance of centrolobular cell balls with undifferentiated basaloid cells displaying peripheral palisading and myxiod stroma. (C) CK5/6 immunoreactivity was more intense in the outer layer tumor cells than those within the round nests. (D) The peripheral rim of palisading basaloid cells were stained with Bcl-2, along with the central part non-stained, giving the appearance of rings.
Chen et al. Diagnostic Pathology 2013 8:210 doi:10.1186/1746-1596-8-210