PMEL and angiomyolipoma: Desmin IHC reportedly has variable expression in angioleiomyoma, but some studies observed strong positivity in uterine angioleiomyoma much like in the presented tumor (Figure 2d).2,3,5 There is also observed weak and focal staining for CD34 by endothelial cells within angioleiomyoma, and in contrast to other tumors of pericyte origin (eg, angiomyolipoma and PEComa), HMB45 and MART1 are negative (this was also observed in the presented tumor: Figure 2f-h).