Blastic plasmacytoid dendritic cell neoplasm skin biopsy

(A) Skin biopsy shows extensive lymphoid infiltration of the entire dermis. Note a Grenz zone is present between the epidermis and the infiltrate. No epidermal involvement is demonstrated. The skin biopsy showed that the tumor cells were positive for CD4, CD56, and CD68, but were negative for CD3, CD5, CD8, CD20, myeloperoxidase, and lysozyme. H&E, x4.
(B) High magnification of the skin biopsy shows immature nuclear chromatin pattern with occasional nucleoli. H&E, x100.