Isolated skin infiltration by a blastic plasmacytoid dendritic cell neoplasm

[摘要] A previously healthy 76-year-old woman presented with a slowly growing erythematous, painless papule on the left calf. The lesion progressively formed, within 3 months, a 5 × 3 cm indurated purplish nodule(Figure 1, panel A). Blood counts were normal and no sign of inflammatory diseases was found in the blood. A punch biopsy (Figure 1, panel D) of the calf lesion revealed diffuse dermic and hypodermic infiltrationby medium- to large-sized blasts, with convoluted nuclei and smallnucleoli (Figure 1, panel E). The phenotype of the blasts was CD4+(Figure 1, panel F), CD56+ (Figure 1, panel G), CD123+ (Figure 1,panel H), CD33+, TdT+/– (Figure 1, panel I), and MPO–, CD34–.