Blastic plasmacytoid dendritic cell neoplasm presenting as violaceous forehead plaque

A 72-year-old man with a history of squamous cell carcinoma presented to the Portland VA with forehead discoloration. He was initially diagnosed with actinic damage and prescribed topical treatment. However, he returned to clinic months later with a large, violaceous forehead plaque. Upon biopsy, he was diagnosed with blastic plasmacytoid dendritic cell neoplasm (BPDCN), a rare hematological malignancy. This case report illustrates the importance of keeping BPDCN in the differential diagnosis for ecchymotic plaques that fail to respond to first line therapy.