Blastic plasmacytoid dendritic cell neoplasm presenting with a cutaneous tumor alone as the first symptom of onset: A case report and review of literature.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN), formerly named cluster of differentiation (CD)4(+)/CD56(+) haematodermic neoplasm or blastic natural killer cell lymphoma, is a rare and highly aggressive haematopoietic malignancy. BPDCN typically occurs in the elderly, with a marked predilection for cutaneous involvement. The present study describes a case of BPDCN occurring in a 79-year-old male. The patient presented with skin lesions alone, with no evidence of extracutaneous involvement during the course of the disease. BPDCN was diagnosed based on histological and immunohistochemical observations and the patient was subsequently treated with local radiotherapy alone. However, rapid disease progression occurred and the patient succumbed five months after being diagnosed. The current result therefore demonstrated that BPDCN is highly aggressive even without systemic dissemination, and that radiotherapy appears to be ineffective in treating this tumor. The present study emphasizes the importance of pathologists and dermatologists being aware of this uncommon disease in order to avoid misdiagnosis.