Blastic plasmacytoid dendritic cell neoplasm.

Blastic plasmacytoid dendritic cell neoplasm is an uncommon, aggressive hematologic neoplasm carrying a poor prognosis with a median survival of one year, making early detection vital. Patients present with a number of characteristic cutaneous manifestations and are treated with chemotherapy and hematopoietic stem cell transplantation, which may improve survival. In this case, a 65-year-old man with a history of basal cell carcinoma presented with a nodule on his forehead with a honey-crusted border. Although the patient was treated with intralesional triamcinolone and a 7-day course of cephalexin for concurrent staphylococcal infection, the patient reported rapid growth of the nodule, new ecchymosis and edema involving his right cheek, and erythematous patches of the right temple and neck. Biopsy of lesions and  immunohistochemical analysis confirmed the diagnosis of blastic plasmacytoid dendritic cell neoplasm. The patient was referred for further management, leading to sustained complete remission at 18 months after hematopoietic stem cell transplantation. Because blastic plasmacytoid dendritic cell neoplasm has varied cutaneous presentations that often mimic benign disease, particularly when presenting as bruise-like lesions, providers must maintain a high index of clinical suspicion and willingness to biopsy in order to make the diagnosis.