Blastic Plasmacytoid Dendritic Cell Neoplasm: A Case Report and Clinicopathological Review

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is aggressive hematopoietic malignancy derived from the precursors of plasmacytoid dendritic cells. The present study reported a case of a 35-year-old BPDCN patient, who presented with scalp lesions without extracutaneous involvement of the lymph nodes (LNs), peripheral or bone marrow. Histopathological examination of scalp lesion revealed monomorphous diffuse infiltrate of small to medium-sized cells with irregular nuclear contours, pleomorphic nuclei, finely dispersed chromatin, inconspicuous nucleoli and scant amount of cytoplasm. Immunohistochemical staining showed diffuse positivity for CD45, CD4, CD 56, CD45 and negative for CD3, CD5, CD7, CD8, CD19, CD20, CD30, CD33, CD34, CD79a, CD99, CD117, TDT, and myeloperoxidase. Patient started treatment with acute lymphoblastic lymphoma protocol (Hyper-CVAD). Reevaluation after the second course showed marked regression of scalp lesion. The patient continued Hyper-CVAD protocol and planned for allogeneic stem cell transplant.