Blastic Plasmacytoid Dendritic Cell Neoplasm: A Review of Diagnosis, Pathology, and Therapy

Abstract

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare malignancy of dendritic cell precursors classified as a subset of acute myeloid leukemia according to WHO. It commonly presents with dermal infiltration of plasmatoid dendritic cells that have the morphologic appearance of medium-sized blasts with irregular nuclei, faint chromatin, at least one nucleolus per cell and scant cytoplasm, expressing a CD4+CD56+CD123+lin- immunophenotype. Patients typically have discoloured cutaneous lesions that grow in size, and the diagnosis of BPDCN is confirmed on skin biopsy showing the characteristic cells. Bone marrow involvement is a common feature of this neoplasm and is found in most patients at diagnosis. There is no consensus on the most appropriate treatment for BPDCN, with the neoplasm showing initial good response to high intensity chemotherapy but inevitable relapse into a more chemotherapy-resistant disease. Hematopoietic stem cell transplant in patients who achieve their first complete remission with chemotherapy is a promising therapeutic modality requiring a prospective clinical trial to evaluate its efficacy.