A rare case of acute leukemic presentation of blastic plasmacytoid dendritic cell neoplasm without cutaneous lesions

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy with a clinically aggressive phenotype arising from CD4/CD56-expressing plasmacytoid dendritic cell precursors [1]. BPDCN was categorized under "AML and related precursor neoplasms" by the 2008 WHO classification, with most cases having been previously classified as blastic natural killer (NK)-cell lymphoma/leukemia or agranular CD4+, CD56+ hematodermic neoplasm [2]. BPDCN cells generally express CD4, CD56, CD123, and TCL-1 but are negative for other T-, B-, NK-cell, or myeloid markers [3]. Clinically, patients with this disease typically present with a high incidence of cutaneous involvement described as generalized, localized, or solitary macules, plaques, and/or tumors, as the first manifestation, followed by involvement of bone marrow (BM), peripheral blood (PB), and lymph nodes (LNs). BM involvement usually occurs with leukemic progression of advanced or relapsed disease and is associated with a poor prognosis [4]. Diagnosis of leukemic BPDCN without cutaneous manifestation is rare. Here, we report a 41-yr-old man who was diagnosed with BPDCN in the absence of skin manifestation.