Introduction:
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare myeloid malignancy with non-pruritic, violaceous, and papulo-nodular skin lesions, as well as the involvement of the bone marrow and lymph nodes. BPDCN is recognized as a distinct acute leukemia entity by the WHO’s 2016 classification of hematological neoplasms[1]. BPDCN is more common among the elderly, with a median age of 65 years, while in children, particularly infants are much rare[2]. Neoplastic cells in BPDCN are now thought to be derived from plasmacytoid dendritic cells, as marked by the co-expression of CD4 and CD56 without any lineage-specific markers other than plasmacytoid dendritic cell antigen-2 (BDCA-2, CD303) and interleukin-3 receptor a chain (CD123), which are markers for plasmacytoid dendritic cells, and the absence of features for B, T, myeloid or monocytic. The etiology and pathophysiology of BPDCN remain mostly unknown due to the scarcity of research reports to date.
Herein, we report a rare case of inherited BPDCN who had cutaneous and peripheral blood and bone marrow involvement and whole-exome sequencing suggesting the presence of a KMT2C gene duplication; the infant died rapidly after the parents abandoned treatment for the diagnosis.