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.