A rare case of Blastic plasmacytoid dendritic cell neoplasm with gynecologic presentation.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy characterized by the proliferation of plasmacytoid dendritic cells with a blast-like appearance. It usually presents in elderly people, and clinical manifestations include nodular blue-violet skin lesions, bone marrow infiltration and, less frequently, extramedullary involvement. Gynecological manifestation (breast mass and exocervical lesion) is an unusual and rare presentation. Herein, we report the case of a 51-year-old woman patient who presented with a history of a rapidly growing and bleeding breast mass, along with a decline in general health. Notably, the disease had multifocal involvement, affecting the breast, uterine cervix, and cervical lymphadenopathy. Biopsies were performed on the breast mass and cervical lesion. Histopathological examination showed a diffuse lymphoid proliferation. The neoplastic cells show immunoreactivity for CD45 and CD56. The myelogram showed a 50 % excess of blasts with a heterogeneous appearance with the presence of cells that could suggest dendritic plasmacytoid cells. Bone marrow immunophenotyping showed the presence of blast-like cells that were positive for CD4, CD56, CD123, which supported the diagnosis of BPDCN. Despite initiating chemotherapy, the patient's condition rapidly deteriorated, highlighting the aggressive nature of BDCP. This case underscores the importance of early detection and the need for further research to improve outcomes for this rare condition.