Blastic Plasmacytoid Dendritic Cell Neoplasm: A Rare Case Report

The rare haematologic malignancy dubbed blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a pathological condition characterised by the proliferation of immature plasmacytoid dendritic cells, typically presenting with cutaneous lesions and systemic symptoms that incidentally present an aggressive clinical course. A 68-year-old male presented with erythematous skin nodules characterised by a proliferation of immature plasmacytoid dendritic cells, and consistent with a diagnosis of BPDCN. Histological examination of skin biopsy revealed a neoplasm composed of a monomorphous population of cells co-expressing cluster of differentiation (CD) CD123, CD56 and focal CD4, further confirming the BPDCN diagnosis. Bone marrow evaluation showed no significant involvement. Initial treatment with steroids led to partial regression of skin lesions, but recurrence necessitated chemotherapy using a modified Mitoxantrone, Chlorambucil, Prednisolone (MCP) 841 regimen, which led to significant clinical improvement initially. This case accentuates the diagnostic value and critical role of immunohistochemistry in diagnosing BPDCN. Early diagnosis and initiation of therapy are critical in prognosis, and emerging targeted therapies offer new hope in the treatment of this disease.