Atypical presentation of blastic plasmacytoid dendritic cell neoplasm: A potential diagnostic pitfall in nasal cavity

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare disease with an aggressive clinical course resulting in median survival times of 12 to 14 months.¹ It represents approximately 0.8% of primary cutaneous lymphomas.² According to the World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissue, published in 2008, BPDCN is defined as an acute myeloid leukemia related precursor neoplasm, derived from precursors of the plasmacytoid dendritic cell. It is characterized microscopically by its dense monomorphous infiltrates of medium-sized blastoid morphology and expression of CD4 and CD56, as well as the absence of any common myeloid, T-lymphoid, B-lymphoid, and natural killer-lymphoid lineage markers.³ A few series of BPDCN have been reported in the literature, but very few cases of BPDCN have been described with lack of skin manifestation at the time of diagnosis.⁴ Here, we report a rare case of BPDCN in the nasal cavity.