Bilateral conjunctival lesions in blastic plasmacytoid dendritic cell neoplasm

The purpose of this study is to report on a patient who developed conjunctival lesions of blastic plasmacytoid dendritic cell neoplasm (BPDCN) after radiation to skin lesions of the same pathological type. A 79-year-old man developed salmon-pink lesions in the lower fornix of the conjunctiva of both eyes and biopsy revealed BPDCN. One and a half years previously, he noticed an erythematous plaque with a 30-mm diameter, which later became multiple, on the left chest, and the biopsy revealed BPDCN. The bone marrow was negative for CD56-positive cells, but fluorescence-activated cell sorting analysis of peripheral blood cells revealed a group of cells positive for CD4 and CD56, or CD4 and CD123. The monocyte fraction, in an increased percentage of white blood cell counts, did contain atypical cells positive for the three markers. Whole-body 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography demonstrated no abnormal uptake lesions. He received 30 Gy of radiation to the chest lesions, and later, the same dose of radiation to novel skin lesions on the back, waist, and chest, and also to pharyngeal lesions. In conclusion, the conjunctiva could be involved with BPDCN and pathological differential diagnosis by biopsy is mandatory to establish the correct diagnosis.