Atraumatic splenic ruptures triggered both remission and death in a single case of blastic plasmacytoid dendritic cell neoplasm

[TO THE EDITOR] A 78-year-old Japanese man presented to our hospital with multiple skin lesions, multiple lymphadenopathies and moderate splenomegaly. Hematological examination revealed a white blood cell (WBC) count of 13100/μL with 63% blasts, hemoglobin concentration of 12.2 g/dL and platelet count of 42000/μL. Blasts in the peripheral blood were medium in size and had scant grey-blue cytoplasm. On flow cytometry analysis of peripheral blood, abnormal cells expressing CD2, CD4, CD7 and CD56 were observed. Based on these findings, we suspected leukemic transformation of lymphoma. Lymph node biopsy was performed and the specimen exhibited diffuse proliferation of large blastic cells. These cells were positive for CD4, CD56, CD123 and TCL1 on immunohisto-chemistry. Infiltration of these abnormal cells was also noted in the specimen from the skin lesion biopsy and bone marrow. The chromosomal analysis demonstrated a normal karyotype. Taken together, a diagnosis of blastic plasmacytoid dendritic cell neoplasm (BPDCN) was established. Fourteen days after the first visit, he returned with fever, anemia and tenderness in the left upper quadrant. We assumed progression of the disease and planned chemotherapy.