Systemic organ invasion accompanied by immunophenotypic change observed in extraosseous plasmacytoma

We report a 57-year-old man who was diagnosed based on morphological findings as having extraosseous plasmacytoma of the left lower eyelid. Tumor cells were positive not only for CD38 and CD138, but also for CD19 and surface immunoglobulin lambda chain. He obtained a complete remission with irradiation and VAD therapy, but the disease relapsed one year later in the testis and popliteal fossa. Because tumor cells appeared to be blastoid, CHOP therapy was administered, and the patient achieved a temporary remission. Cytoplasmic lambda chain-positive and CD19-negative tumors eventually recurred at multiple sites including the central nervous system but not in the bone marrow. Treatment with the BD regimen and lenalidomide failed, and he died four years after the initial diagnosis.