Successful Treatment of Aggressive Mature B-cell Lymphoma Mimicking Immune Thrombocytopenic Purpura.

A 55-year-old woman suffered from hemorrhagic tendency. She had severe thrombocytopenia without any hematological or coagulatory abnormalities, and a bone marrow examination revealed an increased number of megakaryocytes without any abnormal cells or blasts. No lymphadenopathy or hepatosplenomegaly was observed on computed tomography. She was initially diagnosed with immune thrombocytopenic purpura (ITP). None of the treatments administered for ITP produced a response. However, abnormal cells were eventually found during the third bone marrow examination. The pathological diagnosis was mature B-cell lymphoma. Rituximab-containing chemotherapy produced a marked increase in the patient's platelet count, and her lymphoma went into complete remission.