Extramedullary blast crisis in a patient with chronic myelogenous leukemiain complete cytogenetic and molecular remission on interferon-alpha therapy

We report the previously undescribed occurrence of extramedullary blast cri sis in a patient with chronic myelogenous leukemia in complete cytogenetic and molecular remission on interferon-cc. Development of bilateral testicul ar swelling prompted a biopsy showing stromal infiltration with CD20 and Td T positive immature cells. On repeated examinations, the bone marrow remain ed BCR/ABL negative by RT-PCR analysis. However, the cerebrospinal fluid (C SF) contained atypical lymphocytes positive for the P210 BCR-ABL product. F ollowing treatment with testicular irradiation, intrathecal methotrexate, s ystemic chemotherapy and an unrelated donor transplant, the patient showed no evidence of disease until 9 months post-transplant, when he relapsed in lymphoid blast crisis in both bone marrow and CSF. (C) 2000 Published by El sevier Science Ltd.