Adult T-cell leukemia/lymphoma in which the pathohistological diagnosis was identical to that of Ki-1 positive anaplastic large cell lymphoma

A 65-year-old man developed severe lumbago and a loss of appetite two month s before presentation. A computerized tomograph at admission revealed soft tissue masses destroying the Th12, L4 and L5 vertebral bones. We diagnosed the lesions to be metastatic bone tumors, but the primary focus could not b e determined. Just after the irradiation treatment, abnormal lymphocytes we re detected in the peripheral blood cells, Under the suspicion of adult T-c ell leukemia/lymphoma (ATL), we thus performed a lymph node biopsy. The spe cimens were histologically composed of Ki-1 positive anaplastic large cell lymphoma (ALCL), The lymphoma cells demonstrated a biclonal integration of HTLV-1 proviral DNA. After 6 cycles of chemotherapy, the patient has demons trated a partial and favorable remission from ATL.