[Adult T-cell leukemia with cervical bone tumor showing immunophenotypic change]

A 60-year-old man born in Miyazaki prefecture was admitted to our hospital complaining of skin rash in December 1989. On hematological examinations, leukocyte count was 14,200/microliters with 49% of abnormal lymphocytes showing lobulated nuclei. The surface marker study revealed their phenotype as CD4+8-. Anti human T cell leukemia virus type I (HTLV-I) antibody and monoclonal integration of proviral DNA were positive. From the above results, he was diagnosed as adult T-cell leukemia (ATL). Abnormal lymphocytes gradually decreased without treatment after the first admission. In January, 1990, he began to complain of neck pain. Two months later he was readmitted because of paresis of extremities and disturbance of urination. Vertebral bone mass and a compressed spinal cord in the 4th cervic level were confirmed by MR imaging. He received a resection of tumor and an anterior fusion of vertebrae. The bone tumor was histologically diagnosed as malignant lymphoma, diffuse medium-size cell type and the infiltrating cells had their phenotype as CD4+8+. He was postoperatively treated with combination chemotherapies, but neurological abnormalities did not improve. He died of pneumonia on 35 days after the operation. A postmortem examination revealed extradural tumor formation with ATL cells. This case is considered to be rare in respect of both the disappearance of most peripheral abnormal lymphocytes without any treatments and the cervical bone tumor showing immunophenotypic change.