PRIMARY MESENTERIC TUMOR OF ADULT T-CELL LEUKEMIA-LYMPHOMA - REPORT OF A CASE

A rare case of primary mesenteric tumor of adult T-cell leukemia/lymph oma (ATLL) is reported. A 64-year-old man was admitted to our hospital after the diagnosis of a palpable ileocecal tumor. Although the serol ogic test for human T-cell lymphotrophic virus type I (HTLV-I) antibod y was positive, neither ATLL cells in the peripheral blood nor systemi c lymphadenopathy were observed. At laparotomy, the tumor was histopat hologically revealed to be ATLL, and was also found to be restricted t o the mesentery. An immunohistochemical examination of the tumor tissu e using a specific monoclonal antibody was positive for CD2 and CD4, a nd negative for CD8. Proviral genome integration in the tumor cells wa s found by Southern blotting using a P-32-labeled HTLV-I probe with Ec oRI and PstI digestion. Combination chemotherapy including cyclophosph amide, Adriamycin, vincristine, and prednisolone was begun postoperati vely, but the patient did not respond to therapy. Up to now, only two cases of ATLL originating primarily in the abdominal cavity have been reported. These cases all demonstrate the need to consider the possibi lity of a primary ATLL mesenteric tumor without leukemic manifestation in the peripheral blood.