Clinical, hematologic, and pathologic features of leukemic T-cell lymphoma.

Cells obtained from malignant lymph nodes and the peripheral blood of 106 patients with non-Hodgkin's lymphomas were examined for T- and B-cell characteristics. Surprisingly, 79 cases were of the T-cell type on the basis of spontaneous rosette formation with sheep erythrocytes (E-rosettes). Of the remaining cases, 15 were B-cell in nature (monoclonal S-Ig positive), seven were non T-, non B-cell and four cases were undetermined. Forty-nine (62.0%) of the T-cell malignancies were of a leukemic variety, characterized by pleomorphism in the peripheral blood cell size, and histological appearance. Most of the leukemic T-cells showed obvious lymphocytic differentiation, with condensed nuclear chromatin and scant cytoplasm, although in many of the cases, the lymphomatous infiltrate was dominated by large or pleomorphic lymphoid cells. All tumors were of a diffuse variety, and on histologic examination included a mixed type (21 cases), PDLL forms (15 cases), a large lymphoid cell type (eight cases), and WDLL forms (five cases). Although the mixed type with a pleomorphic lymphoid infiltrate was distinctive, there has been considerable variation from case to case. Clinically this unusual t-cell, leukemic variety of non-Hodgkin's lymphomas primarily involved middle-aged and elderly subjects, and was characterized by wide spread organ invasion (preferentially to the liver, spleen and skin), resistance to chemotherapy, and a poor prognosis. A mediastinal mass was not observed in all cases. The patients had a median survival of only ten months.