T-cell lymphomas in adults: a clinicopathological study of eighteen cases.

Eighteen cases of adult T-cell lymphoma have been studied with respect to clinical presentation, response to treatment, histology, enzyme histochemistry, immunocytochemistry, and gene rearrangement. Seven cases (39 per cent) presented at extra-nodal sites, and the age range was from 18 to 79. Treatment was with combination chemotherapy in most cases, and 11 of the 18 patients died within the three year follow-up period. The lymphomas were classified morphologically into six types; T-lymphoblastic lymphoma (TLL), angioimmunoblastic lymphadenopathy (AIL)-like T-cell lymphoma, T-zone lymphoma, pleomorphic mixed medium and large cell T-cell lymphoma (PMMLC), pleomorphic large cell T-cell lymphoma (PLC), and monomorphic large cell T-cell lymphoma (MLC). Enzyme histochemistry was found to be of limited value in the identification of T-cell lymphomas. Immunocytochemistry showed a degree of correlation between the immunological profile and morphology, with cases in the PLC and MLC groups showing limited expression of T-cell antigens. Re-arrangement of the beta chain of the T-cell receptor gene was detected in 12 of the 14 cases studied, and all showed germ-line immunoglobulin genes. The study emphasizes the varied morphological and clinical appearances of adult T-cell lymphoma.