Peripheral T-cell lymphomas. Immunologic and enzyme histochemical analysis of 15 cases.

Fifteen cases of peripheral T-cell lymphoma were studied to evaluate the respective properties of various histologic types using enzyme histochemical and ultrastructural examinations in addition to immunological methods. Eleven cases in an ATLA-negative group manifested various histologic patterns such as IBL-like, pleomorphic and Lennert's lymphomas in comparison with the relatively monomorphic proliferation of neoplastic lymphoid cells in the 4 ATLA-positive cases. The presence of neoplastic clear cells is characteristic of peripheral T-cell malignancies, and is likely to be found in CD4+ lymphomas. There is an occasional reaction of epithelioid histiocytes and plasma cells with eosinophils, the former being designated Lennert's lymphoma and the latter IBL-like T-cell lymphoma. Immunological examination revealed four immunophenotypic patterns: (1) CD2+3+4+8-, (2) CD2+3-4+8-, (3) CD2+3+4-8+, and (4) CD2+3+4+8+, but did not provide information concerning the intimate relationship between histologic types and immuno-phenotypes. beta-Glucuronidase reactivity, however, contributed to the distinction between helper and suppressor T-cell malignancies, suggesting its usefulness for distinguishing these two cell types and their malignant counterparts.