PRIMARY GASTRIC T-CELL LYMPHOMA OF SUPPRESSOR-CYTOTOXIC (CD8+) PHENOTYPE - DISCORDANT EXPRESSION OF T-CELL RECEPTOR SUBUNIT-BETA-F1, CD7, AND CD3 ANTIGENS

Primary gastric T-cell lymphomas are rare neoplasms, and all but one of the previously phenotyped cases have shown a helper-inducer phenotype. The present case is the second reported case of a primary gastric T-cell lymphoma of suppressor-cytotoxic phenotype. The tumor histology was similar to that described in some forms of node-based peripheral T-cell lymphomas. Phenotypic analysis revealed low expression of pan-T marker CD7, reduced expression of CD3, but higher density and frequency of expression of CD8 antigens that could be predicted on the basis of the pan-T markers. Natural killer cell (NK) related markers CD16, HNK-1 and NKH-1 were not expressed by the neoplastic cells. T-cell receptor (TCR) β subunit expression was detected on fewer cells than would have been predicted on the basis of CD3 and CD8 expression, and TCR δ chain expression was undetectable. © 1990.