A combined morphologic and immunologic approach to the diagnosis of gastrointestinal lymphomas. I. Malignant lymphoma of the stomach (a clinicopathologic study of 22 cases)

Abstract

Twenty‐two cases of primary gastric non‐Hodgkin's lymphoma, which occurred over a 20‐year period, were reviewed. Eighteen tumors were studied using an immunoperoxidase method, and the presence of intracytoplasmic monoclonal immunoglobulin (Ig) in nine (50%) suggested a B‐cell origin. Four tumors (22%) contained intracytoplasmic muramidase (lysozyme), suggesting a true histiocytic origin. Five tumors (28%) did not contain immunoglobulin or muramidase. The muramidase‐positive “true histiocytic lymphoma” could not be differentiated from histiocytic lymphoma of lymphocytic origin using light microscopic examination alone. The patients with B‐cell lymphoma survived significantly longer than patients in the other two groups. The differentiation between true histiocytic lymphoma and other conditions is discussed.