Gastric lymphoreticular neoplasms: an immunologic study of 36 cases.

Thirty-six lymphoreticular neoplasms involving the stomach were studied by immunologic technics (particularly immunoperoxidase on paraffin sections) for the localization of immunoglobulins, lysozyme, and alpha one-antitrypsin. Fifteen of 29 (52%) primary gastric lymphomas marked as B-cell lymphomas and only one primary gastric lymphoma of true histiocytic type was identified. This is in contrast to the high incidence of true histiocytic tumors reported in some recent studies. Immunoperoxidase on paraffin-embedded and frozen tissues from endoscopic biopsies or surgical resections was particularly useful in confirming the diagnosis of five of seven B-cell immunoblastic sarcomas and 8 of 12 small lymphoid proliferations including two pseudolymphomas. Twenty-two of 29 (76%) primary gastric lymphomas were large-cell lymphomas. The previously reported high incidence of plasma cell tumors could not be confirmed. Atrophic gastritis remote from the neoplasm was noted in 8 of 15 (53%) patients, and this relationship is discussed.