Sarcoid-like reaction in the regional lymph nodes and spleen in gastric carcinoma: a clinicopathologic study of five cases.

To clarify the occurrence of sarcoid-like reaction in the spleen of the gastric carcinoma patients, 100 consecutive specimens from gastrosplenectomy were examined. Sarcoid-like reaction was observed in the lymph nodes of 13 cases (13%) and the spleen of five cases (5%). All cases of the latter group were included in the former one. None of them showed any symptoms or signs indicative of systemic sarcoidosis. It seems that the cases with sarcoid-like reaction in the spleen ocurred more frequently in an advanced stage of the gastric cancer than those without this phenomenon. Epithelioid cell granulomas (EPGs) appeared to arise in the periarteriolar lymphoid sheaths of the spleen histologically, but were never found in red pulp or germinal centers. They were composed of groups of epithelioid cells and accompanied by the small lymphocytes and plasma cells. In three cases, scattered eosinophils were also observed among the epithelioid cells. Immunohistochemically, the majority of the intragranulomatous small lymphocytes had T-cell phenotype, while B-cells formed only the minor cellular population. None of the 13 cases contained EPGs in the primary tumor. Our study indicates that sarcoid-like reaction in the spleen is possibly not such a rare phenomenon in the gastric cancer as previously considered and more frequently seen in the advanced stage of the gastric cancer. Sarcoid-like reactions of the regional lymph nodes were more frequently seen in the patients with EPGs in the spleen than in those without. We also suggest that the incidence of sarcoid-like reactions in the spleen is closely related to those in pancreaticosplenic nodes and/or nodes of the hilus of the spleen.