A Case of Primary Benign Histiocytosis X of the Stomach

To our knowledge, there are only six cases of histiocytosis X confined to the stomach. A rare case of gastric polyposis caused by infiltration of histiocytes is reported. A 35-year-old Korean woman with no particular complaints was found to have numerous polyps all over the gastric wall revealed by radiographic and endoscopic examination. Endoscopic biopsy of polyps showed that there were diffuse solid infiltration of hidstiocytes with indistinct cytoplasmic membrane and an absence of phagocytosis in laminar propria mucosae. Immunohistiochemical stain showed positive reaction for S-100 and CD68 and a negative reaction for cytokeratin in the infiltrating histiocytes. Electron microscopic examination showed foamy vacuoles with digested debris around nucleus and displaced cellular organelles to periphery. Systemic examination showed no abononnalities outside the stomach.