Idiopathic granulomatous gastritis resembling a gastrointestinal stromal tumor.

A 41-year-old female presented with a 2 cm gastric submucosal tumor that was suspected to be a gastrointestinal stromal tumor or other malignancy, and local resection of the stomach was performed. However, histopathological examination showed granulomatous gastritis (GG) with a variety of chronic inflammatory cells and multinodular granulomas. Although she had a past history of tuberculosis and advanced breast cancer after surgery, there was no apparent evidence of either tuberculosis or a metastatic tumor. Other causes of GG, such as mycosis, syphilis, sarcoidosis or foreign body reaction were also excluded. There were no clinical features of Crohn's disease as the principal differential diagnosis. Therefore, she was diagnosed to have idiopathic granulomatous gastritis (IGG). IGG is rare with few reports, and this report presents a surgical case of IGG resembling a gastrointestinal stromal tumor.