Gastric sarcoidosis presenting as multiple, discolored mucosal lesions after Helicobacter pylori eradication.

The patient was a 71-year-old woman who was found to have multiple, yellowish, plaque-like lesions in the mucosa of the gastric greater curvature a long time after Helicobacter pylori eradication therapy. On magnified endoscopy, the lesions had indistinct boundaries with the surrounding non-atrophic mucosa, but irregularities of the surface microarchitecture or microvascular pattern were not observed. The differential diagnosis included early gastric adenocarcinomas of the fundic gland or poorly differentiated type, extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue, granulomatous disease, amyloidosis, and localized mucosal atrophy. Biopsy specimens taken from the lesions revealed multiple, non-caseating epithelioid cell granulomas in the mucosa. Schaumann bodies were observed in a few multinucleated giant cells within granulomas, and a few fine granules immunoreactive for Cutibacterium acnes (formerly Propionibacterium acnes) were observed in epithelioid cells. These findings confirmed the diagnosis of gastric sarcoidosis. Although serum angiotensin-converting enzyme level was slightly elevated, no sarcoid lesions of other organs were detected on radiological examinations. Interestingly, she was a carrier of human T-cell leukemia virus type 1 and also had a history of chronic hepatitis B. Activation of T lymphocytes in HTLV-1 infection concomitant with an age-related weakened immune system may have affected the clinical course of gastric sarcoidosis in this case.