Histopathological study using computer database of 10 000 consecutive gastric specimens: (1) benign conditions.

Using a computer database, the author investigated the histopathology of 10 000 consecutive gastric specimens, taken in the last 12 years (2002-2013) at the pathology laboratory of a Japanese hospital. Re-observation of the already examined histological sections was done when the histological diagnosis and findings on the computer data base were not very obvious. The gastric specimens were identified as 8579 benign conditions and 1421 malignant lesions. The 8579 benign conditions were comprised almost normal stomach in 74 cases (0.9%), chronic gastritis in 4374 (51.0%), benign gastric peptic ulcer in 2195 (25.6%), foveolar hyperplastic polyp in 1004 (11.7%), fundic gland polyp in 421 (4.9%), adenoma in 487 (5.6%), heterotopic pancreas in 9 (0.1%), pancreatic acinar metaplasia (PAM) in 8 (0.1%), and amyloidosis in 7 (0.1%). Chronic gastritis showed lymphocytic infiltration and frequently showed erosions and intestinal metaplasia. Gastric peptic ulcer showed exudate, necrosis, active inflammation, and regenerative atypia of the epithelium. Foveolar hyperplastic polyp revealed 23 malignant changes and frequently showed dysplastic glands and intestinal metaplasia. Fundic gland polyp demonstrated cystic dilations of fundic gland ducts. Gastric adenoma showed adenomatous proliferation in the superficial mucosa and cystic dilation of the epithelium under the adenoma. Heterotopic pancreas was located in the submucosa and consisted of acinar cells, ducts, and occasionally islets. PAM was a tiny lesion in the mucosa and consisted of only pancreatic acinar cells. Amyloidosis was primary amyloidosis with positive reaction with Congo-red stain.