Pathologic observations of the duodenum in 615 consecutive duodenal specimens: I. benign lesions.

The author investigated histopathology of 615 consecutive duodenal specimens in our pathology laboratory. Computer search of the duodenal lesions was performed. Review of histological slides was done, when appropriate. The duodenal specimens were composed of 567 benign lesions and 48 malignant lesions. The 567 benign lesions were composed of chronic non-specific duodenitis in 334 cases (60.0%), duodenal ulcer in 101 cases (17,8%), heterotopic gastric mucosa in 81 cases (14.3%), hyperplastic polyp in 16 cases (2.8%), Brunner's gland hyperplasia in 14 cases (2.5%), Brunner's gland adenoma in 8 cases (1.4%), lymphoid polyp in 5 cases (0.8%), tubular adenoma in 4 cases (0.7%), lymphangioma in 2 cases (0.4%), endocrine nests in 1 case (0.2%), and amyloidosis in 1 case (0.2%). The chronic non-specific duodenitis was characterized by edema and lymphocytic infiltration. The duodenal ulcer was characterized by exudate, necrosis, granulation tissue and regenerative epithelium. The heterotopic gastric mucosa consisted of two types: one was composed of only foveolar epithelium (n=21) and another foveolar epithelium and fundic glands (n=60). Hyperplastic polyp was characterized by proliferation of gastric foveolar-like epithelium. The Brunner's gland hyperplasia was characterized by hyperplastic proliferation of the gland. The Brunner gland adenoma was characterized by neoplastic proliferation of the gland. The lymphoid polyp was characterized by large lymph follicles with large germinal centers. The tubular adenoma was characterized by adenomatous proliferation of intestinal epithelium, similar to colon adenoma. The lymphangioma was characterized by submucosal cavernous proliferation of lymphatics. The endocrine cell nests were characterized by non-neoplasmic proliferation of neuroendocrine cells. The amyloidosis was characterized by deposition of amorphous materials positive with Congo-red stain.