title: Sessile adenoma of the gallbladder. Reappraisal of its importance as a precancerous lesion.
abstract: Three hundred gallbladders from patients with cholelithiasis were examined under a dissection microscope. Sixteen (5%) were found to have what have been called sessile adenomas. They consisted of mixtures of hyperplastic lining epithelium and metaplastic mucous glands, and their interstitium often included smooth-muscle fibers. Small foci of moderately severe cellular atypism were present in 19% of the adenoma cases, but none had definitive evidence of malignancy. Carcinoembryonic antigen was demonstrated in hyperplastic lining epithelium with or without cellular atypism in 31% of the cases. Sessile adenomas most likely represent reactive overgrowth and therefore we prefer to term them hyperplastic polyps.
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D002769:Cholelithiasis / Q000378:metabolism / Q000473:pathology; D005706:Gallbladder Neoplasms / Q000378:metabolism / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D006965:Hyperplasia; D007124:Immunoenzyme Techniques; D008679:Metaplasia / Q000473:pathology; D008875:Middle Aged; D011230:Precancerous Conditions