MSH: A benign epithelial tumor with a glandular organization.,CSP: benign epithelial tumor in which the cells form recognizable glandular structures or in which the cells are clearly derived from glandular epithelium.,NCI: A tumor that is not cancer. It starts in gland-like cells of the epithelial tissue (thin layer of tissue that covers organs, glands, and other structures within the body).,NCI: A benign neoplasm arising from epithelium.,NCI: A neoplasm arising from the epithelium. It may be encapsulated or non-encapsulated but non-invasive. The neoplastic epithelial cells may or may not display cellular atypia or dysplasia. In the gastrointestinal tract, when dysplasia becomes severe it is sometimes called carcinoma in situ. Representative examples are pituitary gland adenoma, follicular adenoma of the thyroid gland, and adenomas (or adenomatous polyps) of the gastrointestinal tract.