Digestive System Adenoma

**Semantic type:** Neoplastic Process

**Definition:** A sporadic or less frequently familial neoplasm that arises from the glandular epithelium of the gastrointestinal tract and liver. In the gastrointestinal tract, it manifests as a polypoid or flat circumscribed lesion. Morphologically, it is characterized by a proliferation of neoplastic glandular cells and is associated with dysplasia. Based on the growth pattern, it may be classified as tubular, villous, or tubulovillous. The dysplasia is classified as mild, moderate, or severe. The frequency of malignant transformation depends on the size of the lesion and the degree of dysplasia. Larger gastrointestinal tract adenomas with severe dysplastic changes carry a higher risk of progression to invasive adenocarcinoma. Gastrointestinal tract adenomas may present as solitary or multifocal lesions. In the liver, it arises from the hepatocytes. Grossly, it appears as a soft, round mass. Morphologically, the neoplastic cells resemble normal hepatocytes.

**Synonyms:** - GI System Adenoma - Gastrointestinal System Adenoma