Gallbladder Mucinous Cystic Neoplasm, High Grade

**Semantic type:** Neoplastic Process

**Definition:** A non-invasive neoplasm that arises from the gallbladder and is characterized by the presence of neoplastic columnar mucin-producing epithelial cells that form papillae with irregular branching and budding, cystic changes, underlying ovarian-type stroma, and severe dysplasia. Mitotic activity is present and the mitoses may be atypical.

**Synonyms:** - Gallbladder MCN with High Grade Intraepithelial Neoplasia - Gallbladder Mucinous Cystic Neoplasm with High Grade Intraepithelial Neoplasia - Gallbladder Mucinous Cystic Neoplasm, High-Grade