Abstract
Our paper describes morphological characteristics of surgically resected cases of gallbladder cancer. Gallbladder cancer showed unique wall invasion pattern, based on the thin gallbladder wall structures. The majority of gallbladder cancers were adenocarcinoma; well differentiated type in the mucosal components and moderately to poorly differentiated type in the invasive components. Gross types of advanced cancers were classified into three groups: papillary infiltrating type (mass-forming tumor mainly in mucosa), nodular infiltrating type (mass-forming tumor mainly in bile duct wall) and flat infiltrating type (infiltrating tumor without distinct mass). The majority (80%) of advanced cancer cases were nodular infiltrating type or flat infiltrating type. The advanced cancers (subserosa-invasive cancers) revealed frequent lymphatic permeation (80%), venous permeation (60%), neural invasion (50%, and lymph nodal metastasis (60%). Wall invasion patterns are categorized in to two group: infiltrative growth type (53%) and destructive growth type (47%). The destructive growth type were thought to be more aggressive, characterized by more frequent vascular invasion and higher cell proliferation.
