Gallbladder cancer in a high risk area: morphological features and spread patterns.

BACKGROUND/AIMS: Gallbladder carcinoma is one of the most frequent malignant tumors in Chile. The aim of this paper is to show our experiences in gallbladder carcinoma. METHODOLOGY: Six-hundred-sixty-nine cases of gallbladder carcinoma were included in this prospective study; 557 females (83.5%) and 112 males (16.5%). In 466 cases (70%), diagnosis was carried out in the cholecystectomy sample, 45 cases were partial cholecystectomies and 158 cases were metastases of gallbladder carcinoma. RESULTS: Ninety-eight per cent of the cases were adenocarcinomas, and in 85% of the cases gallstones were observed. Thirty-seven per cent of the primary tumors were macroscopically inapparent. One-hundred-thirty-one cases (29%) were early carcinomas and 323 cases (71%) were advanced carcinomas. A relationship between differentiation grade and infiltration level (p=0.0001) was observed. Lymph-node metastasis was found in 18.5%, 4.5% and 3.3% in the first, second and third lymph-node barriers respectively. Muscular tumors presented no lymph-node metastasis, while in serosal tumors lymph node metastasis reached 62% (p=0.04). Hepatic tumor infiltration was observed in 11%, 19% and 38% of muscular, subserosal and serosal tumors. CONCLUSIONS: The high frequency of inapparent carcinomas, gallstones and inflammatory changes of the vesicular wall are elements that make the pre-operative diagnosis of gallbladder carcinoma difficult. Differentiation grade and infiltration level are the most reliable prognostic factors in gallbladder carcinoma. Lymph-node metastasis or liver tumor infiltration are infrequent in early gallbladder carcinoma.