Carcinoma in situ of the gallbladder. A clinicopathologic study of 18 cases.

Eighteen cases of carcinoma in situ of the gallbladder collected over a 7-year period at the General Hospital of Mexico City are reported. All patients were females whose ages ranged from 26 to 83 years with a mean of 55. Their symptoms and signs were related to the presence of stones. Grossly, the in situ carcinomas could not be differentiated from chronic cholecystitis. In only one case was the diagnosis suspected on macroscopic examination. Thirteen lesions were located either in the fundus or body of the gallbladder. Histologically there were two types of in situ carcinoma--papillary (two cases) and nonpapillary (16 cases). Hyperplasia of the antral-type glands was associated with 12 cases and cholecystitis follicularis with four. The atypical changes began on the surface epithelium and extended into the epithelial invaginations and later into the antral-type glands. Four carcinomas in situ exhibited limited invasion into the underlying lamina propria or inner part of the muscle layer. In the 15 cases that were examined, immunoperoxidase stains revealed cytoplasmic staining for carcinoembryonic antigen (CEA). All patients we were able to follow (those who had only carcinoma in situ) are symptom-free after cholecystectomy. One of the four patients with microinvasion died 7 years after cholecystectomy with clinical evidence of liver metastasis.