[Pathologic study of precancerous lesion of the gallbladder].

Precancerous lesions of the gallbladder in 150 consecutive cholecystectomy specimens resected from the patients with cholelithiasis or cholecystitis are studied. Of these specimens, 80% had simple epithelial hyperplasia, 16% atypical hyperplasia, 1.3% carcinoma in situ and 2.7% invasive carcinoma. Atypical hyperplasia was observed in the mucosa adjacent to carcinoma in situ which, in turn, was found in the mucosa adjacent to invasive carcinoma. This finding suggests that some of simple hyperplasia of the gallbladder evolve towards atypical hyperplasia, carcinoma in situ which finally becomes invasive carcinoma. In addition, the authors put forward a morphologic criteria for grading the atypical hyperplasia of the gallbladder.