[Morphological study of carcinoma of the gallbladder: its differences between calculous and acalculous carcinoma].

The most characteristic phenomenon in patients with carcinoma of the gallbladder is frequent coexistence of gallstones. In this study, morphological differences of carcinoma of the gallbladder in between calculous and acalculous cases is investigated. This study involved fifty-three cases (eleven early carcinoma and forty-two advanced) that had been surgically treated at the Hamamatsu Medical Center Hospital during the past ten years. Nine of 11 early carcinomas were calculous and two, acalculous. All calculous carcinomas showed grossly superficial type and two acalculous, polypoid type. All of them were histologically differentiated adenocarcinoma. In advanced carcinoma, thirty-one of 42 cases were calculous and eleven, acalculous. Fifteen of 31 calculous cases showed polypoid type and sixteen, diffuse infiltrative type. In all cases with the latter type, the cystic duct was completely obstructed by impacted gallstones. All calculous carcinomas were histologically belonged to differentiated adenocarcinoma, mucinous carcinoma or adenosquamous carcinoma. On the other hand, six of 11 acalculous carcinomas revealed grossly polypoid type, and histologically differentiated adenocarcinoma or mucinous carcinoma. The remaining five were of diffuse infiltrative type, and of poorly-differentiated adenocarcinoma or signet-ring cell carcinoma. From these data, it may be highly suggestive that differentiated adenocarcinoma or adenosquamous carcinoma of histologic type irrespective of it's gross type is characteristic of calculous carcinoma, and poorly-differentiated adenocarcinoma or signet-ring cell carcinoma possessing primary diffuse infiltrative growth, of acalculous. The majority of the superficial type in early carcinoma and the diffuse infiltrative type in advanced are considered as a secondary modified gross appearance by direct or indirect effects of coexistent gallstones onto the main tumor.