Carcinoma of the gallbladder: the correlation between histogenesis and prognosis.

Ninety-two cases of adenocarcinoma of the gallbladder were classified into the metaplastic or non-metaplastic type, based on the presence or absence of metaplastic changes in the tumour tissues. The differences in biological characteristics were compared between these tumour types. The metaplastic type was more common than the non-metaplastic type in females and the survival rate in this type was better than that in the non-metaplastic type. The modes of tumour spread also differed, the metaplastic type frequently showed lymphatic metastasis, whereas the non-metaplastic type often metastasized by direct invasion. The difference in prognosis might be explained by the different modes of tumour spread. This classification corresponded well to that of gastric carcinoma into intestinal type and diffuse type and the results suggest that it might provide a basis for evaluating various aspects of gallbladder carcinoma.