Morphometrical analysis of gall-bladder adenoma and adenocarcinoma with reference to histogenesis and adenoma-carcinoma sequence.

In order to examine whether our subdivision of gall-bladder adenoma and adenocarcinoma into non-metaplastic and metaplastic types is reasonable from the viewpoint of their cytological features, a morphometrical analysis was conducted on 17 adenomas and 59 adenocarcinomas. The morphometrical parameters used were nucleo-cytoplasmic ratio (N/C ratio) and nuclear areas (NA). N/C ratio in the metaplastic type of both adenoma and adenocarcinoma was significantly larger than that in the non-metaplastic. This result shows that the different tumour types are associated with a different N/C ratio. Continuous measurement of N/C ratio and NA in progressing from non-cancerous mucosa to the lesion was made and the data obtained were analysed by the Lowess method. In some adenomas the total area of polypoid lesions was serially measured and these data were also analysed by the Lowess method. The results showed different processes in non-metaplastic and metaplastic types of adenoma and adenocarcinoma from the standpoint of nuclear changes of N/C ratio and NA. These results indicate that our histogenetic classification of adenocarcinoma is reasonable in morphometrical nuclear analysis. We also investigated the adenoma-carcinoma sequence as a possible histogenesis for gall-bladder carcinoma. Eight (72.7%) of 11 metaplastic adenomas and two (33.3%) of six non-metaplastic adenomas had foci of atypical gland proliferation and were considered to be carcinomas. Moreover, these carcinomatous areas were surrounded by severe dysplasia. These findings indicate that adenoma-carcinoma sequence accounts for one of the histogenesis of gall-bladder carcinoma.