A classification of problems regarding gut endocrinomas (carcinoids and relevant neoplasms)

In the field of gut endocrinomas (carcinoids and relevant neoplasms), sever al classifications have been internationally accepted and utilized at varyi ng frequency. The basis of the concepts regarding gut endocrinomas from whi ch these classifications have been proposed were drawn from the different a spects. These included embryology, histologic growth patterns, histochemist ry including silver impregnations, electron microscopic morphology of endoc rine secretory granules, endocrine cell types and histologic morphology alo ng with functional characteristics, supplemented by immunohistochemical fea tures. Due to continuous progress being made in this particular field of re search and the many new discoveries made by pioneering investigators, the c oncepts of gut endocrinomas have been modified and revised during such long history of the research activities. This study aims to re-evaluate these classifications in relation to the con cepts of gut endocrinomas, and to select and supply rearranged classificati ons that may be easily utilized for practical purposes. This study also pro poses a comprehensive overview of histogenesis in the gut endocrinoma group . This consists of typical carcinoids and their atypical variants taken in relation to the carcinomatous group including ordinary carcinomas and their variants with endocrine elements. Special emphasis is given to the point t hat there is a gradual transition, one without a definite boundary between these tumors.