Histogenetic Relationship Between Carcinoids and Mucin-secreting Carcinomas of Colon as Revealed by Heterotransplantation

Heterotransplantation of a human colonic neoplasm with classical morphologic characteristics of a carcinoid was sucessful in the cheek pouches of unconditioned, adult golden hamsters after a short sojourn in cell-impermeable chambers in rats. Although no mucin-secreting cells were detected in the donor carcinoid, the cheek pouch transplants exclusively exhibited mucinsecreting tumour cells of signet-ring type consistent with adenocarcinoma. This transplantable tumour, designated GW-77, has retained this appearance as well as expansive growth characteristics in xenogeneic hosts for a period of 4 years. These findings represent strong biological evidence consonant with views, based upon morphological findings, advocating a histogenetic relationship between colonic carcinoid and adenocarcinoma. It is believed that colonic adenocarcinoma has a selective advantage over carcinoid for serial propagation in an alien environment, indicating the less differentiated nature of its cellular components. Since the donor carcinoid cells failed to exhibit argentaffin reactions, these conclusions may be limited only to the nonreactive forms of carcinoid. IMAGES: