IMMUNOCYTOCHEMICAL DEMONSTRATION OF ENKEPHALIN AND β‐ENDORPHIN IN ENDOCRINE TUMORS OF THE RECTUM

Abstract

In a histopathological and immunocytochemical study of biopsy and/or operation specimens from 27 patients with endocrine tumors of the color and rectum (hind-gut carcinoids), enkephalin-immunoreactive tumor cells were observed in 2 cases. Both patients were obese women, about 50 yr of age, with a history of constipation. The tumors were situated near the anus in the dorsal wall of the rectum. One tumor had metastasized to a lymph node and the other showed vascular invasion. The tumor cells were non-argentaffin; some were argyrophil. One tumor contained only a few enkephalin-immunoreactive cells but had numerous .beta.-endorphin-immunoreactive cells, which were distinct from the former. The other contained large numbers of enkephalin-immunoreactive cells but no .beta.-endorphin cells. Both tumors also harbored glucagon-immunoreactive cells; in 1 there were also cells containing immunoreactive pancreatic polypeptide. These cells were distinct from the enkephalin-storing ones. No 5-hydroxytryptamine could be detected.