Neurohormonal peptides in ovarian carcinoids: an immunohistochemical study of 81 primary carcinoids and of intraovarian metastases from six mid-gut carcinoids.

Eighty-one primary ovarian carcinoids and intraovarian metastases from six mid-gut carcinoids were examined for the presence of tumor cells immunoreactive with antisera raised against various neurohormonal peptides, mostly of gastroenteropancreatic (GEP) origin. Twenty of the primary and two of the metastatic carcinoids contained such tumor cells. The incidence of tumors with any kind of neurohormonal peptide immunoreactive tumor cells was 53% in the trabecular carcinoids, and 42% in the strumal carcinoids, whereas the incidence was much lower (7%) in the insular type. Immunoreactive pancreatic polypeptide (PP), glucagon, enkephalin, and somatostatin were those neurohormonal peptides most commonly observed in the tumor cells of the primary carcinoids. Those less commonly found were substance P, calcitonin, VIP, neurotensin, beta-endorphin, and ACTH. Four metastatic carcinoids were nonreactive with all the antisera used. Cells storing immunoreactive insulin, glucagon, PP, VIP, gastrin, substance P, or enkephalin were found in one of the two remaining metastatic carcinoids; in the other only gastrin-immunoreactive tumor cells were observed. The occurrence and distribution of tumor cells storing the neurohormonal peptides in ovarian carcinoids are discussed in relation to their possible origin in the ovary and to carcinoids in the gut.