Immunohistochemical demonstration of pancreatic secretory trypsin inhibitor in gynecologic tumors.

Pancreatic secretory trypsin inhibitor (PSTI) is a specific trypsin inhibitor secreted by the acinar cells of the pancreas. Serum levels of immunoreactive PSTI have been reported elevated in patients with various malignancies including gynecologic tumors. The immunohistochemical localization of PSTI is studied in the comparison with argyrophilia and amylase immunoreactivity on 100 ovarian tumors, 35 endometrial carcinomas, and 34 cervical carcinomas. PSTI was noted in 19 of 85 common epithelial tumors of the ovary, being most frequently in mucinous tumors and less in endometrioid, but only occurred in immature pancreatic tissue of 1 of 15 germ cell tumors tested. In the uterus, 5 of 19 adenocarcinomas of the endometrium and 3 of 10 adenocarcinomas of the cervix were positive for PSTI immunoreactivity. PSTI was found more frequently in the tumors with argyrophil cells, especially of type I, but was related to the intestinal metaplasia and exocrine secretion rather than argyrophilia itself, judging from the different localization of PSTI and argyrophilic granules. No relationship was observed between amylase and PSTI immunoreactivity.