IMMUNOHISTOCHEMICAL LOCALIZATION OF PREGNANCY-RELATED PLACENTAL PROTEIN-4 IN NONTUMOROUS TISSUES AND IN GYNECOLOGICAL TUMORS

The aim of the study was to demonstrate the localization of placental protein 4 (PP4) in different nontumorous and tumorous tissues originat ing from the female genital tract. PP4 immunoreactivity was demonstrat ed using the peroxidase-antiperoxidase immunohistochemical technique. Tissue samples were obtained from the cervix and body of the uterus, o vary, vulva and from gestational trophoblastic tumors. PP4-positive ce lls were present in nontumorous tissues with various pathologic findin gs, and in many but not all benign gynecological tumors. Similar numbe rs of PP4-positive cells were located in malignant and benign gynecolo gical tumors; however, PP4 staining intensity was greater in the malig nant lesions. PP4-positive cells were found in hydatidiform moles and in choriocarcinoma. PP4 was distributed mainly in the cytoplasm, but i t was also bound to the cell membrane. We conclude from these studies that PP4 is located in a variety of benign and malignant cells of the female genital tract and that these cells may be the source of plasma PP4 found in patients with these conditions.