Placental protein 10: levels in benign and malignant ovarian cyst fluids and pleural exudates.

Placental protein 10 (PP10) was measured in benign (n = 47) and malignant (n = 10) ovarian cyst fluids and in pleural fluid specimens from 19 patients with pleural metastases of various carcinomas (n = 15) or infectious pleurisy (n = 4). PP10 was found in 9 out of 18 follicular or luteal cyst fluids (range 2.0-42.0 micrograms/l) and in 24 out of 29 benign ovarian tumours (range 2.6-38.0 micrograms/l). Nine out of ten malignant ovarian cyst fluids contained detectable PP10 (range 4.0-55.2 micrograms/l). PP10 was found in all the pleural fluids from 15 patients with metastatic bronchial, pulmonary, breast or pancreatic carcinomas (range 5.1-100.2 micrograms/l), as well as from four patients with pleurisy (range 5.0-28.6 micrograms/l). Our results indicate that PP10 is tumour-associated, but not tumour-specific.