Benign serous tumors are called serous cystadenomas, and are the most common type, and often develop on both ovaries, and typically affect premenopausal women.
The high levels of urea irritate the serous pericardium, making it secrete a thick pericardial fluid that's full of fibrin strands and white blood cells.
On the other hand, neoplastic cysts include endometriomas, serous and mucinous cystadenomas, and mature cystic teratomas, as well as malignant ovarian tumors.