Fallopian tube
Most people with epithelial ovarian carcinoma, about two-thirds, have a serous carcinoma, though this proportion is estimated as high as 80%. Low-grade serous carcinoma is less aggressive than high-grade serous carcinomas, though it does not typically respond well to chemotherapy or hormonal treatments. Serous carcinomas are thought to begin in the Fallopian tube. Histologically, serous adenocarcinomas have psammoma bodies. Low-grade serous adenocarcinomas resemble Fallopian tube epithelium, whereas high-grade serous adenocarcinomas show anaplasia and nuclear atypia.