Ovarian cancer
Most ovarian cancer arises from fallopian tube or ovarian surface epithelium and spreads early across the capacious peritoneal cavity rather than via lymphatics, which is why it produces only vague abdominal symptoms and is usually advanced by the time it is diagnosed.
First principles
Many high-grade serous cancers begin in the fallopian tube, not the ovary
Contrary to the traditional teaching that ovarian cancer arises purely from ovarian surface epithelium, much high-grade serous carcinoma (the commonest and most lethal subtype) is now understood to originate in the fimbrial epithelium of the fallopian tube, later seeding the adjacent ovary. This matters clinically because it explains why the disease can be well established before any ovarian mass is large enough to detect.
Educational content pending clinical review. Not medical advice.