Cancer occurs when cells in an area of the body grow in an abnormal way. Primary peritoneal cancer (PPC) is a relatively rare cancer that develops most commonly in women. PPC is a close relative of epithelial ovarian cancer, which is the most common type of malignancy that affects the ovaries. The cause of primary peritoneal cancer is unknown.
It is important for women to know that it is possible to have primary peritoneal cancer even if their ovaries have been removed.
The abdominal cavity and the entire surface of all the organs in the abdomen are covered in a cellophane-like, glistening, moist sheet of tissue called the peritoneum. It not only protects the abdominal organs, it also supports and prevents them from sticking to each other and allows them to move smoothly within the abdomen. The cells of the peritoneal lining develop from the same type of cell that lines the surface of the ovary and fallopian tube for that matter. Certain cells in the peritoneum can undergo transformation into cancerous cells, and when this occurs, the result is primary peritoneal cancer. It can occur anywhere in the abdominal cavity and affect the surface of any organ contained within it. It differs from ovarian cancer because the ovaries in PPC are usually only minimally affected with cancer.
Fallopian Tube Cancer
The fallopian tubes are a pair of floppy tube like structures that originate at the top (fundus) of the uterus where they communicate with the endometrial cavity and course away from the uterus, on either side, towards the ovaries where they “flop” over the ovaries with their finger-like (fimbriated) end. Cancers of the fallopian tube are also relatively rare and very closely related to cancers of the ovary and PPC. They share many commonalities and emerging data is even suggesting that many of the previously felt to be ovarian cancers may indeed have been FTC.
Although the clinical presentation of FTC is very similar to ovarian cancer and PPC, there are some differences. Cancers of the fallopian tube arise within the inside (lumen) of the fallopian tube and typically cause it to swell like a sausage. The involvement of the ovary is secondary, but it is usually so extensive that one cannot tell whether it began on the ovary and spread to the fallopian tube, or vice versa. Because of that, many fallopian tube cancers may have been classified as ovarian cancers. As the fallopian tube swells with cancer, it produces fluid, similar to ascites, that can “leak” back into the uterus and lead to a watery vaginal discharge, the classic presentation of FTC when associated with an adnexal mass.
The Foundation for Women’s Cancer offers educational materials that explore this in more depth.