A paratubal cyst is a noncancerous (benign) fluid-filled space that sits beside the fallopian tube, in the tissue between the tube and the ovary. A cyst is any closed space in a tissue that contains fluid. The prefix “para” means beside, so the name describes where the cyst is.
Your report may use one of several other names for the same thing. Paraovarian cyst and parovarian cyst are used when the cyst sits closer to the ovary. Older reports sometimes say hydatid cyst of Morgagni, a term for a small cyst hanging from the fringed end of the fallopian tube. That term is no longer recommended, but it still appears in practice.
Paratubal cysts are common. They account for roughly 10 percent of masses found beside the uterus, and most are small and cause no trouble. They occur at any age and are found most often during the reproductive years. A paratubal cyst is not cancer, and most never cause a problem. This article will help you understand what this diagnosis means on your pathology report, what each term means, and why it matters for your care.
Paratubal cysts develop from small pieces of tissue left over from the way the reproductive organs form before birth. Early in development, every fetus has two sets of paired tubes running alongside the developing kidneys. In a female fetus, one set goes on to form the fallopian tubes, uterus, and upper vagina. The other set mostly disappears. Small fragments of either set can persist in the tissue between the ovary and the fallopian tube, and a cyst can form from one of those fragments later in life.
Pathologists recognize three origins, and the lining cells often indicate which one applies.
Whichever the origin, a paratubal cyst is a developmental leftover rather than a disease.
Most paratubal cysts cause no symptoms and are found by chance, either on an imaging test performed for another reason or during surgery. Small cysts are often discovered only when the tissue is examined in the laboratory. When symptoms occur, they usually come from the cyst’s size or a complication.
Sudden severe pelvic pain has several possible causes, some of which need urgent treatment. It should always be assessed promptly.
A paratubal cyst is often suspected on an ultrasound before surgery. On a scan it appears as a smooth, thin-walled, single-chambered cyst filled with clear fluid. The most useful clue is that a normal ovary can be seen separately, next to the cyst rather than containing it. Even so, a paratubal cyst is frequently mistaken for an ovarian cyst on imaging, because the two sit close together.
A definite diagnosis is made only after the cyst is removed and examined under the microscope by a pathologist. In many cases, the cyst was not the reason for the operation, and the pathologist found it while examining a fallopian tube or ovary removed for another reason.
During the operation, the surgeon may request an intraoperative consultation, also called a frozen section. The pathologist examines a piece of the cyst while the patient is still in the operating room and gives a preliminary diagnosis within minutes. The pathologist makes the final diagnosis later, once the entire specimen has been examined.
The pathologist examines the entire lining of the cyst, not just a single piece. This matters because the rare tumors that arise in a paratubal cyst grow from the lining and may involve only a small area.
A paratubal cyst is a fluid-filled space beside the fallopian tube, surrounded by a thin wall and lined by a single layer of cells. To the naked eye, it is a thin-walled, translucent sac containing clear fluid. Under the microscope, the pathologist looks for the following features.
Along with the diagnosis of a paratubal cyst, your pathology report may describe several other features of the cyst and the tissue around it.
Yes, but it is rare, and the way this is usually written makes it sound more likely than it is. A tumor arising in a paratubal cyst grows from the lining cells. Most of the reported cases have been borderline tumors, which sit between benign and cancerous and have an excellent outlook after removal. Cancers arising in a paratubal cyst are rarer still, and only a small number have ever been described in the medical literature.
You may come across a figure of about 2 to 3 percent for tumors found in paraovarian masses. That number comes from surgical series, which include only cysts that were removed because they were large, growing, or looked unusual on imaging. It does not describe the small cysts that turn up incidentally, which make up the great majority.
The practical point is this. If your report says paratubal cyst with no other qualifying words, the pathologist examined the lining and found no tumor. If a borderline tumor or a cancer had been present, the report would name it directly, nd the diagnosis would not be a simple paratubal cyst.
A paratubal cyst is benign. Once it has been removed, it is considered dealt with, and it does not turn into cancer over time. Points your doctor may raise include:
Sudden severe pelvic pain, especially with nausea or vomiting, should be assessed urgently, since torsion and rupture both need prompt treatment.