Paratubal cysts are noncancerous, fluid-filled sacs that form in the pelvis, located near the fallopian tubes and ovaries. They are a common finding, representing about 10% of all masses found in the adnexa (the region containing the uterus, ovaries, and fallopian tubes). These cysts are almost always benign and typically do not cause noticeable symptoms. Understanding their origins and management is important for women who discover them.
Anatomy and Types of Paratubal Cysts
Paratubal cysts are distinct from ovarian cysts because they grow separate from the ovary, located within the broad ligament of the pelvis. They are classified as paratubal or paraovarian based on their location relative to the fallopian tube and ovary, and the terms are often used interchangeably.
These cysts are usually small, ranging from two to 20 millimeters in diameter, but they can occasionally grow larger. They are frequently found on only one side of the reproductive system. A specific type of pedunculated paratubal cyst, attached by a stalk, is known as the Hydatid of Morgagni.
Understanding Their Embryonic Origins
The underlying cause of paratubal cysts is their congenital origin, meaning they arise from remnants of structures that were present during embryonic development. They specifically develop from the vestiges of the Müllerian and Wolffian duct systems, which are the primitive structures that eventually form the female and male reproductive tracts.
In a female fetus, the Müllerian ducts develop into the fallopian tubes, uterus, and upper vagina, while the Wolffian ducts typically regress. Paratubal cysts develop when small pieces of these embryonic ducts fail to completely disappear, leaving behind remnants that can later form fluid-filled sacs.
Diagnosis and Monitoring Requirements
Paratubal cysts are asymptomatic and are most often discovered incidentally during imaging performed for other reasons. They may be found during routine pelvic exams, fertility workups, or ultrasound screenings. When symptoms occur, it is typically due to increased size or a rare complication like torsion (a twisting of the cyst).
The primary diagnostic tool is a pelvic ultrasound, often performed transvaginally, which uses sound waves to create images of the pelvic organs. It can be challenging to reliably distinguish a paratubal cyst from an ovarian cyst, especially if the paratubal cyst is located close to the ovary. A characteristic finding during laparoscopy is the presence of blood vessels crossing over the cyst surface, which helps differentiate it from a true ovarian mass.
For small cysts, generally less than three to five centimeters, the standard approach is expectant management, often called “watch and wait.” This monitoring involves periodic follow-up ultrasounds to check the cyst’s size and stability. Intervention is typically reserved for cysts that are larger, cause persistent pain, or show changes suggesting a risk of complication.
Treatment Options and Surgical Management
Given that most paratubal cysts are small, they often require no active treatment beyond expectant management. Some small cysts may even resolve on their own. Active treatment becomes necessary if the cyst is large, causes significant pain or pressure, or presents a risk of complications like torsion.
Surgical Intervention
Torsion, where the cyst twists on its stalk, is a medical emergency that can cut off blood flow to the fallopian tube and ovary, causing acute, severe abdominal pain. When the cyst size exceeds a threshold (often seven to ten centimeters), surgical removal is typically recommended. The goal of surgery is to remove the cyst while preserving the surrounding reproductive organs.
The standard surgical approach is laparoscopy, a minimally invasive procedure. This technique involves making small incisions to insert a camera and specialized instruments. During the procedure, the surgeon may perform a cystectomy (complete excision of the cyst wall), or aspirate the fluid from a small cyst and then coagulate the remaining lining.
Laparoscopy offers advantages over traditional open surgery, including faster recovery times and less pain. For larger cysts, decompression by aspirating the fluid first facilitates the complete removal of the cyst wall. The prognosis following surgical removal is generally excellent, especially when techniques preserve the fallopian tube and ovary, which is important for maintaining fertility.