A paratubal cyst is a fluid-filled sac that forms near the fallopian tube and ovary. Also known as paraovarian cysts, they develop in the adnexa, the area around the ovaries and fallopian tubes. Paratubal cysts are common and almost always benign (non-cancerous). Many small paratubal cysts often go undiagnosed as they cause no symptoms and may even dissolve on their own over time.
How Paratubal Cysts Are Measured
Paratubal cysts are frequently discovered incidentally during a routine pelvic examination or imaging procedures performed for unrelated health concerns. The primary method used to identify and measure these cysts is medical ultrasound, which can include transvaginal, pelvic, or transabdominal approaches.
During an ultrasound, the size of a paratubal cyst is reported in centimeters. Sonographic evaluation aims to differentiate these cysts from ovarian cysts by visualizing the ipsilateral ovary separately from the cyst. While ultrasound is effective for detection and measurement, a definitive diagnosis sometimes requires the cyst to be surgically removed and microscopic examination. [1 (How Paratubal Cysts Are Measured), 3 (Paratubal cyst – MyPathologyReport), 5 (Paraovarian cyst | Radiology Reference Article | Radiopaedia.org)]
Common Size Classifications
Paratubal cysts are categorized by size, which often correlates with the likelihood of experiencing symptoms. Small cysts are defined as those under 3 centimeters. These are the most common type, do not cause symptoms, and are often monitored without active intervention.
Medium-sized cysts range from 3 to 7 centimeters. While these may still be asymptomatic, some individuals might begin to experience mild discomfort such as a dull ache or a feeling of pressure in the pelvic area. The presence of symptoms at this size can vary significantly among individuals.
Cysts considered large are those greater than 7 centimeters. These cysts are more likely to cause noticeable symptoms due to their increased mass and potential to press on surrounding structures. Very large paratubal cysts can grow to significant sizes, sometimes exceeding 15 to 20 centimeters. [1, 2 (Paratubal Cyst | Best Gynecologist Los Angeles Dr. Thais Aliabadi), 4 (A rare case of large paratubal cyst –a diagnostic dilemma), 5 (Adolescent fallopian tube cysts (paratubal) – Children’s Health Gynecology)]
When Cyst Size Requires Medical Attention
A paratubal cyst’s size can influence whether it requires medical attention, particularly if it grows large enough to cause complications. One concern is when a large cyst exerts pressure on nearby organs, such as the bladder, bowel, kidney, or uterus. This pressure can lead to symptoms like persistent pelvic pain, bloating, constipation, or increased urinary frequency. [2 (Paraovarian Cyst: Sizes, Symptoms, Diagnosis & Treatment – Cleveland Clinic), 3 (Paratubal Cyst: Causes, Symptoms, Treatment, and More – Healthline), 5 (Para-ovarian Cysts – ISUOG)]
Another potential complication related to cyst size is adnexal torsion, which is a medical emergency. This occurs when the ovary and/or fallopian tube twists on its supporting tissues, potentially cutting off its blood supply. While the cyst itself is distinct from the ovary, a large paratubal cyst, especially those over 4 centimeters, can increase the risk of this twisting due to its weight and altered center of gravity. Adnexal torsion presents with sudden, sharp abdominal pain, accompanied by nausea and vomiting, requiring immediate surgical intervention to preserve the affected reproductive structures. [1 (Adolescent fallopian tube cysts (paratubal) – Children’s Health Gynecology), 2 (Paraovarian Cyst: Sizes, Symptoms, Diagnosis & Treatment – Cleveland Clinic), 3 (Paratubal Cyst: Causes, Symptoms, Treatment, and More – Healthline)]