Meigs syndrome is a rare condition in which a benign (noncancerous) ovarian tumor causes fluid to build up in the abdomen and around the lungs. The defining feature of this syndrome is that both fluid collections completely resolve once the tumor is surgically removed, typically within a few weeks. It most commonly affects women with a type of solid ovarian tumor called a fibroma, though a few other benign ovarian tumor types can also trigger it.
The Three Features That Define It
Meigs syndrome is diagnosed when three things are present together: a benign solid ovarian tumor, fluid accumulation in the abdomen (ascites), and fluid around one or both lungs (pleural effusion). The ovarian tumor is usually a fibroma, but thecomas, granulosa cell tumors, and Brenner tumors also qualify. A strict diagnostic criterion, established in 1954, adds one more requirement: removing the tumor must cure the fluid buildup completely, with no recurrence.
This triad matters because it looks alarming. Fluid in the abdomen plus fluid around the lungs plus an ovarian mass is exactly what advanced ovarian cancer can look like. The critical difference is that in Meigs syndrome, the tumor is entirely benign and surgery is curative.
How It Feels
Most women with Meigs syndrome notice symptoms caused by the fluid, not the tumor itself. Abdominal swelling and bloating from ascites are common, along with a feeling of fullness or pressure in the pelvis. When fluid collects around the lungs, it can cause shortness of breath, a dry cough, or chest tightness, especially when lying flat. Some women also experience fatigue and unintentional weight loss. These symptoms tend to develop gradually and often prompt a visit to the doctor before anyone suspects an ovarian tumor is involved.
Why Fluid Builds Up
The exact mechanism is not fully understood, but the tumor itself appears to be the source. Ovarian fibromas and similar tumors can leak fluid from their surface, and as the tumor grows, the amount of fluid increases. This fluid first collects in the abdomen as ascites. From there, it migrates upward through tiny lymphatic channels in the diaphragm (the muscle separating the abdomen from the chest), entering the space around the lungs. The pleural effusion is more common on the right side, likely because of how lymphatic drainage flows through the right side of the diaphragm.
Why It Mimics Ovarian Cancer
One of the most challenging aspects of Meigs syndrome is that it can closely resemble ovarian cancer on initial evaluation. Imaging studies show an ovarian mass alongside fluid in two body compartments, which raises immediate concern for malignancy. To make things more confusing, a blood marker called CA-125, often used to screen for ovarian cancer, can be significantly elevated in Meigs syndrome. In reported cases, CA-125 levels have ranged from 42 to nearly 4,000 IU/mL. Values above 1,000 are rare in Meigs syndrome but do occur. Since CA-125 is generally higher in women with malignant tumors, an elevated result can push the clinical suspicion toward cancer even when the tumor is benign.
This mimicry means that many women with Meigs syndrome initially undergo workups for suspected ovarian cancer. The benign nature of the tumor is often only confirmed after surgery, when pathologists examine the removed tissue under a microscope.
Meigs vs. Pseudo-Meigs Syndrome
A related condition called pseudo-Meigs syndrome produces the same combination of ascites and pleural effusion, but the underlying tumor is different. In pseudo-Meigs, the tumor is either a benign ovarian growth other than a fibroma (such as a teratoma, mucinous cystadenoma, or struma ovarii), a uterine fibroid, or even a malignant ovarian tumor. The distinction matters mostly for classification. From a patient’s perspective, both conditions present similarly and are managed with surgery, though outcomes depend on whether the tumor turns out to be benign or malignant.
Treatment and Recovery
Surgery to remove the ovarian tumor is the only effective treatment, and it is essentially curative. Once the tumor is out, the ascites and pleural effusion resolve on their own, generally within a few weeks. No additional treatment such as chemotherapy or radiation is needed because the tumor is benign. In documented cases, follow-up imaging months after surgery confirms that the fluid does not return.
Before surgery, doctors may drain fluid from the chest or abdomen to relieve symptoms like shortness of breath, but this is a temporary measure. The fluid will continue to reaccumulate as long as the tumor remains. Definitive resolution only comes with tumor removal.
Recovery from surgery follows the typical timeline for ovarian tumor removal. Most women can expect to return to normal activities within several weeks, depending on whether the surgery was performed through a small incision or a larger abdominal opening. The prognosis is excellent because the underlying tumor is benign, and recurrence of the syndrome after complete removal is not expected.