Case Presentation: A 39-year-old African American nulliparous female with a history of endometriosis and recent outside hospitalization presents with 10 days of acute on chronic lower abdominal pain and dyspnea. On exam, she has a distended abdomen and decreased breath sounds over the right lung. Initial labs are unremarkable including complete blood count, comprehensive metabolic panel, and lipase. Abdominal/pelvic CT scan is notable for large volume abdominal and pelvic ascites, a plaque-like soft tissue mass along her anterior abdominal wall and in bilateral adnexa, peritoneal nodularity in her left upper quadrant, two enhancing right sided pleural nodules, and a large left pleural effusion. CA 125 is sent and returns elevated at 369, concerning for a gynecologic malignancy. Further history is obtained and reveals her ascites and pleural effusions are chronic, and recent thoracentesis and paracentesis at the outside hospital demonstrated negative cytology. It is also discovered her endometriosis had previously been well-controlled with Lupron, but this was discontinued by the patient 18 months prior. Her presentation is ultimately attributed to an uncommon complication of endometriosis. She was advised to restart Lupron and discharged with gynecological follow up.

Discussion: Large volume ascites and pleural effusions are rare complications of endometriosis. This presentation can be easily confused with malignant or other gynecological processes such as Meig’s syndrome, the triad of benign ovarian tumor, ascites, and pleural effusion. Women with endometriosis classically present during their reproductive years with pelvic pain, dysmenorrhea, dyspareunia, infertility, and/or an ovarian mass. The majority of cases of endometriosis-associated ascites occur in nulliparous women of African origin, much like our patient. Patients presenting with ascites and pleural effusion should be evaluated for malignancy and other etiologies, with workup including thoracentesis and/or paracentesis with proper fluid analysis including cytology. CT and MRI are useful imaging modalities to assess for an ovarian tumor. Endometriosis can be definitively diagnosed with biopsy and histological evaluation. Medical management with GnRH agonists are effective treatments for patients with endometriosis presenting with ascites and pleural effusion.

Conclusions: While the detection of a pelvic mass, ascites, pleural effusion, and elevated CA 125 should raise suspicion for malignancy, it is important to consider other diagnoses when malignancy workup is unrevealing. Endometriosis presenting with ascites and pleural effusion is most common in nulliparous women of African origin. It is important for clinicians to be made aware of this rare presentation, as effective medical management can avoid unnecessary invasive procedures and major surgeries.