C45-24 When Recurrent Pleural Effusions Aren’t Malignant: A Case of Pseudo-Meig’s Syndrome

Abstract Meig’s syndrome is defined by the classic tetrad of benign ovarian tumor, ascites, pleural effusion, and resolution after tumor resection. Pseudo-Meig’s syndrome presents with a similar clinical picture but arises from ovarian tumors other than fibromas, including malignant or metastatic lesions, necessitating careful differentiation. We present a case of pseudo-Meig’s syndrome, initially presenting with recurrent pleural effusions and a pelvic mass. A 64-year-old woman with hypothyroidism and a remote history of an adnexal mass presented with coryzal symptoms and dyspnea. Imaging revealed a large right pleural effusion. Thoracentesis showed serosanguinous exudative lymphocyte-predominant fluid without malignant cells. CT abdomen/pelvis demonstrated a large heterogeneous right adnexal mass with ascites, and tumor markers (CA-125, CEA) were elevated. The patient improved with drainage and was discharged with outpatient follow-up. Over the next month, she was readmitted twice for worsening dyspnea with recurrent pleural effusions requiring drainage and later insertion of a chest tube, with cytology repeatedly negative for malignancy. She subsequently underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy. Pathology revealed a 7 cm mucinous adenocarcinoma of the right ovary with malignant ascitic fluid, but negative lymph node invasion. After resolution and confirmation of no further pleural fluid accumulation via point-of-care ultrasound (POCUS), all drains were removed. The patient was discharged with oncology, gynecology, and pulmonary follow-up and has remained asymptomatic without recurrence. Meig’s syndrome is estimated to be associated with ∼1% of ovarian lesions. The incidence of pseudo-Meig’s syndrome is not established in the literature, but it is thought to be extremely rare, even more so than Meig’s. A literature review identified only one other reported case of ovarian mucinous adenocarcinoma causing pseudo-Meig’s syndrome. The pathogenesis of pseudo-Meig’s syndrome remains unclear, although it is hypothesized to be multi-factorial in nature, including the upregulation of vascular endothelial growth factor (VEGF), which promotes vascular permeability, and the trans-diaphragmatic translocation of ascitic fluid, among others. Effusions predominantly involve the right hemithorax and are generally exudative, though reports vary. Its recognition and diagnosis are crucial, as treatment of the underlying ovarian lesion can resolve the effusion and prevent unnecessary investigations or treatments for conditions with similar presentations, such as malignant pleural effusion or tuberculosis. This abstract is funded by: None