The Demons-Meigs syndrome should usually be evoked in case of presence of a typical triad: abdominopelvic mass, ascites and hydrothorax. Demons was the first, between 1887 and 1902, who indicated that removal of the tumor (benign ovarian cyst, solid ovarian tumor, fibroma of the broad ligament) was essential for the patient to be cured from effusions (¹, ²). In 1937, Meigs came to similar conclusion about ovarian fibromas and granulosa cell tumors. The name of Demons-Meigs was attributed to this syndrome. However,the physiopathology of the ascites and the hydrothorax still remain obscure (¹). Ascites occurs in 10-15% of the cases. Hydrothorax is present in only 1% of the cases and is mostly unilateral right-sided (², ³). Ascitic and pleural fluids are similar in nature (exudative or transudative). The circumstances of discovery are variable and can be related to the consequences of the triad syndrome (weight gain, abdominal pain, respiratory distress). The patient can also be asymptomatic (fortutious discovery) (²–⁵). The serum CA-125 level is not specific and does not always increase (⁶). Preoperative biologic (chemistry and cytologic study) and radiologic findings (ultrasound, computed tomography scan and magnetic resonance imaging) can be highly accurate in diagnosis (origin of the mass, no signs of distant metastases) and surgical management strategy (⁴–⁷). This preoperative recognition should be considered in the differential diagnosis and appears essential to prevent the realization of unnecessary surgical procedures. Final histologic findings which exclude malignancy and complete and definitive remission after surgery confirm this particular syndrome. For Brun, Demons’ syndrome should include benign genital tumors, the Demons-Meigs eponym must be reserved for the description of ovarian fibromas and granulosa cell tumors, and the Demons’ pseudosyndrome for all other entities (¹). In this case report, the large ovarian tumor with right hydrothorax and elevated serum CA-125 level indicated a Demons-Meigs syndrome. The final histologic findings demonstrated Demons’ pseudo-syndrome which is an unusual situation when it's related to a borderline ovarian tumor (⁸). Surgical management consisted of a bilateral salpingo-oophorectomy with hysterectomy in postmeno-pausal women or unilateral (salpingo-) oophorectomy in young patients with desire for pregnancy (¹, ⁴).

A 32-year-old-woman was referred in April 2012 to the emergency departement of our maternity unit (General Hospital of Thiers, France) for probable pregnancy at term with beginning of labor. The condition staretd 9 months before by the occurrence of progressive abdominal distension, dyspnea and secondary amenorrhea. Physical examination revealed a voluminous painful abdominopelvic mass, diffuse, extending from the pelvis to the upper abdomen and large right pleural effusion (Figure 1). On vaginal examination, it was difficult to relate the mass to any obstetrico-gynecologic origin. Ultrasound showed a liquid predominant tumor measuring more than 300 mm in diameter and no pregnancy. Thoraco-abdominal CT-scan showed a right hydrothorax, confirmed the abdominopelvic mass which filled all the peritoneal cavity without signs of distant metastases or lymphadenopathy (Figures 2–4). Serum CA-125 was 289 U/ml and ACE was normal. Given the importance of dyspnea, pleural paracentesis (250 ml) was performed preoperatively. The chemistry and cytologic study of the pleural effusion was in favor of an exsudate without any suspected malignant cells. Therefore, an exploratory laparoscopy was performed. It revealed a voluminous ovarian cyst without vegetation or any suspected peritoneal implant. The liver was macroscopically normal. The visualization of the uterus was impossible. The aspiration of 15 liters of a brownish liquid permitted a midline laparotomy of limited size, under and above the umbilicus. The aspiration was completed (23 liters) and a right ovarian cyst was identified (Figures 5, 6). The uterus, the controlateral ovary, the bladder and the pelvic peritoneum were macroscopically normal. A right adnexectomy was performed and a frozen section pathologic exam demonstrated benign mucinous cystadenoma. The postoperative course was uneventful and the patient was discharged 5 days after the procedure. The final histologic examination objectified intracystic intestinal type ovarian mucinous borderline tumor which corresponded to a Demons’ pseudosyndrome. After multidisciplinary consultation, the patient was re-operated a month later for a staging surgery. The exploration didn't reveal any suspected lesions and multiple biopsies, an appendectomy and an omentectomy were performed by laparoscopy. The patient recovered quickly. Serum CA-125 level was normal at the time of the re-operation and 24 months after the initial surgery.

An abdominopelvic mass associated to ascites, hydrothorax and elevated CA-125 serum level can imitate an advanced ovarian cancer. Nevertheless, a Demons-Meigs syndrome or a Demons’ pseudo-syndrome should be suspected when faced with a negative cytologic analysis of the ascitic and pleural effusion and no peritoneal implant on CT-scan. This preoperative diagnosis enables us to avoid useless surgical procedures.