Meigs' Syndrome

The three cardinal features of Meigs' syndrome are:

• A benign ovarian tumour
• Ascites and pleural effusion
• If the tumour is resected, the fluid resolves

The ovarian tumour is usually a fibroma but may be a thecoma, cystadenoma, or granulosa cell tumour. When the histology is other than fibroma, it is sometimes referred to as pseudo-Meigs' syndrome.

There appears to be an inflammatory reaction that causes the peritoneal and pleural fluid but the underlying aetiology is unclear.¹ Even the source of the fluid is unclear.

A study of ovarian tumours with ascites found that only those larger than 10 cm in diameter with a myxoid component to the stroma were associated with ascites. These authors suggested that this favours secretion of fluid from the tumour rather than the peritoneum or pleura.²

The tumour marker CA-125 is often elevated but usually less so than in malignancy. CA-125 expression is localised on the peritoneum rather than the ovary.³

Meigs' syndrome accounts for about 1% of ovarian tumours. It is very uncommon before 40 years of age and becomes more frequent as the years progress but there are some reports of it arising from teratomas or cystadenomas in pre-pubertal girls.

Most features are related to ascites and pleural effusion but before the menopause there may be menstrual symptoms too.

• Fatigue
• Dyspnoea (initially on exertion)
• Swollen abdomen with associated weight gain
• Non-productive cough
• Amenorrhoea or irregular menstruation

Examination

• Reduction in lung capacity may produce tachypnoea and tachycardia
• Examination of the chest will reveal dullness to percussion over the effusion. There will be decreased breath sounds and decreased tactile vocal fremitus.
• The effusion tends to be right-sided but can be bilateral. There appears to be no adequate explanation for this unilaterality. A large right-sided effusion will displace the mediastinum to the left with deviation of the trachea to the left and displacement of the apex beat.
• Abdominal examination may reveal a tumour arising from the pelvis but this may be obscured by ascites. The features of ascites include a fullness of the flanks and shifting dullness.
• Pelvic examination may reveal an ovarian mass.

The main differential diagnosis is with a malignant ovarian tumour:

• They are much more common than Meigs' syndrome and tend to produce profuse ascites with a high protein content.
• Pleural effusion is less common unless due to pulmonary metastases.

Other considerations include:

• Other cancers including colon and lung⁴
• Tuberculosis
• Nephrotic syndrome
• Congestive heart failure
• Cirrhosis

• Check urine for protein.
• Routine blood tests would include FBC, U & E, LFTs, including plasma proteins.
• CA-125 is a tumour marker that tends to be mildly elevated in Meigs' syndrome and markedly elevated in ovarian malignancy. This is not reliable and cases are described with very high CA-125 and normal levels.⁵ It can also be normal in ovarian malignancy.
• CXR (AP and lateral) will show the degree of pulmonary effusion.
• Abdominal ultrasound will demonstrate the ascites and should outline the ovarian tumour too. For ovarian tumours, MRI is the first line after CT but CT is rarely used.
• Paracentesis and aspiration of pleural fluid serves two purposes. It helps to relieve symptoms and fluid should be sent for cytology. This is very important in distinguishing malignant ascites from Meigs' syndrome. The fluid tends to have the features of a transudate although sometimes it does appear to be an exudate. In ovarian carcinoma the protein content is usually high. Pleural and ascitic fluid should also be examined for protein, glucose, amylase, cell count, organisms and AAFB if indicated.
• If congestive heart failure is suspected, ECG will be required. Echocardiogram is indicated only if the ECG is abnormal.

• Pseudo-Meigs' syndrome is characterised by pleural effusion, ascites, and benign ovarian tumours (other than fibromas).⁶ The tumours may include those of the fallopian tube, uterus, mature teratomas, struma ovarii and ovarian leiomyomas. Ovarian or metastatic gastrointestinal malignancies are sometimes included within this terminology.
• Atypical Meigs' syndrome consists of a benign pelvic mass with a right-sided pleural effusion, but no ascites is present. This is rare. The pleural effusion resolves after resection of the tumour.
• Pseudo-pseudo Meigs' syndrome may occur in patients with systemic lupus erythematosus and enlarged ovaries.

The essential management is surgical removal of the tumour but before operation, aspiration of pleural effusion and ascites should be performed to improve pulmonary function.⁶

The operation includes full laparotomy to exclude other causes of malignancy including bowel.

• In women of reproductive age a unilateral salpingo-oophorectomy is usually performed.
• In girls who are before the menarche, wedge resection may be preferred if feasible.
• After the menopause an operation of total abdominal hysterectomy with bilateral salpingo-oophorectomy is usual.

Within weeks to months of operation the ascites and pleural effusion resolve and the CA-125 returns to normal. Postoperative resolution of the fluid is part of the definition of the disease. As it is a benign tumour the prognosis is excellent. If there is functioning ovarian tissue, fertility should be preserved.

• In 1934 Salmon described the association of pleural effusion with benign pelvic tumours.
• In 1936 Meigs and Cass described 7 cases of ovarian fibromas associated with ascites and pleural effusion.⁷
• In 1954 Meigs proposed limiting the diagnosis of Meigs' syndrome to benign and solid ovarian tumours with ascites and pleural effusion, and the condition that removal of the tumour cures the patient without recurrence.

Joe Vincent Meigs was an American Obstetrician and Gynaecologist who was born in 1892 and died in 1963.