Ascites, also known as abdominal dropsy or peritoneal cavity fluid, is an accumulation of fluid in the abdominal cavity caused by an imbalance of fluid flow into and out of the blood and lymphatic vessels. There are three medical conditions that may lead to the imbalance of fluid flow in the body:
- Increased pressure in the liver, often seen in patients with cirrhosis as well as patients with massive liver metastasis
- Metastasis in the peritoneum
- Left heart faliure with edema in the body, including the abdomen and the peritoneum.
The early sign of ascites includes an obvious enlargement of the abdominal which is often accompanied with weight gain and associated with leg edema. Besides an increase in abdominal circumference, symptoms of malignant ascites also include abdominal pain (which shows a malignant cause for fluid accumulation), nausea, vomiting, dyspnea, fatigue as well as wrists, ankles and feet swelling. In certain cases, an ultrasound scan of the abdomen is required to diagnose the presence of malignant ascites.
Although most commonly due to liver cirrhosis, severe liver disease or metastatic cancer, its presence can indicate other diseases such as water retention due to heart failure, nephrotic syndrome and pancreatitis. Diagnosis of the cause is often done through blood tests, abdominal ultrasonography, and puncture of the abdominal cavity or paracentesis.
Malignancy is the main cause of malignant ascites in patients with a recurrent and/or advanced cancer including patients with ovarian carcinoma, gastrointestinal tumours, as well as pancreatic, breast, lung cancer, uterine and cervical. It’s also found in many patients with a history of metastases to the peritoneum or liver, enlarged abdominal lymph nodes, or a large tumor burden.
Ovarian carcinoma is the primary tumour in most cases of cancer patients with malignant ascites, followed by gastrointestinal tumours. The location of the primary tumour remains unknown in some cases. Read about Ascites in Advanced Gastric Cancer here.
Peritoneal carcinomatosis is a type of secondary cancer that affects the lining of the abdominal cavity which often followed by malignant ascites caused by the discharge of proteinaceous fluid from tumor cells lining.
Malignancies of ovarian and urinary bladder origin as well as peritoneal mesothelioma often lead to peritoneal carcinomatosis. In such cases, ascites developed when there is a blockage of the draining lymphatic channels and increased vascular.
Colonic, breast, pancreatic, and lung cancers also may cause peritoneal carcinomatosis and/or massive liver metastases, which leads to ascites either because they obstruct/compress portal veins or because they cause liver failure.
Rarely, massive liver metastasis can cause ascites by portal hypertension. Tumor-induced portal vein thrombosis and underlying cirrhosis-related portal hypertension is also responsible for ascites in the patients with portal hypertension.
Obstruction in lymphatic system as a result of malignant lymphoma may cause chylous ascites and eventually lead to a chylothorax. Lymphomas are a group of cancers in which cells of the lymphatic system become abnormal and start to grow uncontrollably. Lymphomas can start in almost any organ of the body.
Treatment of malignant ascites may be with medication (diuretics), direct removal of the fluid by needle or paracentesis, or other treatments directed at the cause such as systemic or intraperitoneal chemotherapy. These therapeutic options, however, are limited to palliative treatment, associated with some degree of risk, and only temporarily alleviate the symptoms.