Malignant ascites is an accumulation of fluid in the abdominal cavity and this fluid has cancerous cells in its content. This medical condition often occurs in patients with liver diseases, nephrotic syndrome and primary cancer especially cancer of the uterus, cervix, ovaries, breast, lungs and gastrointestinal tract.
The tumor cells spreads into the abdominal cavity as a result of improper regulation of blood flow into the peritoneum and lymphatic flow out of it. People who have malignant ascites usually have a very poor prognosis of survival rate of 1 to 4 months, though this is dependent on the primary cancer present. The treatment of malignant ascites is palliative even though it has a high morbidity rate. The difficulty in treating the disease is probably due to the underlying cancer and also the involvement of the peritoneum.
The abdominal lining is formed by the peritoneum, the peritoneum is made up of two layers, and the outer layer is called the parietal peritoneum which lines the abdominal wall while the inner layer is called the visceral peritoneum and covers the internal organs of the abdomen. The parietal peritoneum has the mesothelial tissue and a simple squamous epithelium, the inner layer has the lamina propria which fixes to the capsule of the internal organs.
The squamous epithelium has foramens which permits some macromolecules and cells into the abdomen. Blood plasma enters the cavity through capillaries of the peritoneum draining off through lymphatic open ends. In healthy people the peritoneal cavity has about 50-100ml of fluid which helps organ slide freely against each other.
The tumor cells which infiltrates the abdominal cavity thus disturbs normal fluid regulation by increasing in flow of plasma and decreasing out flow of lymph. The cancer cells also produce Vascular Endothelial Growth Factor (VEGF) which leads to presence of new tumor blood vessels.
Also VEGF increase permeability of peritoneal capillaries. Therefore the new cancer blood vessels and the peritoneal vessels which are now permeable are responsible for the increase in the flow of fluids into the peritoneal cavity. Also lymphatic obstruction contributes to fluid accumulation in the abdominal cavity.
The symptoms of malignant ascites are pain in the abdomen, anorexia, dyspnea, nausea and vomiting, swollen abdomen as a result of accumulation of fluid. There is also a positive fluid wave on palpation of the abdomen.
To diagnose malignant ascites aside from the symptoms, blood analysis is done to confirm leukocytosis and increased ESR to indicate inflammatory process. Increased neutrophil confirms bacterial infection. To put a diagnosis on malignant ascites an ultrasound is the most effective and most accurate method in its diagnosis.
After diagnosis is made and malignant ascites is confirmed, the treatment is given which is commonly diuretic therapy whose aim is to improve renal blood flow, increase glomerular filteration rate, urine formation and expulsion which helps to reduce fluid retention. The diuretic of choice is spirolactone which is a potassium sparing diuretics so as not to cause a new problem of the body.
Although treatment is given, it is not a cure but a palliative treatment to improve patient’s condition because malignant ascites cannot be completely cured.