Chylous ascitis - It is defined as presence of milky, turbid or creamy ascitic fluid due to presence of increased triglyceride (fat) content of>1000 mg/dl either due to presence of intestinal or thoracic lymph. The common causes are congenital anomaly of lymphatics, obstruction of thoracic duct within its abdominal portion due to trauma, tumor, large lymph nodes and rupture of major lymphatic channel. The other causes are tuberculosis, filariasis, nephrotic syndrome, cirrhosis, rheumatoid arthritis and other serositis. When the patient is fasting, the milky color will fade and the fluid looks like a transudate with predominance of lymphocytes.

In patients with chronic peritonitis and persistent ascitis, the fluid color may be milky due to degeneration of inflammatory products (leukocytes/tumor cell) and may be confused with chylous fluid. However it can be distinguished from chylous ascitis by doing the ether test. When a drop of ether is added to the turbid ascitic fluid, the top layer clears in chylous fluid whereas it does not in a pseudochylous fluid.

Treatment of chylous ascitis consists of dietary management and therapeutic paracentesis. A low fat diet containing medium chain triglycerides with high protein diet is advocated. (MCT are directly absorbed in the portal circulation). Treatment may be required for several months for effective medical management. A surgical abdominal exploration may be required to detect the site of the leak.

Tuberculous ascitis may occur with few constitutional symptoms despite extensive involvement of the peritoneum. Radiographic evidence of pulmonary lesions is such cases are minimal. Direct smear of ascitic fluid may not show acid-fast bacillus. The best diagnostic methods are culture of the fluid and histopathological reading of biopsy of the peritoneum. Treatment consists of anti tuberculous drugs with surgery being reserved for cases with enteritis leading to bowel obstruction, perforation, fistula or a mass that does not resolve with drug therapy.