When the abdominal cavity is filled with Asbestos fibers, the body reacts by sending additional fluid to relieve the irritation caused by the damage. That fluid (called ascites) can build up so much that the stomach becomes painful and distended. Often that is how Peritoneal Mesothelioma is discovered. Doctors can use a needle biopsy to removed liters of abdominal fluid. The fluid can be spun in a centrifuge to create a fluid biopsy and diagnose cancer.