Diagnosis of malignant ascites

Tumor cells in ascites aspirate

In clinical practice, ascites is usually diagnosed by anamnesis, physical examination, sonography or other imaging procedures and a diagnostic paracentesis.

In addition to abdominal swelling, typical symptoms of ascites include abdominal pain, dyspnoea, constipation, ileus, feeling of satiety, anorexia and nausea, as well as weight gain or peripheral edema. Imaging diagnostics (CT, MRI, ultrasonography) can detect small amounts of fluid. Neither physical examination nor imaging diagnostics can differentiate between a benign or malignant form of ascites. Therefore a definitive diagnosis is based on ascitic fluid analysis, imaging diagnostics and blood tests.

Differential diagnosis of malignant ascites

The detection of tumor cells in the ascitic fluid by cytology is a highly specific indicator for a malignant cause. However, only about 60 % of malignant ascitic fluid samples (aspirates) are positive for tumor cells, so if malignant disease is suspected, the examination must be repeated.

In cases of negative cancer cytology, biochemical markers in the ascites may also help to identify an underlying malignancy.