Common Malignancies That Cause Ascites The most common malignancies causing ascites are ovarian cancer, pancreatic cancer, gastric cancer, and hepatocellular carcinoma 1. Ovarian Cancer - Most common cause of malignant ascites in women. - Often presents with large-volume ascites. - Ovarian cancer is particularly notable for its association with malignant ascites, with studies indicating that it is the most frequent cause among gynecological malignancies. - Mechanism: Peritoneal carcinomatosis and increased vascular permeability. 2. Gastric Cancer - Can lead to peritoneal carcinomatosis. - Signet ring cell type is especially notorious. - May present as Krukenberg tumors (ovarian mets). 3. Pancreatic Cancer - Advanced disease may cause ascites via lymphatic obstruction, peritoneal carcinomatosis or liver metastasis. 4. Colon Cancer - Particularly when there is peritoneal seeding or liver metastases causing portal hypertension. 5. Liver Cancer (Hepatocellular Carcinoma – HCC) - Causes ascites by portal hypertension or hepatic vein obstruction (Budd-Chiari syndrome). 6. Breast Cancer - Metastatic spread to the peritoneum or liver. 7. Lung Cancer - Especially adenocarcinoma, due to its predilection for serosal surfaces. 8. Lymphoma - Ascites may occur via lymphatic obstruction or direct peritoneal involvement. 9. Peritoneal Mesothelioma - Rare, but can cause massive ascites. Mechanisms of Malignant Ascites: • PERITONEAL CARCINOMATOSIS - Tumor cells seed the peritoneal lining and increase vascular permeability. • LYMPHATIC OBSTRUCTION - Tumor blocks lymphatic drainage. • PORTAL HYPERTENSION - Seen with liver metastases or HCC. • HYPOALBUMINEMIA - Due to cancer-related malnutrition or liver dysfunction. #Malignant #Ascites #Differential #Diagnosis #Hepatology #oncology
