Malignant peritoneal mesothelioma, also known as primary peritoneal mesothelioma, is a tumor originating from the epithelial and mesothelial tissues of the peritoneum. This disease is less common than pleural mesothelioma, with a slightly higher incidence in males than in females. The cause of the disease is associated with asbestos exposure, and the onset is often delayed, typically occurring more than 30 years after exposure. Benign mesotheliomas are usually solitary and commonly located in the peritoneum near the fallopian tubes or the top of the uterus, with rare occurrences in other areas. Malignant mesotheliomas tend to be diffuse, covering all or part of the peritoneum.

bubble_chart Diagnosis

1. Medical History Inquiry

Unexplained abdominal pain, abdominal distension and fullness, and digestive tract dysfunction. Abdominal pain can manifest in various forms, but its persistent nature is a common characteristic. The incidence of ascites is very high, exceeding 90%. After a variable duration of abdominal pain, ascites may suddenly appear, but it can also occur alone in the early stages. The ascites is typically copious and refractory. General condition shows little change over an extended period, with preserved appetite, no significant weight loss, and absence of fever. Spontaneous hypoglycemia may occasionally occur. Symptoms such as chest pain, dyspnea, cough, and other signs of pleural mesothelioma may accompany the condition.

2. Physical Examination Findings

Abdominal distension or frog belly, with positive shifting dullness; palpation may reveal single or multiple masses of varying sizes, usually with minimal tenderness. If accompanied by pleural mesothelioma, positive signs of pleural effusion may be detected.

Ultrasound and CT scans may reveal thin, sheet-like tumor images and ascites. The ascitic fluid can be exudative or bloody. Elevated hyaluronic acid levels in ascites (e.g., up to 120 µg/mL) are highly suggestive for diagnosis. The presence of neoplastic mesothelioma cells in ascites is diagnostic. Chromosomal analysis of mesothelial cells in ascites can also aid in diagnosis. Laparoscopy may show nodules and patches covering the peritoneal surface, and biopsy pathology can confirm the diagnosis. Differential diagnosis should include subcutaneous nodular peritonitis and peritoneal metastatic tumors.

bubble_chart Treatment Measures

The results of general radiotherapy and chemotherapy are unsatisfactory. In recent years, some reports indicate that treatment with doxorubicin has extended survival in 50% of cases, but other reports suggest it is ineffective. Some also advocate for immunotherapy, though further observation is needed. Generally, death occurs within 1 to 2 years after diagnosis.