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 other sites being rare. Malignant mesotheliomas tend to be diffuse, covering all or part of the peritoneum.

bubble_chart Diagnosis

1. History Taking

   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 period of abdominal pain, ascites may suddenly appear, though it can also present alone in the early stages. The ascites is often copious and persistent. General health remains largely unchanged over an extended period, with preserved appetite, minimal weight loss, and absence of fever. Spontaneous hypoglycemia may occasionally occur. Symptoms such as chest pain, dyspnea, and cough may accompany pleural mesothelioma.

2. Physical Examination Findings

   Abdominal distension or a frog-belly appearance, with shifting dullness positive; palpation may reveal single or multiple masses of varying sizes, typically with minimal tenderness. If pleural mesothelioma is present, signs of pleural effusion may be detected.

3. Laboratory Tests

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

bubble_chart Treatment Measures

The results of conventional radiotherapy and chemotherapy are generally unsatisfactory. In recent years, some reports indicate that doxorubicin treatment has extended survival in 50% of cases, while others suggest it is ineffective. Some advocate for immunotherapy, but further observation is still needed.

bubble_chart Prognosis

Death usually occurs within 1 to 2 years after diagnosis.

bubble_chart Differentiation

It is necessary to differentiate from subcutaneous nodular peritonitis and peritoneal metastatic tumors.