Recurrent malignant peritoneal mesothelioma: Radiological manifestations

Purpose: To describe the CT imaging findings of recurrent malignant peritoneal mesothelioma in patients who underwent debulking surgery. Materials and methods: The history, clinical and laboratory data, and imaging studies of 13 patients with histologically proven diagnosis of Malignant Peritoneal Mesothelioma (MPM) and their recurrence following cytoreductive surgery were reviewed. CT studies were reviewed for presence of ascites, peritoneal, mesenteric and omental involvement, presence of solid abdominal viscera involvement, gastrointestinal involvement, presence and location of enlarged lymph nodes and extra abdominal sites of involvement. Results: The most common finding at recurrence was ascites (n = 6). Peritoneal thickening was seen in five patients, infiltration of the peritoneum resembling omental caking was seen in one patient, and low density implants mimicking pseudomyxoma peritonei was seen in another patient. None of the peritoneal implants showed calcification. Three patients had large discrete soft tissue masses in the omentum and/or peritoneum. Multifocal serosal implants were seen in four patients; one had low grade small bowel obstruction which was managed conservatively. Three patients had evidence of intrathoracic disease seen as soft tissue pericardial mass and malignant pleural effusions. Conclusion: CT findings of recurrent MPM resemble primary MPM, metastatic or granulomatous diseases. Radiologist should be aware of its appearance and forms of recurrence which may be seen at extra abdominal sites.