A case of malignant peritoneal mesothelioma suggesting the utility of combining double-contrast radiography and endoscopy with computed tomography for diagnosis

Localized biphasic malignant mesothelioma presenting as a giant pelvic wall mass: a rare case report and literature review

Background

Localized biphasic MPeM is rare in clinical practice, we reviewed 8 cases of localized biphasic MPeM (including our present case), and summarized the clinical and imaging features of the disease.

Case presentation

We reported a 79-year-old man with chief complaint of a narrowing in the caliber of the stool for one year. A soft tissue shadow was occasionally found by CT examination in the right pelvic wall, and it was diagnosed as localized biphasic malignant peritoneal mesothelioma (MPeM) by postoperative pathology. Radical excision was performed and no radio-chemotherapy was applied. Nearly six years after surgery, the mass was significantly enlarged, and the neighboring tissues including rectum, prostate, seminal vesicle, and right ischial ramus were all infiltrated. The patient was in the end stage of cancer with poor prognosis.

Conclusions

The localized biphasic MPeM may show following characteristics: (1) with heterogeneous low-density and obscure margin; (2) with low incidence rate of ascites; (3) with few central hemorrhage and necrosis; (4) with few calcified structures; (5) with mild to moderate heterogeneous delayed enhancement on contrast-enhanced CT. The imaging characteristics can provide further information for the diagnosis of localized biphasic MPeM in the future.

Malignant Peritoneal Mesothelioma Presenting as Mucinous Ascites

We present a rare case of a 46-year-old man presenting with mucinous ascites secondary to malignant peritoneal mesothelioma (MPM) that was diagnosed via colonoscopy with biopsies. Both our findings and the clinical presentation were unique. While it is widely known that asbestos exposure is commonly associated with pleural mesothelioma, 6-10% of malignant mesotheliomas arise from the peritoneum. To date, only 4 cases of MPM with the primary tumor site in the colon have been described in the literature.