Unusual appearance of malignant peritoneal mesothelioma

The role of imaging in diagnosis and management of malignant peritoneal mesothelioma: a systematic review

PURPOSE

Imaging of the peritoneum and related pathology is a challenge. Among peritoneal diseases, malignant peritoneal mesothelioma (MPeM) is an uncommon tumor with poor prognosis. To date, there are no specific guidelines or imaging protocols dedicated for the peritoneum and MPeM. The objective of this study was to analyze the literature describing imaging modalities used for MPeM to determine their relative clinical efficacy and review commonly reported imaging features of MPeM to promote standardized reporting.

METHODS

We performed a systematic review of original research articles discussing imaging modalities in MPeM from 1999 to 2020. Effectiveness measures and common findings were compared across imaging modalities.

RESULTS

Among 582 studies analyzed, the most-used imaging modality was CT (54.3%). In the differentiation of MPeM from peritoneal carcinomatosis, one study found CT had a diagnostic sensitivity of 53%, specificity of 100%, and accuracy of 68%. Two studies found fluorodeoxyglucose positron emission tomography (FDG-PET) had sensitivity of 86-92%, specificity of 83-89%, and accuracy of 87-89%. Another study found magnetic resonance imaging (MRI) was the best predictor of the peritoneal carcinomatosis index. Characteristics shown to best differentiate MPeM from other diseases included ascites, peritoneal thickening, mesenteric thickening, pleural plaques, maximum tumor dimension, and number of masses.

CONCLUSION

Most published MPeM imaging studies utilized CT. PET/CT or MRI appear promising, and future studies should compare effectiveness of these modalities. MPeM imaging reports should highlight ascites, number of and maximum tumor dimension, peritoneal/mesenteric thickening, and associated pleural plaques, allowing for better aggregation of MPeM imaging data across studies.

Significant Clinical Benefit of Pemetrexed-based Chemotherapy for Advanced Diffuse Malignant Peritoneal Mesothelioma: A Case Presentation

Diffuse malignant peritoneal mesothelioma (DMPM) is generally an understudied disease, largely because most molecular and clinical studies of mesothelioma have been conducted in patients with the more common malignant pleural mesothelioma. We present the case of a 45-year-old male that initially presented with abdominal discomfort and ascites. Diagnostic workup revealed advanced DMPM. Bimodal treatment was stared with cytoreductive surgery and hyperthermic intraperitoneal perfusion with chemotherapy procedure, followed by pemetrexed systemic monotherapy. After the disease progression, and because of a very good previous treatment response to pemetrexed, we decided to rechallenge systemic pemetrexed, along with the introduction of cisplatin. Although the intent behind systemic treatment was at first solely palliative, overall survival after the initial diagnosis was 50 months. Treatment based on rechallenging pemetrexed with or without cisplatin in patients with advanced DMPM can result in a quite satisfactory disease control and symptom management.