Diffuse malignant peritoneal mesothelioma presenting as small bowel obstruction

Mesotheliomas are aggressive malignant tumors which can occur most commonly in the pleural space, however can occur in the peritoneum in those with an extensive history of asbestos exposure. Primary peritoneal mesothelioma is relatively rare and is a fatal diagnosis. The prognosis of primary peritoneal mesothelioma is very poor and individuals are at high risk of developing mesothelioma in another cavity within the first year after initial diagnosis. Herein, we present a case of primary peritoneal mesothelioma, presenting as small bowel obstruction.

Pleurectomy and decortication are associated with better survival for bicavitary cytoreductive surgery for mesothelioma compared with extrapleural pneumonectomy

OBJECTIVES

Mesothelioma is a nearly uniformly fatal tumor. Multimodality therapy including cytoreductive surgery and chemotherapy is associated with long-term survival in some patients. Cytoreductive surgery for thoracic disease includes a lung-sparing operation called an "extended pleurectomy/decortication" or a lung-sacrificing surgery called an "extrapleural pneumonectomy." The benefit of cytoreductive surgery for bicavitary disease (chest and abdomen) is poorly understood. Our objective was to evaluate the long-term survivals for patients undergoing cytoreductive surgery for bicavitary disease and to determine whether any prognostic factors were associated with outcome.

METHODS

We reviewed our Institutional Review Board-approved, institutional, International Association for the Study of Lung Cancer Mesothelioma Staging Project database. Inclusion criteria were all patients who underwent cytoreductive surgery for bicavitary disease. Overall survival was calculated by Kaplan-Meier methodology. All International Association for the Study of Lung Cancer database elements were evaluated by univariable analysis.

RESULTS

From February 2014 to August 2021, 440 patients with mesothelioma were evaluated. Fourteen patients (3%) underwent cytoreductive surgery of both chest and abdomen as a planned 2-stage operation. Most patients (13/14; 93%) underwent chest surgery before abdomen surgery. For the entire cohort, the median overall survival was 33.6 months with a 5-year survival of 20%. Extended pleurectomy/decortication was associated with a better outcome compared with extrapleural pneumonectomy, with median overall survivals of 58.2 versus 13.5 months, respectively.

CONCLUSIONS

For a highly selected group of patients with bicavitary mesothelioma, long-term survival can be achieved with an aggressive, staged surgical approach. The patients who undergo extended pleurectomy/decortication with preservation of the lung appear to have more favorable outcomes compared with patients undergoing extrapleural pneumonectomy.

Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases

Malignant peritoneal mesothelioma historically carried a grim prognosis, but outcomes have improved substantially in recent decades. The prognostic significance of clinical, morphologic, and immunophenotypic features remains ill-defined. This multi-institutional cohort comprises 225 malignant peritoneal mesotheliomas, which were assessed for 21 clinical, morphologic, and immunohistochemical parameters. For epithelioid mesotheliomas, combining nuclear pleomorphism and mitotic index yielded a composite nuclear grade, using a previously standardized grading system. Correlation of clinical, morphologic, and immunohistochemical parameters with overall and disease-free survival was examined by univariate and multivariate analyses. On univariate analysis, longer overall survival was significantly associated with diagnosis after 2000 (P = 0.0001), age <60 years (P = 0.0001), ECOG performance status 0 or 1 (P = 0.01), absence of radiographic lymph-node metastasis (P = 0.04), cytoreduction surgery (P < 0.0001), hyperthermic intraperitoneal chemotherapy (P = 0.0001), peritoneal carcinomatosis index <27 (P = 0.01), absence of necrosis (P = 0.007), and epithelioid histotype (P < 0.0001). Among epithelioid malignant mesotheliomas only, longer overall survival was further associated with female sex (P = 0.03), tubulopapillary architecture (P = 0.005), low nuclear pleomorphism (P < 0.0001), low mitotic index (P = 0.0007), and low composite nuclear grade (P < 0.0001). On multivariate analyses, the low composite nuclear grade was independently associated with longer overall and disease-free survival (P < 0.0001). Our data further clarify the interactions of clinical and pathologic features in peritoneal mesothelioma prognosis and validate the prognostic significance of a standardized nuclear-grading system in epithelioid malignant mesothelioma of the peritoneum.

Two-Stage Cytoreductive Surgery and Intraperitoneal Chemotherapy for Diffuse Malignant Peritoneal Mesothelioma: Predictors of Overall Survival in an Intention-to-Treat Series

PURPOSE

Cytoreductive surgery with intraoperative hyperthermic intraperitoneal chemotherapy is standard of care for diffuse malignant peritoneal mesothelioma (DMPM), but there is variability among institutions in the administration of adjuvant chemotherapy. Characterization of the largest series of DMPM patients treated at a single institution and identification of the demographic, disease, and treatment factors associated with overall survival were sought.

PATIENTS AND METHODS

All DMPM patients who underwent initial cytoreductive surgery with the intention to undergo intraperitoneal chemotherapy and a second-look operation from 1995 to 2016 at our institution were retrospectively reviewed. The primary endpoint was overall survival.

RESULTS

A total of 204 DMPM patients underwent initial cytoreduction. Median overall survival was 32 months from initial cytoreduction. Independent baseline prognostic factors of improved overall survival were female sex, age < 60 years, and epithelioid histology. Independent treatment factors associated with improved overall survival were attempted resection at initial operation, residual disease < 0.5 cm at the end of the initial operation, and dwell intraperitoneal chemotherapy.

CONCLUSIONS

Cytoreductive surgery with intraoperative and dwell intraperitoneal chemotherapy is a feasible approach for DMPM. Expanded access to these therapies may offer benefit to a larger population of patients. Demographic and operative parameters associated with overall survival in this large cohort are consistent with previous reports. In the context of this treatment protocol, dwell intraperitoneal chemotherapy is associated with longer overall survival.