Benzerdjeb N, Dartigues P, Kepenekian V, et al. - Given survival in patients with epithelioid malignant pleural mesothelioma was predicted by a recently described nuclear-grading system, researchers herein intended to validate this grading system in epithelioid malignant peritoneal mesothelioma (EMPM) as well as tried to compare with combined grade, including nuclear atypia, mitotic count, and tumor necrosis. They analyzed cases of EMPM. They assessed another system combining nuclear atypia score, mitotic score, and tumor necrosis and this system was defined as a combined grade I–III. They found 138 cases. The best overall and progression-free survivals were experienced by patients with combined grade I tumors vs nuclear grade I. According to findings of this large multicentric study, the best independent predictors of OS and PFS in EMPM were: combined grade and nuclear grade. Pathologists engaged in the management of malignant peritoneal mesothelioma should readily describe these systems owing to their potential therapeutic implications.