Abstract
BACKGROUND: Pleural mesothelioma, characterized by a dismal prognosis even with multimodal therapy, has seen emerging interest in immune checkpoint inhibitors (ICIs) due to their demonstrated efficacy. Here, we present a case of epithelioid-type pleural mesothelioma with chest wall invasion treated with definitive ICI therapy, resulting in a remarkable pretreatment effect. CASE PRESENTATION: A 46-year-old man was diagnosed with an abnormal chest shadow on a medical check, and a computed tomography scan showed pleural thickening at the dorsal right upper chest wall. One of the nodules was suspected to have invaded the chest wall. A needle biopsy revealed epithelioid-type pleural mesothelioma. After five cycles of nivolumab plus ipilimumab, he underwent right pleurectomy/decortication (P/D). Pathological examination revealed a significant treatment effect, showing numerous lymphocytes infiltrating the tumor nodule and viable tumor cells localized at approximately 6 mm. CONCLUSION: Although further accumulation of cases is required to evaluate the effectiveness and case selection, P/D after immunotherapy is a useful curative treatment option for advanced pleural mesothelioma.