Lymphohistiocytoid mesothelioma with a response to cisplatin plus pemetrexed: A case report

We report the case of a patient with lymphohistiocytoid mesothelioma (LHM) with a response to systemic chemotherapy consisting of cisplatin and pemetrexed. A 72-year-old man was referred to our hospital because of abnormal shadows seen on chest X-rays. He had been exposed to asbestos at shipyards for 3 years. Computed tomography (CT) images of the chest showed multiple masses on the parietal pleura, diaphragm, and the interlobar pleura of the right. CT-guided percutaneous needle biopsy was performed and the biopsy specimen demonstrated fibrous thickening of the pleura with abundant lymphocyte infiltration. Immunohistochemical analyses revealed that the cells were positive for calretinin, WT-1, and CAM5.2, and negative for CEA, TTF-1, CK5/6, AE1/AE3, desmin, CD3, CD20, CD30, and CD68. Based on these findings, the diagnosis was confirmed as LHM. Systemic chemotherapy consisting of cisplatin (75 mg/m²) and pemetrexed (500 mg/m²) was delivered. After 6 courses of chemotherapy, multiple tumors had remarkably regressed, and the patient remains on maintenance treatment with pemetrexed. There are few reports of chemotherapy for LHM. The combination of cisplatin and pemetrexed could be a good treatment option for LHM.