Abstract
Background. Nephrotic syndrome is frequently observed as paraneoplastic syndrome in the patients with malignant disease. However, malignant pleural mesothelioma with nephrotic syndrome is rare. The therapeutic approaches for malignant pleural mesothelioma with nephrotic syndrome are not yet well established. Case. A 65-year-old man was admitted with dyspnea on exertion due to the left pleural effusion. A video-assisted thoracoscopic surgical pleural biopsy failed to make a diagnosis. Five months later, he was admitted to our hospital with abdominal pain and systemic edema, and was diagnosed as having nephrotic syndrome with massive proteinuria (36.6 g/day). A kidney biopsy revealed that the cause of nephrotic syndrome was membranous nephropathy and he was treated with high-dose steroids. It was suspected that his condition was complicated with a malignancy and PET-CT showed the accumulation of 18F-FDG in the thick pleura on the left mediastinum side. He underwent open pleural biopsy and was diagnosed with epithelial malignant pleural mesothelioma. He could not undergo surgical resection due to his low serum albumin level and because he had been treated with high-dose steroids; he therefore received chemotherapy. After 5 cycles of chemotherapy, his serum albumin level improved and his dose of steroids had decreased, thereby enabling pleurectomy/decortication. The patient's serum albumin level and proteinuria were further improved after the surgical resection of the tumor. Conclusion. We experienced a case of malignant pleural mesothelioma with paraneoplastic nephrotic syndrome, which was improved by chemotherapy and surgical resection.
