A Case of Malignant Pleural Mesothelioma with Paraneoplastic Nephrotic Syndrome Successfully Treated with Surgery Followed by Chemotherapy

━━ 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 videoassisted 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. (JJLC. 2016;56:342-348) KEY WORDS━━Nephrotic syndrome, Membranous nephropathy, Malignant pleural mesothelioma, Paraneoplastic syndrome Corresponding author: Naohiko Inase. Received March 18, 2016; accepted June 13, 2016. 要旨━━背景.ネフローゼ症候群はしばしば傍腫瘍性 症候群として発症することが知られているが,悪性胸膜 中皮腫にネフローゼ症候群を合併する症例の報告はわず かであり,治療指針は確立されていない.症例.65 歳男 性.労作時呼吸困難のため前医を受診し,左胸水が認め られた.胸腔鏡下胸膜生検を施行されたが診断はつかな かった.約 5か月後,腹痛と全身性浮腫を自覚し,当院 を受診した.36.6 g/日の大量の尿蛋白を認め,ネフロー ゼ症候群と診断した.腎生検で膜性腎症であり,高用量 ステロイド療法を行った.悪性腫瘍合併を疑われ,PETCTを撮像し,左胸膜縦隔側に 18F-FDG集積を認めた.同 部位の開胸生検により,上皮型悪性胸膜中皮腫と診断し た.ネフローゼ症候群に伴う低アルブミン血症のため手 術困難であり,化学療法とステロイドの投与を行った. 東京医科歯科大学医学部附属病院 1呼吸器内科,2呼吸器外科,3病 理部. 論文責任者:稲瀬直彦. 受付日:2016 年 3 月 18 日,採択日:2016 年 6 月 13 日. (肺癌.2016;56:342-348) 2016 The Japan Lung Cancer Society Malignant Pleural Mesothelioma with Nephrotic Syndrome Treated with Multidisciplinary Treatment―Hanzawa et al Japanese Journal of Lung Cancer―Vol 56, No 5, Oct 20, 2016―www.haigan.gr.jp 343 Table 1. The Laboratory Findings 【Hematology】 【Biochemistry】 【Serology】 WBC 5400/μl TP 4.1 g/dl IgG 475 mg/dl RBC 462/μl Alb 0.5 g/dl IgA 244 mg/dl Hb 14.5 g/dl BUN 18 mg/dl IgM 132 mg/dl Hct 44.6% Cre 1.3 mg/dl ANA <1:40 Plt 44.8/μl Na 144 mEq/l Anti-DNA Ab <2.0 IU/ml K 3.7 mEq/l MPO-ANCA <1.0 EU 【Coagulation】 Cl 112 mEq/l PR3-ANCA <1.0 EU PT-INR 1.16 Ca 7.1 mg/dl Anti-HBs Ab <1.0 APTT 48.7 sec AST 17 IU/l Anti-HCV Ab (-) D-dimer 3.55 μg/ml ALT 9 IU/l Cryoglobulin (-) LDH 210 IU/l CEA 1.8 ng/ml 【Urinalysis】 T-Cho 877 mg/dl CYFRA 1.0 ng/ml Protein 4+ HDL-Cho 30 mg/dl Occult blood 2+ LDL-Cho 712 mg/dl RBC 20-29/hpf CRP 0.45 mg/dl WBC 1-4/hpf Hyaline casts 3+/hpf Fatty casts 1+/hpf Selectivity index 0.255 化学療法 5コース施行後にネフローゼ症候群の改善を認 め,ステロイドを減量し,胸膜切除・肺剥皮術を施行し た.手術後に血清アルブミン値がさらに改善し,尿蛋白 量も改善した.結論.化学療法と手術によりネフローゼ 症候群の改善を認めた,悪性胸膜中皮腫の 1例を経験し た. 索引用語━━ネフローゼ症候群,膜性腎症,悪性胸膜中 皮腫,腫瘍随伴性症候群