MALIGNANT PERITONEAL MESOTHELIOMA (MPeM) is a rare disease that is difficult to diagnose pathologically because of nonsensitive cytological evaluation and difficulty in differentiating with other malignant diseases. Most MPeM cases are diagnosed using surgically resected specimens, and reports showing the usefulness of endoscopic ultrasound (EUS)-guided tissue acquisition for the diagnosis of MPeM and other peritoneal diseases are limited. Herein, we describe the usefulness of EUSguided fine-needle biopsy (EUS-FNB) for definitive diagnosis of MPeM. An 82-year-old woman was referred to our hospital for ascites work-up. She had no history of asbestos exposure. She underwent contrast-enhanced computed tomography, which showed no abdominal masses but revealed thickening of the peritoneum with a moderate amount of ascites (Fig. 1A,B); meanwhile, other organs did not manifest abnormality. Furthermore, extremely high levels of hyaluronic acid and cytokeratin fragment 21-1 were detected in ascitic fluid analysis by abdominocentesis; however, ascitic

中文翻译：

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内镜超声引导下细针活检对恶性腹膜间皮瘤的明确诊断

恶性腹膜间皮瘤（MPeM）是一种罕见的疾病，由于细胞学评估不敏感且难以与其他恶性疾病鉴别，因此难以病理诊断。大多数 MPeM 病例是使用手术切除的标本进行诊断的，显示内窥镜超声 (EUS) 引导的组织采集对 MPeM 和其他腹膜疾病诊断的有用性的报告是有限的。在此，我们描述了 EUS 引导细针活检 (EUS-FNB) 对 MPeM 确诊的有用性。一名 82 岁女性被转诊至我们医院进行腹水检查。她没有石棉接触史。她接受了对比增强计算机断层扫描，未显示腹部肿块，但显示腹膜增厚，并伴有中量腹水（图 1A、B）；同时，其他器官未见异常。此外，通过腹腔穿刺术在腹水分析中检测到极高水平的透明质酸和细胞角蛋白片段 21-1；然而，腹水