Sporadic late-onset nemaline myopathy (SLONM) is a rare, acquired muscle disease presenting with subacute progression in adulthood. It can be accompanied by a monoclonal gammopathy of undetermined significance (MGUS). We describe clinical and histopathological findings of four SLONM patients with MGUS. In all patients, nemaline rod, inter-myofibrillary network disruption, atrophic changes, peripheral basophilic discoloration, vacuole without rim, and cytoplasmic body without inflammation were seen. Three out of four patients were treated with prednisolone in combination with IVIG monthly and had an appropriate response to the treatment. The optimal first-line treatment remains unclear in SLONM-MGUS, although corticosteroids plus IVIg is associated with favorable clinical response. These treatment modalities might be used as an optional treatment before autologous stem cell transplantation; however, further studies with a higher number of patients are required.

中文翻译：

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散发性迟发性线状体肌病伴未确定意义的单克隆丙种球蛋白病：四名患者的报告

散发性迟发性线状体肌病 (SLONM) 是一种罕见的获得性肌肉疾病，在成年期表现为亚急性进展。它可伴有意义未明的单克隆丙种球蛋白病 (MGUS)。我们描述了四名患有 MGUS 的 SLONM 患者的临床和组织病理学发现。所有患者均可见线状体棒状、肌原纤维间网络破坏、萎缩性改变、外周嗜碱性变色、空泡无缘、胞质体无炎症。四分之三的患者每月接受泼尼松龙联合 IVIG 治疗，并且对治疗有适当的反应。尽管皮质类固醇加 IVIg 与良好的临床反应相关，但 SLONM-MGUS 的最佳一线治疗仍不清楚。这些治疗方式可用作自体干细胞移植前的可选治疗；然而，还需要对更多患者进行进一步研究。