具有临床意义的单克隆丙种球蛋白病(MGCS)相关的肌病是一组基于肌肉MGCS的罕见表现。它主要包括淀粉样蛋白轻链(AL)淀粉样变性和散发性晚发性线虫性肌病,其单克隆丙种球蛋白病意义不明。当肌病表现为最初或唯一的临床症状时,它通常可以延迟或误诊为其他肌病。我们报告了一名60岁男子的病例,该男子最初表现为对称近端下肢的疲劳和肌肉无力。肌肉活检未显示单核细胞浸润,萎缩,坏死,或刚果红染色结果阳性。血清蛋白电泳和免疫固定电泳结果均为阴性。没有建立特异性诊断。一年后,在进行心肌和脂肪垫活检后,患者被诊断为AL淀粉样变性,在重新评估后,肌病被诊断为AL淀粉样变性相关肌病.患者接受CyBorD方案化疗,并获得血液学和器官缓解。因此,我们回顾了MGCS相关肌病的临床和病理表现。根据已发表的文章和本案,我们得出的结论是,在原因不明的肌病中全面筛查MGCS对于避免误诊或延误诊断至关重要.
Monoclonal gammopathies of clinical significance (
MGCS)-associated myopathy is a group of muscular
MGCS-based rare manifestations. It mainly includes amyloid light chain (AL) amyloidosis and sporadic late-onset nemaline myopathy with monoclonal gammopathy of undetermined significance. When myopathy manifests as the initial or sole clinical symptom, it can often be delayed or misdiagnosed as other myopathies. We report the
case of a 60-year-old man who initially presented with fatigue and muscle weakness of the symmetric proximal lower limbs. Muscle biopsy did not reveal mononuclear cell infiltration, atrophy, necrosis, or positive Congo red staining results. The results of serum protein electrophoresis and immunofixation electrophoresis were negative. No specific diagnosis was established. After 1 year, the patient was diagnosed with AL amyloidosis after myocardial and fat pad biopsies were performed and myopathy was diagnosed as AL amyloidosis-associated myopathy after reassessment. The patient received CyBorD regime chemotherapy and achieved hematological and organ remission. Therefore, we reviewed the clinical and pathological manifestations of
MGCS-associated myopathies. Based on published articles and the present
case, we conclude that comprehensive screening for
MGCS in unexplained myopathy is essential to avoid misdiagnosis or delayed diagnosis.