Accardi Fabrizio, Papa Valentina, Capozzi Anna Rita, Capello Gian Luca, Verga Laura, Mancini Cristina, Martella Eugenia, Costa Roberta, Notarfranchi Laura, Dalla Palma Benedetta, Aversa Franco, Pietrini Vladimiro, Cenacchi Giovanna, Giuliani Nicola
UO di Ematologia e CTMO, Azienda Ospedaliero-Universitaria di Parma and Department of Medicine and Surgery, University of Parma, Parma, Italy.
Department of Biomedical and Neuromotor Sciences, Alma Mater University of Bologna, Bologna, Italy.
Case Rep Hematol. 2018 Jan 31;2018:9840405. doi: 10.1155/2018/9840405. eCollection 2018.
Muscle involvement in AL amyloidosis is a rare condition, and the diagnosis of amyloid myopathy is often delayed and underdiagnosed. Amyloid myopathy may be the initial manifestation and may precede the diagnosis of systemic AL amyloidosis. Here, we report the case of a 73-year-old man who was referred to our center for a monoclonal gammopathy of undetermined significance (MGUS) diagnosed since 1999. He reported a progressive weakness of proximal muscles of the legs with onset six months previously. Muscle biopsy showed mild histopathology featuring alterations of nonspecific type with a mixed myopathic and neurogenic involvement, and the diagnostic turning point was the demonstration of characteristic green birefringence under cross-polarized light following Congo red staining of perimysial vessels. Transmission electron microscopy (TEM) confirmed amyloid fibrils around perimysial vessels associated with collagen fibrils. A stepwise approach to diagnosis and staging of this disorder is critical and involves confirmation of amyloid deposition, identification of the fibril type, assessment of underlying amyloidogenic disorder, and evaluation of the extent and severity of amyloidotic organ involvement.
肌肉受累于AL型淀粉样变性是一种罕见情况，淀粉样变肌病的诊断常常延迟且诊断不足。淀粉样变肌病可能是首发表现，且可能先于系统性AL型淀粉样变性的诊断出现。在此，我们报告一例73岁男性病例，该患者自1999年起被诊断为意义未明的单克隆丙种球蛋白病（MGUS），并转诊至我院。他自述6个月前开始出现进行性腿部近端肌肉无力。肌肉活检显示轻度组织病理学改变，具有非特异性类型的改变，伴有混合性肌病和神经源性受累，诊断的转折点是在刚果红染色的肌束膜血管在偏振光下呈现特征性的绿色双折射。透射电子显微镜（TEM）证实肌束膜血管周围存在与胶原纤维相关的淀粉样纤维。对于这种疾病，采用逐步诊断和分期方法至关重要，这包括确认淀粉样沉积、识别纤维类型、评估潜在的淀粉样变性疾病以及评估淀粉样变性器官受累的范围和严重程度。
