Department of Neurology, University of California San Francisco School of Medicine, San Francisco, California, USA.
Department of Pathology, University of California San Francisco, San Francisco, California, USA.
BMJ Case Rep. 2022 Jun 6;15(6):e246688. doi: 10.1136/bcr-2021-246688.
Giant cell myositis (GCM) is a rare inflammatory myopathy associated with myasthenia gravis and thymoma. Here, we report on a woman in her late 50s with a history of myasthenia gravis, systemic lupus erythematosus and stage IV thymoma with pleural metastases, who presented with proximal weakness, neuromuscular respiratory failure and hypercalcaemia. She was diagnosed with GCM via muscle biopsy and screened for myocarditis but showed no evidence of myocardial involvement. Her hypercalcaemia was consistent with a granulomatous process, likely driven by her GCM. Her strength gradually improved, and her hypercalcaemia did not recur after treatment with high dose steroids, intravenous immune globulin and plasma exchange. Her course was complicated by several opportunistic infections in the setting of her immunosuppression. Despite the high morbidity associated with GCM, she demonstrated clinical improvement after initiating immunosuppressive therapy and continues to be managed in the outpatient setting.
巨细胞肌炎（Giant cell myositis，GCM）是一种罕见的与重症肌无力（myasthenia gravis）和胸腺瘤相关的炎性肌病。在此，我们报告了一位 50 多岁的女性患者，她患有重症肌无力、系统性红斑狼疮和 IV 期胸腺瘤伴胸膜转移，表现为进行性近端肌无力、神经肌肉呼吸衰竭和高钙血症。通过肌肉活检和心肌炎筛查诊断为 GCM，但未发现心肌受累的证据。她的高钙血症符合肉芽肿性过程，可能由 GCM 引起。她的肌力逐渐改善，在接受大剂量类固醇、静脉注射免疫球蛋白和血浆置换治疗后，高钙血症未再复发。由于免疫抑制，她的病程中还并发了几次机会性感染。尽管 GCM 相关发病率高，但她在开始免疫抑制治疗后显示出临床改善，并继续在门诊接受治疗。
