A 39-year old Congolese native presented with a ten-year history of myalgia and progressive muscle weakness. He had a known tissue diagnosis of pulmonary, mediastinal and hepatic sarcoidosis, as well as latent tuberculosis. Family history was unavailable. Examination revealed deformity of the distal joints; shoulder girdle and proximal lower limb atrophy; proximal muscle weakness and a waddling gait. CK was 2560 IU/l (normal <290). Plain films of the hands revealed cystic bony change. EMG demonstrated features consistent with a necrotising myopathy. MRI of proximal muscle groups revealed abnormal high signal consistent with myositis. Biopsy of quadriceps was abnormal but failed to demonstrate features consistent with inflammation. A second biopsy targeted the deltoid- again no convincing evidence of inflammation was present; no granulomata were detected; the possibility of an underlying inherited myopathy was queried. The patient continued to experience progressive muscle symptoms. A third muscle biopsy of the contralateral deltoid was ultimately diagnostic, demonstrating a number of non-caseating granulomata.
Symptomatic sarcoid myopathy is rare, although the literature suggests high rates of asymptomatic muscle involvement. Securing an accurate diagnosis in this case was essential in order to guide appropriate use of immunosuppression. The clinical features and management of sarcoid myopathy are reviewed.