A severe case of subacute sarcoid myositis.

A 46-year-old woman presented progressive proximal weakness and dysphagia. Her serum creatine kinase and myoglobin levels were markedly elevated. Chest X-rays revealed bilateral swelling of the hilar lymph nodes. Needle electromyography demonstrated active denervation and early recruitment. MRI of her skeletal muscle showed focal high intensities on T1-weighted images that were associated with diffusely increased signal intensities on T2-weighted images. Muscle biopsy revealed infiltration of inflammatory cells associated with non-caseating granulomas, and there was widespread segmental fiber necrosis, where necrotic fibers appeared regardless of these granulomas. Immunohistochemical analysis of the surface markers of the infiltrating cells showed CD68- and CD4-positive cells infiltrating into the central area of the granuloma, while CD8-positive cells infiltrating into the endomysium and the periphery of the granulomas. The characteristic histology of the granuloma confirmed the diagnosis of sarcoidosis. The diffuse muscle pathology was consistent with the patient's severe clinical course.