Abstract
A muscle biopsy remains the golden standard in the diagnosis of dermatomyositis/polymyositis(PM/DM) in spite of its invasiveness. But a biopsy specimen does not always reflect the presence of inflammation because the distribution of muscle lesions is frequently patchy, so selection technique should be used to guide for biopsy of the representative sample.［18F］fluorodeoxyglucose positron emission tomography/computed tomography(FDG-PET/CT) is a nuclear medicine technique that detects increased uptake of FDG by metabolically active cells at sites of neoplasm, infection, and in inflammation and has been used in the management of PM/DM recently. We report here a 40-year-old woman who was diagnosed with polymyositis by FDG-PET/CT-guided biopsy of the greater pectoral muscle.
She was admitted to our hospital because of arthralgia and elevation of her serum creatine kinase(CK). She had little myalgia and denied muscle weakness of four proximal limbs. We performed FDG-PET/CT for the screening of malignant neoplasms and found the accumulation of FDG in both greater pectoral muscles. The biopsy of right greater pectoral muscle was done and showed infiltration of inflammatory cells. Also, computerized tomography and FDG-PET /CT of lungs showed consolidation and subpleural opacities and the accumulation of FDG in both lungs, so she was diagnosed as polymyositis with active interstitial pneumonia and was treated with prednisolone(50mg/day) and tacrolimus(2mg/day), which was proved to be effective.
