18F-FDG PET/CT Useful for the Early Detection of Rapidly Progressive Fatal Interstitial Lung Disease in Dermatomyositis

Interstitial lung disease (ILD) frequently accompanies polymyositis (PM) and dermatomyositis (DM) and is a major cause of mortality. The rapid diagnosis of ILD is paramount. However, the early changes of presymptomatic ILD are difficult to detect. We present a patient with DM who had positive uptake in the lung of FDG-PET/CT as well as 'mechanic's hands' appearance, increased serum ferritin and serum anti-CADM-140 antibody, all before the detection of ILD by CT. Although aggressive treatment was initiated, the patient died of diffuse alveolar damage. These observations suggest that the pulmonary uptake of 18F-FDG predicts rapidly progressive ILD in DM.