F-18 FDG PET/CT Detection of Mediastinal Malignancy in a Patient With Dermatomyositis

Dermatomyositis (DM) is an inflammatory myopathy that in adults is strongly associated with malignancy. The authors present a case of a man with dermatomyositis in which PET/CT imaging revealed diffuse proximal muscle hypermetabolism in keeping with the inflammatory nature of DM and was instrumental in the diagnosis of an underlying adenocarcinoma involving the mediastinum. Whole body PET/CT imaging may offer clinicians and patients an alternative to lengthy investigations in the search for occult malignancy.