FDG PET/CT Findings of a Small Cell Carcinoma of the Lung Presented as Diffuse Dermatomyositis

ABSTRACT: Patients with dermatomyositis are prone to have occult malignancy. A previously healthy 68-year-old man with dermatomyositis underwent FDG PET/CT to detect possible malignancy of unknown origin. The images showed not only diffuse increased activity in the muscle, which was related to the known dermatomyositis, but also intense activity in the anterior chest with foci of abnormal activity throughout the body. Pathology examination confirmed small cell carcinoma of the lung with widespread metastases.