18F-FDG PET/CT and MRI in Necrotizing Autoimmune Myopathy: “The Scarface Sign”
Necrotizing autoimmune myopathy (NAM) is a relatively newly recognized subgroup of idiopathic inflammatory myopathies. The common histopathologic features are myocyte necrosis without significant inflammation. Necrotizing autoimmune myopathy can be associated with connective tissue disorders but can also be triggered by viral infections such as human immunodeficiency virus or malignancy, be statin-induced NAM, or be idiopathic. Here, the authors present the case of a 58-year-old man who was referred to our PET unit for a suspected paraneoplastic syndrome in a context of NAM. Complementary contrast-enhanced CT and 3-dimensional T1-weighted MRI were carried out subsequently in order to resolve the PET/CT abnormalities.