Paraneoplastic Anti-Tif1-gamma Autoantibody-positive Dermatomyositis as Clinical Presentation of Hepatocellular Carcinoma Recurrence.

Hepatocellular carcinoma (HCC) is rarely associated with autoimmune paraneoplastic syndromes. We report a case of anti-transcriptional intermediary factor-1 gamma (TIF1-γ)-positive dermatomyositis (DM) as clinical presentation of HCC recurrence in a 72-year-old male patient admitted to our hospital due to fatigue, myalgia, and typical skin rash. His medical history was notable for hepatitis C-related cirrhosis, successful treatment with direct-acting antiviral agents, and previously efficacious treatment of HCC. Laboratory testing showed significant rhabdomyolysis with anti-TIF1-γ antibodies at high titer, and DM was diagnosed. After a careful diagnostic workup, HCC recurrence was diagnosed. After first-line corticosteroid treatment, azathioprine and intravenous immunoglobulin treatments were administered; unfortunately, he mounted only partial response. Owing to the compromised performance status, no HCC treatment was feasible, and, according to international guidelines, he received only best supportive care. Here, we discuss the diagnostic, prognostic, and pathogenic roles of anti-TIF1-γ antibodies associated with paraneoplastic DM and the scant literature data on its occurrence in HCC patients. Considering the TIF1 gene family's established role in oncogenesis, we also review the role of TIF1-γ as a tumor-related neoantigen, leading to the development of clinically overt anti-TIF1-γ antibodies-positive DM.