Pancreatic Adenocarcinoma Presented as Paraneoplastic Dermatomyositis Complicated with Rhabdomyolysis: Case Report and Review.

BACKGROUND Dermatomyositis is a rare autoimmune condition characterized primarily by proximal muscle weakness and cutaneous rashes, such as Gottron's papules and heliotrope rash, and is classified as a subtype of idiopathic inflammatory myopathies. While the clinical spectrum of dermatomyositis is broad, its initial onset as fulminant rhabdomyolysis (complicated by acute renal failure) is exceedingly rare. Such atypical presentations necessitate proactive clinical vigilance to ensure a prompt and accurate diagnosis. CASE REPORT Our patient was a 53-year-old woman who presented with progressive proximal muscle weakness, dysphagia, dysphonia, elevated creatinine kinase levels, hyperkalemia, and renal impairment. She was initially treated for rhabdomyolysis; however, due to increasing creatinine kinase levels and renal impairment, she required hemodialysis. During hospitalization she developed characteristic skin manifestations, including heliotrope rash and sleeve sign. Further investigation revealed pancreatic adenocarcinoma of the pancreatic head. CONCLUSIONS This report underscores the diagnostic difficulties in differentiating paraneoplastic-associated dermatomyositis from isolated primary rhabdomyolysis. It emphasizes the imperative of screening for occult malignancies in adult patients presenting with profound muscle necrosis and secondary kidney impairment. Identifying unusual clinical patterns of dermatomyositis early, combined with the rapid initiation of immunosuppressant and rigorous cancer surveillance, is essential for improving prognosis. This becomes paramount in scenarios in which the clinical presentation is suggestive of a paraneoplastic origin, notably pancreatic malignancy.