Delayed Diagnosis of Thyroid Storm Presenting With Predominant Gastrointestinal Symptoms.

Thyroid storm is a rare but life-threatening endocrine emergency. Although mortality predictors have been described, diagnostic delay remains under-recognized, particularly in atypical presentations. A previously healthy man in his 20s presented with persistent nausea, vomiting, diarrhea, and 5-kg weight loss over one month. Abdominal computed tomography suggested superior mesenteric artery (SMA) syndrome. Despite supportive treatment, symptoms fluctuated and subsequently worsened with hemodynamic instability. Thyroid function tests performed during readmission revealed markedly elevated free thyroid hormone levels with suppressed TSH. He fulfilled diagnostic criteria for thyroid storm. Despite intensive treatment including antithyroid drugs, beta-blockade, corticosteroids, mechanical ventilation, and extracorporeal membrane oxygenation, he died from progressive multiorgan failure. Thyroid storm may present predominantly with gastrointestinal symptoms and minimal classical features, leading to diagnostic anchoring on radiological findings. Early thyroid function testing should be considered in patients with persistent unexplained gastrointestinal symptoms accompanied by systemic deterioration.