Clinical Practice and Cases in Emergency Medicine

Introduction: Caused by portosystemic venous shunting, the focal hepatic hot spot sign (or hot quadrate sign) is a radiologic finding most commonly associated with superior vena cava (SVC) obstruction. On contrast-enhanced imaging, this finding may mimic active hepatic extravasation or focal hepatic pathology, posing a diagnostic challenge in the emergency department (ED). 

Case Report: We report a case of a 70-year-old man with progressive cognitive decline and hypoxemic respiratory failure requiring intubation. Computed tomography (CT) angiography of the chest demonstrated a focal area of intense contrast enhancement in the left hepatic lobe, initially concerning for active extravasation. Further review of the imaging revealed a right upper lobe lung mass and a large mediastinal mass causing high-grade SVC stenosis. The hepatic finding was subsequently identified by the reading radiologist as a focal hepatic hot spot sign representing a vascular pseudolesion due to collateral venous flow. The patient was diagnosed with SVC syndrome secondary to malignancy and underwent chemotherapy before transitioning to comfort care. 

Conclusion: The focal hepatic hot spot sign represents a hepatic pseudolesion resulting from altered venous return and collateral circulation, most commonly in the setting of SVC obstruction. In the ED, this finding may be misinterpreted as hemorrhage or focal hepatic pathology, potentially leading to unnecessary diagnostic or therapeutic interventions. Recognition of the focal hepatic hot spot sign is essential for emergency physicians to avoid misdiagnosis and identify underlying central venous obstruction. Awareness of this imaging pitfall can improve diagnostic accuracy and guide appropriate management in patients undergoing contrast-enhanced CT imaging.