Herpes simplex encephalitis (HSE) is the most common type of sporadic encephalitis that inflicts high rates of morbidity and mortality. Differentiating a progressing encephalitis syndrome from a lobar hemorrhage as a complication presents a challenge and requires great vigilance and insight on part of the treating physician.

Facial puffiness as a consequence of superior vena cava syndrome (SVCS), can be a presentation from which the physician would have to conjecture a diagnosis of a mediastinal mass including lymphomas. Pediatric SVCS can rapidly progress and pose a greater challenge for airway protection as was in our case.