Fatal Viral Rhombencephalitis Mimicking Acute Necrotizing Encephalitis in a Young Female: An Autopsy Case Report

Sudden death due to rhombencephalitis is a rare and life-threatening inflammatory condition, infrequently reported in forensic literature. Rhombencephalitis and acute necrotizing encephalitis (ANE) are uncommon but severe inflammatory disorders of the central nervous system, often linked to viral infections. Both may present with seizures, altered sensorium, and rapid neurological deterioration leading to fatal outcomes. We describe the case of an 18-year-old previously healthy female who developed high-grade fever followed by seizures and progressive encephalopathy. Neuroimaging showed diffuse cerebral edema with bilateral thalamic hyperintensities, raising the possibility of ANE, complicated by intracranial circulatory arrest. Despite supportive measures, the patient succumbed within 24 hours. Histopathologic examination revealed lymphocytic infiltration of the brainstem, pontine microhemorrhages, and absent thalamic necrosis, favoring viral rhombencephalitis rather than necrotizing encephalitis. This case illustrates the clinicoradiological overlap between rhombencephalitis and ANE and highlights the diagnostic and medicolegal challenges in sudden deaths due to fulminant viral encephalitic syndromes.