Subacute anterior spontaneous spinal epidural hematoma at the thoracolumbar junction: A diagnostic confounder following necrotizing staphylococcal pneumonia.

Spontaneous spinal epidural hematoma (SSEH) is a rare cause of acute spinal cord compression, accounting for less than 1% of spinal space-occupying lesions. Its ventral localization is exceptionally uncommon due to the firm adherence of the dura to the posterior longitudinal ligament. We report the case of a 61-year-old woman with type 1 diabetes and a remote history of necrotizing Staphylococcus aureus pneumonia (treated 5 months prior) who presented with a 1-week history of progressive paraparesis and marked biological inflammatory markers (Leukocytes: 19,800/mm³; Eosinophils: 6800/mm³). A multimodal radiological evaluation was performed. Chest CT revealed a sequelar right apical cavity, while brain MRI was unremarkable. Spinal MRI demonstrated a D11-L1 anterior biconvex epidural collection (hyperintense on T1 and hypointense on T2-weighted images), associated with L4-S1 intrathecal hematic infiltration. These findings are pathognomonic for intracellular methemoglobin in a late subacute hematoma. Despite the pulmonary cavity and the biological "red herrings," MRI signal analysis correctly ruled out a late-onset epidural abscess. Emergency laminectomy confirmed the diagnosis, and the patient showed significant recovery at 3 months. This case highlights the role of MRI biophysics in deconstructing diagnostic traps and the importance of recognizing the methemoglobin signature in complex clinical scenarios.