Sacral Extradural Granular Cell Tumor: A Case Report With Electron Microscopy Findings

Granular cell tumors (GCTs) are rare neoplasms of Schwann cell origin, characterized by distinctive histopathological features. They most commonly occur in the head, neck, and upper digestive tract and rarely involve peripheral nerves, although immunohistochemistry and electron microscopy have, in some cases, confirmed a neural origin. A 33-year-old male presented with pain and paresthesia of the left lower limb for two years. MRI of the lumbosacral spine revealed an extradural lesion in the left S1 neural foramen. He underwent a left S1 hemilaminectomy and excision of the lesion. Histopathology, supported by immunohistochemistry and electron microscopy, confirmed a diagnosis of GCT. Histological confirmation is critical, as these lesions can radiologically mimic other tumors commonly found in this location, and treatment may need to be modified for more aggressive tumor subtypes.