An Uncommon Intramedullary Surprise: Pediatric Dorsal Epidermoid Tumor

Epidermoid tumors are benign epithelial-lined cysts filled with keratin. They are commonly seen in intracranial lesions, but their occurrence in the spine is very rare. They account for <1% of all intraspinal tumors. They are classified into two types: congenital or acquired. Most of the epidermoids are intradural extramedullary. Intramedullary epidermoids are very uncommon. A 15-year-old boy presented with a 6-month history of progressive lower-limb weakness without sensory loss, bladder involvement, or prior spinal procedures. Magnetic resonance imaging (MRI) of the dorsal spine revealed an intramedullary lesion with variable intensities on T2, noncontrast-enhancing, oval-shaped at D4–D5. The patient underwent D4–D5 laminectomy and microsurgical excision of the lesion. Intraoperatively, a pearly white, avascular, well-demarcated cyst containing keratinous material was noted. Histopathology confirmed a squamous epithelial-lined cyst consistent with an epidermoid cyst. Postoperatively, the patient showed complete neurological recovery, and a follow-up MRI at 6 months demonstrated total excision with no recurrence. Pediatric intramedullary epidermoid tumors are exceedingly rare entities that may mimic other intramedullary tumors. MRI with diffusion-weighted imaging is crucial for diagnosis. Microsurgical excision, aiming for complete capsule removal, remains the treatment of choice and offers an excellent prognosis.