Surgical nuances of intramedullary white epidermoid cyst in the conus medullaris: A rare entity

Abstract

Spinal epidermoid cysts (ECs) are benign slow-growing spinal tumors. The account for <1% of spinal tumors and are usually found intradural extramedullary. This report is regarding two rare cases of intramedullary white ECs present at the conus medullaris. In the first case, a 32-year-old male presented with a complaint of lower backache for 5 years, which progressively increased in intensity, radiating to the left leg. The patient had left lower limb weakness in the form of difficulty in walking. On examination, power of left knee and ankle was 4/5. Left extensor hallucis longus power was 3/5. Left Babinski sign was extensor. In the second case, a 42-year-old male, presented with a complaint of numbness over the left foot for 5–6 months. On examination, the power of the left ankle was 3/5, left extensor hallucis longus was 3/5. Both patients had EC in conus medullaris, which was hyperintense on T1-weighted magnetic resonance imaging and underwent laminectomy with the evacuation of the cyst with electrocoagulation of cyst epithelial lining. White ECs are extremely rare in the conus medullaris. Electrocoagulation of the cyst wall is like walking on a tight rope. Liberal electrocoagulation can lead to the neurological deficit but decreases the chances of recurrence. On the other hand, conservative electrocoagulation can lead to recurrence but decreases the chance of a new deficit. Recurrence should also lead to suspicion of atypical changes in the cyst wall, which may require adjuvant treatment such as radiotherapy and chemotherapy.

A Case of Emerging Epidermoid Cyst After Excision of Benign Cystic Teratoma Located in the Conus Medullaris

“…Cruveilhier was the first to describe spinal ECs in 1829 and called them tumors perlées, meaning pearl tumors. [11] ECs arise from the pathologic displacement of epidermal cells into the spinal canal and are lined with stratified squamous epithelium similar to the epidermis of the skin. [12][13][14] Spinal ECs are rare and constitute less than 1% of spinal tumors.…”

“…[12][13][14] Spinal ECs are rare and constitute less than 1% of spinal tumors. [11,12] Spinal ECs may be congenital or acquired. Congenital ECs are reported to be most commonly located in the conus medullaris region and occur due to accidental inclusion of the ectoderm during the closure of the neural tube.…”

“…Congenital ECs are reported to be most commonly located in the conus medullaris region and occur due to accidental inclusion of the ectoderm during the closure of the neural tube. [11,12,14] In addition, congenital ECs are frequently associated with hemivertebra, dermal sinus, spina bifida, and syringomyelia. [11] Acquired ECs are frequently found at the L1 level.…”

“…[11,12,14] In addition, congenital ECs are frequently associated with hemivertebra, dermal sinus, spina bifida, and syringomyelia. [11] Acquired ECs are frequently found at the L1 level. They are caused mainly by spinal trauma or any invasive procedure such as lumbar puncture or spine surgery that causes accumulation of ectopic epidermal cells in the intradural space and leads to cyst formation.…”

Intramedullary Epidermoid Cyst of the Conus Medullaris: A Case Report and Literature Review

“… 11 Short-term administration of steroids (for 3 days) may also help reduce the signs and symptoms of chemical meningitis if cyst fluid enters the subarachnoid space. 11 Most authors credit Matson (cited from Rand and Rand2S) for emphasizing the importance of not attempting to complete the capsule resection when the cyst wall is tightly adhered to the neural tissue. In this case, attempts to remove the entire cyst wall are ineffective and can lead to rapid neurological complications.…”