Epidermoid, Intracranial

H&P

• HPI:
  • Presented to neurosurgery clinic
  • Chronic headache x5 years
  • Domestic violence with head injury
  • CT head completed in the ED
  • Obtained MRI afterwards
• PE: grossly normal
• Workup: CT head and brain MRI with and without contrast

Imaging

CT Head without Contrast

There is a large interhemispheric cystic lesion without calcification, more to the right.

Brain MRI without Contrast - DWI/ADC/FLAIR/GRE

Brain MRI - DWI

This tumor presents restricted diffusion on DWI sequences.

Brain MRI - Axial T2WI

The T2 signal does not follow CSF signal.

Brain MRI - Coronal T2WI

Brain MRI - T1WI, T2WI, T1WI w/ Contrast, T1WI w/ Contrast

There is no contrast enhancement of the tumor.

CTA Head - Thick Coronal

Bilateral ACAs are displaced laterally due to the mass effect of the tumor.

Differential Diagnosis

• Epidermoid cyst
• Dermoid cyst
• Craniopharyngioma
• Neurenteric cyst
• Arachnoid cyst

Surgical Intervention

• BrainLab intraoperative navigation
• Supine
• Head neutral in Mayfield holder
• Elevated for about 15°
• Bicoronal incision
• Bifrontal craniotomy, more to the right
• U-shape dural incision, based along the superior sagittal sinus
• Interhemispheric dissection between the falx and the right frontal lobe
• Separation of the tumor capsule from surrounding tissues
• Debulking of the tumor with CUSA (mainly fatty tissues)
• Left some capsule stuck to the normal brain
• Copious irrigation
• Hemostasis
• Dural closure
• Bone flap
• Scalp closure

Post-Op Course

• ICU for hourly neuro-checks overnight
• No new neurological deficits
• Transferred to regular floor on POD1
• Discharged home on POD2
• Pathology
  • Epidermoid cyst
  • CD68: Focally positive
  • GFAP: Focally positive

Post-Op MRI

Brain MRI - Axial DWI

There was a near total resection with some cavity border ischemic changes.

Discussion