Type:
Educational Exhibit
Keywords:
Neoplasia, Education and training, Cysts, Imaging sequences, Education, Diagnostic procedure, MR-Diffusion/Perfusion, MR, CT, Oncology, Neuroradiology spine, Neuroradiology brain
Authors:
A. Barakat, R. Pullicino, S. J. Mills; Liverpool/UK
DOI:
10.1594/ecr2018/C-0653
Conclusion
Although epidermoids represent less than 2% of primary intracranial tumours,
they are the commonest congenital intracranial tumour and the third commonest CPA lesion following vestibular Schwannoma and meningioma.
They account for up to 2% of spinal cord lesions,
increasing to 10% in patients below the age of 15.
Recurrence after resection can occur,
as can malignant degeneration,
albeit rare,
which tends to occur in recurrent tumours.
Therefore,
it is important that the radiologist has a high index of suspicion in order to recognise these lesions and distinguish them from other differentials.
Imaging pearl: Epidermoid cysts are best imaged using MRI.
They are usually of CSF-density with reduced signal on FLAIR (although the lesion may not completely null) and restriction of diffusion (high signal on DWI,
low or intermediate signal on ADC).
Differential diagnoses: arachnoid cyst,
meningioma,
dermoid cyst,
infected cyst/abscess and cystic/necrotic neoplasms.