title: Atypical intracranial epidermoid cysts: rare anomalies with unique radiological features.
abstract: Epidermoid cysts are benign slow growing extra-axial tumours that insinuate between brain structures, while their occurrences in intra-axial or intradiploic locations are exceptionally rare. We present the clinical, imaging, and pathological findings in two patients with atypical epidermoid cysts. CT and MRI findings for the first case revealed an intraparenchymal epidermoid cyst that demonstrated no restricted diffusion. The second case demonstrated an aggressive epidermoid cyst that invaded into the intradiploic spaces, transverse sinus, and the calvarium. The timing of ectodermal tissue sequestration during fetal development may account for the occurrence of atypical epidermoid cysts.
authors: Department of Imaging & Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Eric K C
authors: EK
authors: Law
authors: Department of Imaging & Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Ryan K L
authors: RK
authors: Lee
authors: Department of Imaging & Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Alex W H
authors: AW
authors: Ng
authors: Department of Imaging & Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong ; Department of Radiology, Kwong Wah Hospital, Kowloon, Hong Kong.
authors: Deyond Y W
authors: DY
authors: Siu
authors: Department of Anatomical & Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Ho-Keung
authors: HK
authors: Ng