Diagnosis of Intracranial Epidermoid Rupture by MR Imaging

Abstract

Intracranial epidermoids are benign tumours arising from retained ectodermal implants. Spontaneous rupture is an important though rare complication of intracranial epidermoid. To our knowledge, MR findings in spontaneous epidermoid rupture have not been well described to date. We report the case of a 60-year-old man who presented with a two day history of headache, altered sensorium and left hemiplegia. A diagnosis of ruptured epidermoid was made based on MR imaging findings which were subsequently proven by histopathology.

Evolution of epidermoid cyst into dermoid cyst: Embryological explanation and radiological-pathological correlation

“…On the contrary, there is no 'active secretion' within the epidermoid cyst due to the absence of skin appendages explaining the low incidence of rupture in epidermoid cysts. 7 The pathological distinction of epidermoid and dermoid cysts is based only on the presence of skin appendages in the cyst wall. When an epidermal inclusion cyst has the majority of its wall lining as only stratified squamous epithelium, with only small 'microscopic' areas of skin appendages, it is still a pathological dermoid cyst.…”

“…On the contrary, there is no ‘active secretion’ within the epidermoid cyst due to the absence of skin appendages explaining the low incidence of rupture in epidermoid cysts. 7…”