Atypical CT and MRI aspects of an epidermoid cyst

Unusual CT and MRI? Appearance** of an Epidermoid Cyst: A Case Report

“…They were first described by Lepreste in 1828 [2]. Acquired epidermoid cysts caused by head trauma or lumbar puncture are rare and usually present as extradural masses [2].…”

“…Epidermoid cysts have a thin capsule of stratified, keratinized squamous epithelium [2]. They are usually filled with white waxy material rich in cholesterol crystals mixed with cellular debris, which is the result of progressive desquamation and breakdown of keratin from the epithelial lining [2].…”

“…They are usually filled with white waxy material rich in cholesterol crystals mixed with cellular debris, which is the result of progressive desquamation and breakdown of keratin from the epithelial lining [2]. Their slow linear growth accounts for the late age of presentation [2].…”

“…On long TR/TE sequences, these tumors show hyperintensity, similar to or greater than that of CSF [5]. On FLAIR sequences, the signal is heterogeneous, hyperintense to CSF [2]. Epidermoid cysts appear strongly hyperintense on diffusion-weighted images [2].…”

“…A few cases of hyperdense epidermoid cysts have been reported [2]. On MRI, these lesions appear hyperintense on T1-weighted images and hypointense on T2-weighted images [2].…”