Hyperdense intracranial epidermoid cysts: a study of 15 cases

Abstract

Recurrent leakage of the irritating cyst contents and subsequent chemical inflammatory response may be responsible for the high-density on CT scans and the cystic nature. A correct histological diagnosis is important because, in contrast to typical ECs and other lesions, HIECs are more prone to spread intra-operatively and result in severe aseptic meningitis.

Epidermoid Cyst in Meckel's Cave With Unusual Computed Tomography and Magnetic Resonance Imaging Findings -Case Report-

“…13) Epidermoid cysts typically appear as homogeneous hypodensity on CT. 11) Occasionally, epidermoid cysts with unusual CT and MR imaging appearances have been described. 2,6,11,12,15) The typically hypodense epidermoids have a pearly appearance with white, waxy material rich in cholesterol crystals, whereas the atypically hyperdense epidermoids are grossly cystic and contain viscid fluid of various colors. 11) The atypical aspects such as hyperdensity on CT and hyperintensity signal on T 1 -weighted imaging may be attributed to high protein concentrations and high viscosity.…”

“…11) The atypical aspects such as hyperdensity on CT and hyperintensity signal on T 1 -weighted imaging may be attributed to high protein concentrations and high viscosity. 2,6,11,12,15) Although the hyperintense signal of epidermoid cysts on diffusion-weighted imaging is useful for differentiation from arachnoid cysts and related to the T 2 shine-through effect, 4) atypical epidermoid cysts with viscous components show hypointensity on T 2 -weighted and diffusion-weighted imaging. 2,6) In our present case, the lesion in the middle cranial fossa was found during surgery to be a classical pearly epidermoid cyst, whereas the adjacent lesion in the posterior cranial fossa was a cystic epidermoid cyst with viscous fluid.…”

“…10) Epidermoid cysts generally appear as well-defined lobulated hypodense masses on computed tomography (CT), and as hypointense on T 1 -weighted magnetic resonance (MR) imaging and hyperintense on T 2 -weighted MR imaging. 14) Occasionally, epidermoid cysts present with unusual appearances such as hyperdense on CT, 6,11) hyperintense on T 1 -weighted and hypointense on T 2 -weighted MR imaging. 2,12,15) Here, we describe a case of an epidermoid cyst in Meckel's cave with unusual CT and MR imaging findings.…”

Recurrent Epidermoid Cyst With Malignant Transformation Into Squamous Cell Carcinoma -Case Report-

“…6) In our case, the initial epidermoid cyst had these CT features, whereas the recurrent epidermoid cyst appeared as hyperdense. Epidermoid cysts appearing as CT hyperdense are rare, 9) and the reason for this appearance is unknown. Protein content, saponification of keratinized debris to calcium soaps, and abundance of polymorphonuclear leukocytes have been proposed.…”

Prolactin-Producing Pituitary Adenoma With Abundant Spherical Amyloid Deposition Masquerading as Extensive Calcification -Case Report-

“…16,21) Spherical amyloid in pituitary adenoma contained an abundance of 4-kDa peptides. However, two previous reports on CT findings of amyloid deposited in pituitary adenoma showed decreased attenuation of the tumor.…”