Intracranial Epidermoid Cyst with Hemorrhage: MR Imaging Findings

A 28-year-old woman with posthemorrhagic epidermoid tumor.

A, Axial T1 noncontrast-weighted fast spin-echo MR image (1823.5 milliseconds/7.4 milliseconds /2/750 milliseconds [TR/TE/excitation/TI]) shows a well-defined hyperintense extra-axial mass in the prepontine area and right cerebellopontine angle. Homogeneous hyperintensity is noted in most parts of the lesion. There is a focal area of heterogeneous intensity in the anterolateral aspect with hypointensity at the middle (arrow) and a crescent hyperintense portion at the periphery (small arrows). There are 2 oval shapes with hyperintensity in the dependent part of the lesion (arrowheads).

B, Axial T2-weighted fast spin-echo MR image (3500 milliseconds/86 milliseconds/2 [TR/TE/excitations]) shows the hyperintense lesion has a CSF equivalent signal intensity along with focal areas of heterogeneous hypointensity and 2 areas of homogenous hypointense signal intensity (arrowheads).

C, Axial fluid-attenuated inversion recovery MR image (8402 milliseconds/135 milliseconds/0.5/2100 milliseconds [TR/TE/excitation/TI]) shows no signal intensity drop in the lesion, and a clear border between the mass and CSF space is seen because the water signal intensity has been suppressed.

D, Axial contrast-enhanced T1-weighted fast spin-echo MR imaging image (450 milliseconds/9 milliseconds/2 [TR/TE/excitation]) of the same level shows faint enhancement (arrows) of the anterior nodule (compare with panel A).

E, On coronal T1-weighted, fat-suppressed contrast-enhanced MR imaging image, the hyperintensity within the lesion is not suppressed. Hydrocephalus with bilateral temporal horn dilation is noted.

F, Photomicrograph of the lesion specimen. The cyst is lined by keratinizing squamous epithelium and filled with lamellated keratinous debris. (hematoxylin-eosin [[H&E] stain; original magnification ×100).

G, Photomicrograph of the lesion specimen. Hemorrhage (H) with surrounding granulation tissue (G) made up about 25% of the specimen volume. (H&E stain; original magnification ×100).

H, Photomicrograph of the lesion specimen. Mild vascularity, with capillary sized vessels, was seen in the granulation tissue. (H&E stain; original magnification ×200).