case_images: PMC9699848_01
case_images: Preoperative magnetic resonance imaging (MRI) T1 + c - coronal (upper left) and axial (upper right) view - demonstrating hypointense T1 right cerebellopontine angle lesion, with a small enhanced area on the medial side of the lesion. Preoperative MRI T2 demonstrating hyperintensity on T2-weighted image with focal areas of hypointensities in the periphery (lower left), correlating with keratin. Restricted diffusion is seen on diffusion-weighted image (lower right).
case_images: SNI-13-500-g001.jpg
case_images: PMC9699848_01_SNI-13-500-g001.jpg
case_images: F1
case_images: A small enhancing region was present on the medial side of the lesion [Figure 1].
case_images: Demonstrating areas of a simple squamous epithelial cyst with mounds of layered keratin, typical of an epidermoid cyst (H&E stained, x50).
case_images: SNI-13-500-g002.jpg
case_images: PMC9699848_01_SNI-13-500-g002.jpg
case_images: F2
case_images: The first specimen demonstrated areas of simple squamous epithelial cyst with mounds of layered keratin, typical of EC [Figure 2].
case_images: Demonstrating areas of proliferating squamous epithelium with thick projections (upper; H&E stained, x50); and areas of MT demonstrating dyskeratotic cells, few mitotic figures (red circled), and necrosis (lower; H&E stained, x100).
case_images: SNI-13-500-g003.jpg
case_images: PMC9699848_01_SNI-13-500-g003.jpg
case_images: F3
case_images: The other specimen contained thickened, proliferating squamous epithelium creating finger-like projections, and containing dyskeratotic and acantholytic cells and foci of necrosis, compatible with SCC [Figure 3].
case_images: Magnetic resonance imaging (MRI) T1 + c - axial view - postoperative MRI 11 months following surgical resection demonstrating local massive recurrence (left); and MRI 2 months following radiation therapy (right) demonstrating a decrease in the size of the lesion.
case_images: SNI-13-500-g004.jpg
case_images: PMC9699848_01_SNI-13-500-g004.jpg
case_images: F4
case_images: Eleven months following surgical resection, a follow-up MRI showed a local massive recurrence of the enhancing lesion [Figure 4]. An MRI scan done 2 months after radiation therapy showed a decrease in the size of the recurring lesion [Figure 4].