case_images: PMC8721377_01
case_images: (a) Axial CT of the head with no lateral semicircular canal present. (b) Axial CT of the head showing a hypoplastic cochlea. (c) Axial T1-weighted MRI of the head without gadolinium revealing a mastoid lesion with bright signal. (d) Axial T2-weighted MRI of the head with bright signals from both components of a mastoid lesion.
case_images: 10.1177_2050313X211067913-fig1.jpg
case_images: PMC8721377_01_10.1177_2050313X211067913-fig1.jpg
case_images: fig1-2050313X211067913
case_images: There was no lateral semicircular canal (Figure 1(a)) and the cochlea appeared hypoplastic (Figure 1(b)). The cystic structure was non-enhancing on T1 with gadolinium and bright on T1 without gadolinium (Figure 1(c)) and T2 (Figure 1(d)), suggesting internal fluid with protein content.
case_images: (a) Pre-excision view of the mastoid cystic mass. (b) Post-excision view of the remaining bony shell and underlying facial nerve after complete resection of the mastoid cystic mass.
case_images: 10.1177_2050313X211067913-fig2.jpg
case_images: PMC8721377_01_10.1177_2050313X211067913-fig2.jpg
case_images: fig2-2050313X211067913
case_images: On gross inspection, the tumor was red-brown in color with multicystic compartments filled with gelatinous fluid (Figure 2a). Distinct thick bony shell, possibly due to long-term bony remodeling, was noted peripherally (Figure 2b).
case_images: Low-powered (x40) view of simple columnar epithelium with goblet cells and two submucosal muscular layers (trichrome stain).
case_images: 10.1177_2050313X211067913-fig3.jpg
case_images: PMC8721377_01_10.1177_2050313X211067913-fig3.jpg
case_images: fig3-2050313X211067913
case_images: A trichrome stain highlighted fibrosis and muscular tissue, and desmin immunoreactive smooth muscles were seen in two distinct submucosal layers, resembling the muscularis mucosa and muscularis propria (Figure 3).