PMC4602954_01
MRI of the brain revealed a heterogeneous contrast-enhancing mass in the left internal auditory canal (A) in Dec 2008. One year later, the mass had increased in size (B). In July 2011, the mass had further increased in size, and had evolved into the left CPA with heterogeneous enhancement (C). CPA = cerebellopontine angle, MRI = magnetic resonance imaging.
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F1
A magnetic resonance imaging (MRI) scan of the brain revealed a heterogeneous contrast-enhancing mass that measured 0.5 x 0.3 x 0.3 cm in the left internal auditory canal, which resulted in the diagnosis of an acoustic neuroma (Figure 1A). A computed tomography (CT) scan indicated the presence of a mass that measured 0.5 x 0.5 x 0.4 cm in the left internal auditory canal (Figure 1B). The scan also revealed a heterogeneous enhancing signal and cyst formation in the mass (Figure 1C).
The tumor was completely removed in July 2011. The majority of the tumor cells was of the rhabdoid phenotype and displayed a vesicular nucleus, prominent nucleolus, and an eosinophilic cytoplasm (A). Immunostaining showed a lack of INI1 protein expression in the tumor cells (B), and FISH showed a deletion of the INI1 gene (C). FISH = fluorescence in situ hybridization.
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F2
The majority of the tumor cells demonstrated a rhabdoid phenotype, characterized by an eccentrically placed vesicular nucleus, a prominent nucleolus, and an eosinophilic inclusion-like cytoplasm (Figure 2A). Immunostaining revealed a lack of integrase interactor 1 (INI1) protein expression in the tumor cells, and fluorescence in situ hybridization (FISH) revealed a hemizygous deletion of the INI1 gene region on 22q11.2 (Figure 2B and C).
In June 2012, MRI revealed a well-demarcated intraspinal mass at the C6-T7 level with homogeneous contrast enhancement (A and B). Microscopically, the tumor was primarily composed of characteristic rhabdoid cells (C) and lacked INI1 immunoreactivity (D). MRI = magnetic resonance imaging.
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F3
T1-weighted images, slightly hyperintense on T2-weighted images, and homogeneously contrast enhancing (Figure 3A and B). The tumor was completely removed and subjected to a pathological examination. Microscopically, the tumor contained characteristic rhabdoid cells with areas that resembled a classical PNET (Figure 3C). Immunostaining showed that the tumor cells had decreased INI1 protein expression (Figure 3D), similar to that of the left cerebellopontine mass, which was described a year earlier.