PMC4944084_01
Magnetic resonance imaging scans/histopathological findings. (a) Postcontrast T1 (right) and T2 weighted (center) sequences demonstrate a cystic, avidly enhancing mass, while the fluid-attenuated inversion recovery (FLAIR) sequence (left) shows enlargement of the cornu occipitale sinister with surrounding white matter oedema, consistent with ventricular entrapment; this might as well explain the blurred vision due to affection of the geniculocalcarine tract. (b) Transition zone, in a spindle cell neoplastic population, from an Antony A pattern (left) to an Antony B area (right). H&E. (c) High magnification photomicrograph showing intratumoural hyalinised vessels. H&E. (d) Reticular fibers stain. A pericellular reticulin frame, trademark of neurilemmal phenotype, is noticeable. (e) Antony B field with a small population of neoplastic, plump, gemistocyte-like cells. H&E. ((f), (g)) High magnification photomicrographs of the cells shown in (e): voluminous cells with eccentric nuclei and senescent atypia are evident.
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fig1
Magnetic resonance imaging scans showed an intraventricular, irregularly nodular, space-occupying lesion emerging from the posterior horn of the left lateral ventricle (Figure 1(a)). A pattern) as well as loosely clustered, hypocellular areas in a myxoid background (Antoni B pattern) (Figure 1(b)). Although Verocay bodies were not conspicuous, some blood vessels had hyalinised walls (Figure 1(c)) while a reticulin lattice enveloped every single cell (Figure 1(d)). Senescent changes were also present, with isolated cells in the Antoni B areas displaying a round, voluminous, eosinophilic cytoplasm with a displaced atypical nucleus; some of them even resembled a gemistocytic morphophenotype (Figures 1(e)-1(g)).
Immunohistochemistry panel. (a) PS100. (b) Collagen IV. ((c), (d)) Glial fibrillary acidic protein (GFAP) in an Antony A area (c) and in Antony B gemistocyte-like cells (d).
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The immunohistochemistry panel confirmed the diagnosis of neurilemmoma: PS100(+), collagen IV(+), and vimentin(+) (Figures 2(a) and 2(b)), but also unveiled a diffuse labelling for glial fibrillary acidic protein (GFAP) in both Antony patterns (Figures 2(c) and 2(d)).