case_images: PMC11102693_01
case_images: Brain magnetic resonance imaging including axial FLAIR (a), Diffusion Weighted sequences (DWI) (b) with apparent diffusion coefficient (ADC) map (c), sagittal T1-weighted-sequences with gadolinium injection (d) and axial with MIP reconstructed image (e) reveals a large well-defined, lobulated right lateral intraventricular tumor with heterogeneous structure, mainly due to the presence of cysts (arrowhead). The mass appears slightly hyperintense on DWI (arrows) with a similar appearance to brain parenchyma on ADC map. Upon gadolinium injection, a slight enhancement is observed, and curvilinear structures within the tumor revealed to be vessels at MIP reconstruction (e, arrows).
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case_images: Intensity Projection (MIP) reconstructed images (Figure 1). Initially, an aCPP was suspected based on clinical details and atypical imaging features.
case_images: Anatomopathological examination reveals a papillomatous proliferation consisting of papillae of variable size (Image on the left). Papillae are lined with tall columnar cells showing slight cytonuclear atypia (Image on the right).
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case_images: Histopathological examination, when performed, confirmed the diagnosis of an aCPP (Figure 2).
case_images: Histological examination shows positivity for cytokeratin AE1/AE3 (a). The mitotic activity, estimated with a Ki67 index, is at 15% (b).
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case_images: The tumor consisted of a proliferation of papillae of variable size, exhibiting cytonuclear atypia with positivity for cytokeratin AE1 and AE3, associated with a Ki 67 index of 15% (Figure 3).