EC Paediatrics

Choroid plexus carcinoma is a rare, aggressive intraventricular neoplasm that predominantly affects young children. A 5-year- old girl presented with a syndrome of raised intracranial pressure. Computed tomography demonstrated a large lobulated hyperattenuating mass centered in the right lateral ventricle, associated with marked asymmetric obstructive hydrocephalus and mass effect. After contrast administration, the tumor enhanced intensely and heterogeneously. Magnetic resonance imaging showed an irregular heterogeneous intraventricular mass with internal non-enhancing areas, extensive peritumoral edema, heterogeneous low apparent diffusion coefficient foci, and avid heterogeneous gadolinium enhancement. These findings favored a malignant choroid plexus tumor. The patient underwent subtotal resection. Initial histologic assessment favored atypical choroid plexus papilloma; however, neuropathologic reassessment integrating morphology and immunohistochemistry established choroid plexus carcinoma, central nervous system World Health Organization grade 3. Tumor cells showed diffuse cytokeratin expression, S100 and vimentin positivity, negative p53 staining, and a Ki-67 proliferation index of approximately 60%. This case highlights imaging features that should raise suspicion for carcinoma rather than a lower-grade choroid plexus tumor and illustrates the value of integrated radiologic- pathologic assessment when the initial diagnosis is equivocal.

Keywords: Choroid Plexus Carcinoma; Pediatric Brain Tumor; Intraventricular Tumor; Hydrocephalus; Magnetic Resonance Imaging