Choroid plexus carcinoma: case report and discussion

Abstract

A 5-year-old girl presented with a 10-day history of headaches, blurred vision and ataxia. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain showed a well-circumscribed, contrast-enhancing tumour within the fourth ventricle, measuring 3.5×3.5×5.8 cm, with associated obstructive hydrocephalus. She had a gross total resection of the tumour. Histologically, the tumour was mostly solid with glandular rosette-like structures, some with small central lumina, and small cysts lined by epithelial cells. There were focal papillae lined by columnar cells and fibrovascular cores. There was mild nuclear pleomorphism. Some cells had a rhabdoid-like appearance. There were up to 3 mitoses per 10 high power fields (HPF), and necrosis. The cells were positive for vimentin, cytokeratins (AE1/AE3 and 5d3) and EMA. Ki-67 was positive in up to 30–50% of cells. p53 was positive in 50% of cells. Choroid plexus tumours are rare, accounting for 0.3–0.6% of all brain tumours. The World Health Organization (WHO) 2007 classification divides them into papillomas (grade 1), atypical papillomas (grade 2) and carcinomas (grade 3). Carcinomas constitute 20–40% of choroid plexus tumours with 80% arising in children. The case highlights the importance of differential diagnoses including atypical teratoid/rhabdoid tumour, ependymoma, papillary meningioma and metastatic carcinoma. Treatment requires total surgical resection with adjuvant chemoradiotherapy being controversial.