Choroid plexus papilloma is a benign (G1), typically childhood-onset, intraventricular tumor.
It is globular (or cauliflower-like) macroscopically and well-demarcated and usually arises from the lateral ventricle (patients < 20 yo) or fourth ventricle (any age).
Histopathologically they demonstrate epithelial cells lining delicate fibrovascular cores in a papillary (nipple-shaped) pattern.
Typically demonstrate heterogenous signal intensity and contrast enhancement on MRI.
Can easily be mistaken for choroid plexus hypertrophy.
Choroid plexus papilloma has a good prognosis whereas choroid plexus carcinoma has a poor prognosis.
Choroid plexus carcinoma (which typically occurs in young children) demonstrates malignant pathology with invasion of brain tissue and hemorrhage/necrosis and thus a poor prognosis.
Choroid plexus papilloma is ~ 5 times more common than choroid plexus carcinoma.
References
Adesina, Adekunle M., Tarik Tihan, Christine E. Fuller, and Tina Young Poussaint. Atlas of Pediatric Brain Tumors. Springer, 2016.
Gray, Frangoise, Charles Duyckaerts, and Umberto De Girolami. Escourolle and Poirier’s Manual of Basic Neuropathology. OUP USA, 2013.
Sethi, Divya, Rashmi Arora, Ketan Garg, and Parul Tanwar. “Choroid Plexus Papilloma.” Asian Journal of Neurosurgery 12, no. 1 (2017): 139–41. https://doi.org/10.4103/1793-5482.153501.
Tonn, Jörg-Christian, Manfred Westphal, and J. T. Rutka. Oncology of CNS Tumors. Springer Science & Business Media, 2010.
Yachnis, Anthony T., and Marie L. Rivera-Zengotita. Neuropathology E-Book: A Volume in the High Yield Pathology Series. Elsevier Health Sciences, 2012.
Nephron. English: Micrograph of a Choroid Plexus Papilloma. H&E Stain. [object HTMLTableCellElement]. Own work. https://commons.wikimedia.org/wiki/File:Choroid_plexus_papilloma_micrograph.jpg.
High-mag choroid plexus papilloma histopahtological slide (right-side of image, foreground)
MD, Martin Hasselblatt. Photomicrograph of Hematoxylin-Eosin Stained Section of a Choroid Plexus Papilloma (Grade I WHO)at 400x Magnification. Image Taken Using an Olympus Microscope and Analysis-Imaging Software on 10-24-2006 by Martin Hasselblatt MD. October 24, 2006. Own work. https://commons.wikimedia.org/wiki/File:Choroidplexuspapilloma_HE400x.png.