Atypical choroid plexus papilloma
Citation, DOI, disclosures and article data
At the time the article was created Frank Gaillard had no recorded disclosures.
View Frank Gaillard's current disclosuresAt the time the article was last revised Yaïr Glick had no financial relationships to ineligible companies to disclose.
View Yaïr Glick's current disclosuresAtypical choroid plexus papillomas are WHO grade 2 tumours derived from choroid plexus epithelium with intermediate clinical and pathological features between more indolent choroid plexus papillomas and more aggressive choroid plexus carcinomas.
As clinically, and on imaging, they are difficult to distinguish from choroid plexus papillomas and therefore their description is not repeated here.
Pathology
Atypical choroid plexus papillomas are considered WHO grade 2 tumours in the current (2021) WHO classification of CNS tumours 2. They are distinguished from choroid plexus papillomas primarily on the basis of increased mitotic activity (≥2 mitoses per 10 high-power fields; choroid plexus carcinomas have ≥5 mitoses per 10 high-power fields) 1.
Other features that may be present include 1:
- increased cellularity
- nuclear pleomorphism
- more solid growth pattern with blurring of papillary pattern
- necrosis
Quiz questions
References
- 1. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK "WHO Classification of Tumours of the Central Nervous System. 4th Edition Revised" ISBN: 9789283244929
- 2. Louis D, Perry A, Wesseling P et al. The 2021 WHO Classification of Tumors of the Central Nervous System: A Summary. Neuro-Oncology. 2021;23(8):1231-51. doi:10.1093/neuonc/noab106 - Pubmed
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