Introduction

Choroid Plexus Tumours (CPTs) account for 1–4% of all brain tumours in children. Atypical choroid plexus papillomas (aCPPs) are a subset of these tumours, defined over a decade ago, yet no consensus exists on the optimal approach to their management.

Methods

We conducted a retrospective analysis of all patients treated for CPTs at the Hospital for Sick Children between January 1, 2000, and December 31, 2018, and focused on patients with aCPP. Data extracted from the patient records for analysis included: demographic and clinical features, radiological imaging, surgical and adjuvant therapies, key pathological features, immunohistochemical staining for TP53 and tumour karyotype. Six of seven aCPP samples were profiled using Illumina HumanMethylationEPIC arrays and the top 10,000 most variably methylated probes were visualized using tSNE. Copy number inferencing was also performed.

Results

Twenty-nine patients were diagnosed with CPT, seven of whom had a diagnosis of aCPP as confirmed by histological review. Methylation profiling demonstrated that aCPPs clustered with both choroid plexus papillomas (CPPs) and choroid plexus carcinomas (CPCs). Complete resection of the tumour was pursued in all cases of aCPP and no patient received adjuvant therapy. All aCPP patients were alive at last follow up.

Conclusions

This limited case series suggests that paediatric aCPP can be successfully managed with surgical resection alone, followed by a ‘watch and wait’ approach thus avoiding adjuvant therapies. A deeper understanding of the biology of aCPP is required to identify objective markers which can help provide robust risk stratification and inform treatment strategies.

中文翻译：

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小儿非典型脉络丛乳头状瘤：是否需要辅助治疗？

介绍

脉络丛肿瘤 (CPTs) 占儿童所有脑肿瘤的 1-4%。非典型脉络丛乳头状瘤 (aCPPs) 是这些肿瘤的一个子集，十多年前就已定义，但对其最佳治疗方法尚无共识。

方法

我们对 2000 年 1 月 1 日至 2018 年 12 月 31 日期间在病童医院接受 CPT 治疗的所有患者进行了回顾性分析，重点关注 aCPP 患者。从患者记录中提取用于分析的数据包括：人口统计学和临床​​特征、放射成像、手术和辅助治疗、关键病理特征、TP53 的免疫组织化学染色和肿瘤核型。使用 Illumina HumanMethylationEPIC 阵列分析了七个 aCPP 样本中的六个，并使用 tSNE 可视化了前 10,000 个甲基化最多的探针。还进行了拷贝数推断。

结果

29 名患者被诊断为 CPT，其中 7 名经组织学检查确诊为 aCPP。甲基化分析表明，aCPPs 与脉络丛乳头状瘤 (CPPs) 和脉络丛癌 (CPCs) 都聚集在一起。在所有 aCPP 病例中都进行了肿瘤的完全切除，并且没有患者接受辅助治疗。所有aCPP患者在最后一次随访时均存活。

结论

这个有限的病例系列表明，仅通过手术切除即可成功管理儿科 aCPP，然后采用“观察和等待”方法，从而避免辅助治疗。需要对 aCPP 的生物学有更深入的了解，以确定客观标志物，这些标志物可以帮助提供可靠的风险分层并为治疗策略提供信息。