Rapid malignant progression of an intraparenchymal choroid plexus papillomas

Metastatic choroid plexus papilloma presenting as a sellar mass: A case report and literature review

Background

Choroid plexus papillomas (CPPs) are rare neoplasms arising from choroid plexus epithelium representing <1% of all intracranial tumors. Symptoms vary based on location and regional mass effect; however, hydrocephalus is common due to cerebrospinal fluid flow obstruction and/or overproduction. Distant site metastasis or de novo formation in extraventricular sites is rare.

Case Description

A 57-year-old female with a history of a 4th ventricular CPP status post resection in 2004 and 2018 with subsequent gamma knife therapy in 2019 presented with increased thirst and urination. Since her initial surgery, she has experienced significant gait imbalance, diplopia, dysphagia, and right-sided hemiparesis and hemisensory loss. Magnetic resonance imaging revealed a new 1.5 × 1.8 cm suprasellar lesion. She underwent a left supraorbital craniotomy for tumor resection, with pathology revealing metastatic World Health Organization grade II CPP.

Conclusion

Extraventricular manifestation of CPP is rare. De novo or metastatic involvement of the sella has seldom been reported. Treatment should target gross total surgical resection. Adjuvant chemotherapy and radiation may be useful in higher-grade lesions.

Choroid plexus tumors: A spectrum from benign to malignant

Choroid plexus tumors (CPT) are believed to originate from outgrowths of the choroid plexus. Despite their broad spectrum of symptoms, invasive nature, and prognosis, most CPTs typically exhibit similar presentations due to their relationship with the cerebral ventricles, as well as the mechanical obstruction and mass effect associated with their growth. In addition, these tumors mainly affect the pediatric population, further complicating the differentiation between benign and malignant subtypes. The World Health Organization classifies CPTs into three grades, namely, grades I, II, or III, based on their mitotic activity, which determine the benign or malignant nature of the tumors. CPTs classified by the World Health Organization (WHO) include choroid plexus papillomas (CPP), atypical CPPs (aCPP), and malignant choroid plexus carcinomas (CPC). Choroid plexus adenomas represent an additional category of benign CPTs not officially classified by the WHO. Despite the variations in histology, immunohistochemistry, imaging, treatment, and prognosis, CPTs cannot be reliably distinguished based solely on clinical presentation. Therefore, in this review, we aim to provide a comprehensive overview of each tumor subtype, along with the current management approach and emerging treatments.

Molecular insights into malignant progression of atypical choroid plexus papilloma

Choroid plexus tumors are rare pediatric neoplasms ranging from low-grade papillomas to overtly malignant carcinomas. They are commonly associated with Li–Fraumeni syndrome and germline TP53 mutations. Choroid plexus carcinomas associated with Li–Fraumeni syndrome are less responsive to chemotherapy, and there is a need to avoid radiation therapy leading to poorer outcomes and survival. Malignant progression from choroid plexus papillomas to carcinomas is exceedingly rare with only a handful of cases reported, and the molecular mechanisms of this progression remain elusive. We report a case of malignant transformation of choroid plexus papilloma to carcinoma in a 7-yr-old male with a germline TP53 mutation in which we present an analysis of molecular changes that might have led to the progression based on the next-generation genetic sequencing of both the original choroid plexus papilloma and the subsequent choroid plexus carcinoma. Chromosomal aneuploidy was significant in both lesions with mostly gains present in the papilloma and additional significant losses in the carcinoma. The chromosomal loss that occurred, in particular loss of Chromosome 13, resulted in the losses of two critical tumor suppressor genes, RB1 and BRCA2, which might play a possible role in the observed malignant transformation.