Intra-Fourth-Ventricular Choroid Plexus Papilloma Miming Ependymoma 99

Intra-fourth-ventricular choroid plexus papilloma miming ependymoma 99

Case report Clin Ter 2021; 172 (2):99-103 doi: 10.7417/CT.2021.2292

Intra-fourth-ventricular choroid plexus papilloma miming ependymoma Tran Anh Tuan1,2, Phung Anh Tuan3, Nguyen Minh Duc2,4,5*

1Department of Radiology, Bach Mai Hospital, Ha Noi, Vietnam; 2Department of Radiology, Hanoi Medical University, Ha Noi, Vietnam; 3Department of Radiology, Vietnam Millitary Medical University, Hanoi, Vietnam 4Department of Radiology, Pham Ngoc Thach University of Medicine, Ho Chi Minh city, Vietnam; 5Department of Radiology, Children’s Hospital, Ho Chi Minh City, Vie- tnam

Abstract chymally. Ependymomas account for fewer than 5% of all neuroepithelial tumors, 10% of all pediatric brain tumors, Choroid plexus papilloma (CPP), a low incidence central nervous and fewer than 40% of brain tumors that develop in children system (CNS) tumor, typically develops as an intraventricular neo- under the age of 3 (5,6). plasm arising from the epithelium of the choroid plexus. Infratentorial Thus, CPP and ependymoma represent two of the most CPP is predominantly clustered in adults with roughly 70% in the common intraventricular neoplasms. However, to the best of fourth ventricle, while supratentorial CPP commonly found in the our knowledge, the overlap between these two tumor types lateral ventricles, is the most frequent location in children. The clini- has not been explored in existing reports. In this article, we cal and imaging features of CPP are not typical and may induce the described an atypical presentation of fourth-ventricular CPP misdiagnosis as other types of primary brain tumors. In this paper, that resembled an ependymoma. we described a fourth-ventricular CPP that was misdiagnosed as ependymoma despite the manipulation of groundbreaking magnetic resonance imaging (MRI) sequences. These findings indicated that Case presentation CPP should be considered when performing the differential diagnosis of intraventricular neoplasms. Clin Ter 2021; 172 (2):99-103. doi: A 1-year-old female, suffering from nausea and vomi- 10.7417/CT.2021.2292 ting, was sent to the Department of Neurosurgery, Children’s Hospital 2. Her medical profile was not specific, and no Key words: choroid plexus papilloma, ependymoma, fourth ventricle neurological deficits were identified during routine clinical tumor, children assessment. All laboratory test results and tumor marker evaluations were within the normal limits. She underwent a brain magnetic resonance imaging (MRI) scan, with contrast agent. Data from the MRI scan showed the appearance of hydrocephalus, but no supratentorial lesions. On T2-weighted imaging, a solid tumor (48 mm × 30 mm Introduction × 35 mm) was observed in the fourth ventricle, without surrounding cerebellar edema (Fig. 1). The tumor extended Choroid plexus papilloma (CPP) generally presents as an through the left Luschka foramen. Hemosiderin and calci- intraventricular neoplasm that originates from the choroid fication elements were not observed inside the lesion. The plexus epithelium and accounts for fewer than 4% of all mean apparent diffusion coefficient (ADC) values for the intracranial neoplasms in children and fewer than 0.5% of parenchyma and tumor were 0.74 and 0.86 × 10-3 mm2/s, neoplasms in adults (1). CPP is localized infratentorially respectively (Fig. 2). The relative enhancement (%), peak in adults, with approximately 70% positioned in the fourth enhancement, peak relative enhancement (%), time to peak ventricle, whereas, in children, the most common site is (s), wash-in rate (s-1), wash-out rate (s-1), and area under the supratentorial, located in the lateral ventricles (2). Althou- curve values of the parenchyma compared with the tumor, gh CPP may occur at any age, 70% of all cases have been as derived from the axial T1-perfusion map, were 0.55 vs identified in patients under the age of 2 (1-4). 46.78, 76.70 vs 813.29, 4.67 vs 52.05, 44.49 vs 69.21, 5.79 Ependymoma refers to a glial cell tumor that com- vs 96.71, 19.54 vs 6.83, and 876.51 vs 88,033.31, respecti- monly develops in cells that line the ventricular system or vely (Fig. 3). The preliminary diagnosis, based on available the central canal, and less often, ependymomas are located clinical and imaging data, supported ependymoma. Gross- outside of the central nervous system (CNS), or intraparen- total tumor resection was indicated, and the histopathological

Correspondence: * Nguyen Minh Duc, MD, Department of Radiology, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam. E-mail: [email protected], ORCID: 0000-0001-5411-1492

Fig. 1. A hyperintense solid tumor, located in the fourth ventricle and extending through left Luschka foramen, on axial T2-weighted imaging

Fig. 2. Axial apparent diffusion coefficient of the tumor and the parenchyma. Intra-fourth-ventricular choroid plexus papilloma miming ependymoma 101

Fig. 3. The detailed perfusion parameters for the tumor (blue ROI) and the parenchyma (orange ROI).

Fig. 4. Histopathological results show that the tumor was composed of papillae, lined by cuboidal to columnar choroid plexus epithelium, with a central fibrovascular core. Nuclear pleomorphism was not observed (H & E, × 40). 102 Tran Anh Tuan, et al. evaluation of the excised tumor tissues was consistent with misdiagnosed as ependymoma, a more common, fourth-ven- typical CPP (Fig. 4). The patient was discharged 12 days tricular brain tumor found in pediatric patients. Therefore, following surgery, without any adverse events. the imaging characteristics that can be used to differentiate between the CPP and other brain tumors are not specific enough to separate these two tumor types effectively. The treatment of choice for both CPP and ependymo- Discussion ma is gross surgical tumor excision. However, for cases in which the tumor extends into the Luschka and Magendie Choroid plexus tumors are categorized as CPP (grade foramina or cerebellopontine angle, surgical procedures can I), atypical CPP (grade II), and choroid plexus carcinoma be complicated, the complete eradication of tumor tissue (grade III), according to the 2016 World Health Organi- might not be possible without disrupting adjacent eloquent zation (WHO) classification guidelines (7). Microscopic structures (12-14). examination reveals that CPP features papillary fronds, lined by bland columnar epithelium. Generally, CPP does not feature mitotic activity, nuclear pleomorphism, or necrosis Conclusion (4). Ependymomas are classified as subependymoma and myxopapillary ependymoma (grade I), classic ependymoma This report described an atypical CPP, which resulted (grade II), and anaplastic ependymoma (grade III), according in the misdiagnosis of ependymoma, despite the employ- to the 2016 World Health Organization (WHO) classification ment of advanced MRI protocols. Further studies remain guidelines (7). Among these types, classic ependymoma is vital to identify imaging features capable of discriminating the most common. CPP from other brain neoplasms, which will improve the Unlike most other primary brain neoplasms, which are precision and effectiveness of diagnostic and prognostic more common in the infratentorial region in children and the outcomes. supratentorial compartment in adults, this trend is inverted for CPPs, with 70% of CPPs in adults situated in the fourth Ethical statement ventricle, whereas in children, CPPs are usually located in the lateral ventricles (2). Hence, pediatric CPP in the fourth Institutional review board of Children’s hospital 2 appro- ventricle, as observed in our case, is quite uncommon. Due ved this prospective study (Ref: 352/NĐ2-CĐT). Informed to ventricular system obstruction, CPPs almost always consent of legal guardians of patient was obtained. cause hydrocephalus, inducing symptoms that include he- Acknowledgment adache, nausea, and vomiting. On imaging, CPP typically We would like to express our gratitude to Dr Mai Tan appears as a well-circumscribed, lobulated mass, which is Lien Bang, Dr Dang Do Thanh Can, Dr Huynh Quang Huy, hyperintense compared to the adjacent normal-appearing Mrs Dang Thi Bich Ngoc, and Mr Nguyen Chanh Thi for parenchyma. CPPS generally enhance homogeneously and their assistance and technical support in completing this vividly, exhibiting an irregular, frond-like pattern, resulting research. in a cauliflower-like appearance. The presence of strikingly ICMJE Statement and Conflict of interest heterogeneous contrast enhancement or a markedly necrotic The authors have no conflict of interest to disclose. appearance indicates choroid plexus carcinoma (4). Speckled Funding sources ossification is observed inside of the tumor in approximately No financial support was received for this case report. 25% of CPPs (4). In our case, the cauliflower-like appearance Author’s contribution on the T1-perfusion map was not typical (8-11). TAT and PAT contributed equally to this article there- The three most well-known and common posterior cra- fore considered as co-first authors. NMD and TAT gave a nial fossa tumors in children are medulloblastoma, pilocytic substantial contribution in acquisition, analysis, and data astrocytoma, and ependymoma (12,13). Approximately 60% interpretation. 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