Imaging Characteristics of CNS Neuroblastoma-FOXR2: A Retrospective and Multi-Institutional Description of 25 Cases

Abstract

BACKGROUND AND PURPOSE: The 5th edition of the World Health Organization Classification of CNS tumors defines the CNS neuroblastoma FOXR2 in the group of embryonal tumors. Published clinical outcomes tend to suggest a favorable outcome after resection, craniospinal irradiation, and chemotherapy. This multicenter study aimed to describe imaging features of CNS neuroblastoma-FOXR2, which have been poorly characterized thus far. MATERIALS AND METHODS:On the basis of a previously published cohort of tumors molecularly classified as CNS neuroblastoma-FOXR2, patients with available imaging data were identified. The imaging features on preoperative MR imaging and CT data were recorded by 8 experienced pediatric neuroradiologists in consensus review meetings.RESULTS: Twenty-five patients were evaluated (13 girls; median age, 4.5 years). The tumors were often large (mean, 115 [ SD, 83] mL), showed no (24%) or limited (60%) perilesional edema, demonstrated heterogeneous enhancement, were often calcified and/or hemorrhagic (52%), were always T2WI-hyperintense to GM, and commonly had cystic and/or necrotic components (96%). The mean ADC values were low (687.8 [SD 136.3] Â 10 À6 mm 2 /s). The tumors were always supratentorial. Metastases were infrequent (20%) and, when present, were of nodular appearance and leptomeningeal. CONCLUSIONS:In our cohort, CNS neuroblastoma FOXR2 tumors showed imaging features suggesting high-grade malignancy and, at the same time, showed characteristics of less aggressive behavior. There are important differential diagnoses, but the results of this study may assist in considering this diagnosis preoperatively.

Neuroimaging features of FOXR2‐activated CNS neuroblastoma: A case series and systematic review

“…Tietze et al. reported that supratentorial location, often large size, multilobulated tumor shape, little‐or‐no perifocal edema, presence of nonsolid components, 22 T2WI hyperintensity compared to the cortex, low ADC values, and susceptibility artifact on T2‐ or susceptibility‐weighted images were frequently found, and these imaging features were also verified in this systematic review. We also identified that on nonenhanced CT, solid components of CNS NB‐FOXR2 appeared hyperdense (4/5, 80%) or isodense (1/5, 20%) relative to the cortex with characteristic calcification along the inner rim (4/5, 80%).…”

“…We screened these results according to the PRISMA 2020 guideline and narrowed them down to potentially eligible studies by removing duplicates, and irrelevant studies by title and abstract screening. After excluding 33 studies based on the exclusion criteria, six studies with 31 patients with CNS NB‐FOXR2 satisfied the criteria for the systematic review 3,18–22 . Other than 25 case series by Tietze et al., 22 which focused on MR imaging features, these studies were case‐based reports 3,18–21 .…”

“…After excluding 33 studies based on the exclusion criteria, six studies with 31 patients with CNS NB-FOXR2 satisfied the criteria for the systematic review. 3,[18][19][20][21][22] Other than 25 case series by Tietze 22 which focused on MR imaging features, these studies were case-based reports. 3,[18][19][20][21] The study selection process is summarized in the flow diagram in Figure 1.…”

Newly Recognized CNS Tumors in the 2021 World Health Organization Classification: Imaging Overview with Histopathologic and Genetic Correlation

“…67 The median age is 4.5 years (range, 1.4-16 years) without a sex predilection. 69 In the largest described series, tumors were large and supratentorial with invariable involvement of the deep white matter and frequent invasion of the cortex (80%) as well as a ventricular ependymal surface (64%). 69 The frontal lobe was the most common location, though involvement of multiple regions was common.…”

“…69 In the largest described series, tumors were large and supratentorial with invariable involvement of the deep white matter and frequent invasion of the cortex (80%) as well as a ventricular ependymal surface (64%). 69 The frontal lobe was the most common location, though involvement of multiple regions was common. Typical tumors were multilobulated, solid, and cystic/necrotic, T2-hyperintense, enhancing, and diffusion-restricting ( Fig 10).…”