PT  - JOURNAL ARTICLE
AU  - Wagner, M.W.
AU  - Nobre, L.
AU  - Namdar, K.
AU  - Khalvati, F.
AU  - Tabori, U.
AU  - Hawkins, C.
AU  - Ertl-Wagner, B.B.
TI  - T2-FLAIR Mismatch Sign in Pediatric Low-Grade Glioma
AID  - 10.3174/ajnr.A7916
DP  - 2023 Jul 01
TA  - American Journal of Neuroradiology
PG  - 841--845
VI  - 44
IP  - 7
4099  - http://www.ajnr.org/content/44/7/841.short
4100  - http://www.ajnr.org/content/44/7/841.full
SO  - Am. J. Neuroradiol.2023 Jul 01; 44
AB  - BACKGROUND AND PURPOSE: No qualitative imaging feature currently predicts molecular alterations of pediatric low-grade gliomas with high sensitivity or specificity. The T2-FLAIR mismatch sign predicts IDH-mutated 1p19q noncodeleted adult gliomas with high specificity. We aimed to assess the significance of the T2-FLAIR mismatch sign in pediatric low-grade gliomas.MATERIALS AND METHODS: Pretreatment MR images acquired between January 2001 and August 2018 in pediatric patients with pediatric low-grade gliomas were retrospectively identified. Inclusion criteria were the following: 1) 0–18 years of age, 2) availability of molecular information in histopathologically confirmed cases, and 3) availability of preoperative brain MR imaging with non-motion-degraded T2-weighted and FLAIR sequences. Spinal cord tumors were excluded.RESULTS: Three hundred forty-nine patients were included (187 boys; mean age, 8.7 [SD, 4.8] years; range, 0.5–17.7 years). KIAA1549–B-Raf proto-oncogene (BRAF) fusion and BRAF p.V600E mutation were the most common molecular markers (n = 148, 42%, and n = 73, 20.7%, respectively). The T2-FLAIR mismatch sign was present in 25 patients (7.2%). Of these, 9 were dysembryoplastic neuroepithelial tumors; 8, low-grade astrocytomas; 5, diffuse astrocytomas; 1, a pilocytic astrocytoma; 1, a glioneuronal tumor; and 1, an angiocentric glioma. None of the 25 T2-FLAIR mismatch pediatric low-grade gliomas were BRAF p.V600E–mutated. Fourteen of 25 pediatric low-grade gliomas with the T2-FLAIR mismatch sign had rare molecular alterations, while the molecular subtype was unknown for 11 tumors.CONCLUSIONS: The T2-FLAIR mismatch sign was not observed in the common molecular alterations, BRAF p.V600E–mutated and KIAA1549-BRAF fused pediatric low-grade gliomas, while it was encountered in pediatric low-grade gliomas with rare pediatric molecular alterations.DNETdysembryoplastic neuroepithelial tumorpLGGpediatric low-grade gliomaRAS/MAPKRAS-mitogen-activated protein kinaseTKDDtyrosine kinase domain duplication