Imaging Characteristics of Pediatric Diffuse Midline Gliomas with Histone H3 K27M Mutation.
The 2016 World Health Organization Classification of Tumors of the Central Nervous System includes "diffuse midline glioma with histone H3 K27M mutation" as a new diagnostic entity. We describe the MR imaging characteristics of this new tumor entity in pediatric patients.



We retrospectively reviewed imaging features of pediatric patients with midline gliomas with or without the histone H3 K27 mutation. We evaluated the imaging features of these tumors on the basis of location, enhancement pattern, and necrosis.



Among 33 patients with diffuse midline gliomas, histone H3 K27M mutation was present in 24 patients (72.7%) and absent in 9 (27.3%). Of the tumors, 27.3% (n= 9) were located in the thalamus; 42.4% (n= 14), in the pons; 15% (n= 5), within the vermis/fourth ventricle; and 6% (n= 2), in the spinal cord. The radiographic features of diffuse midline gliomas with histone H3 K27M mutation were highly variable, ranging from expansile masses without enhancement or necrosis with large areas of surrounding infiltrative growth to peripherally enhancing masses with central necrosis with significant mass effect but little surrounding T2/FLAIR hyperintensity. When we compared diffuse midline gliomas on the basis of the presence or absence of histone H3 K27M mutation, there was no significant correlation between enhancement or border characteristics, infiltrative appearance, or presence of edema.



We describe, for the first time, the MR imaging features of pediatric diffuse midline gliomas with histone H3 K27M mutation. Similar to the heterogeneous histologic features among these tumors, they also have a diverse imaging appearance without distinguishing features from histone H3 wildtype diffuse gliomas.
From the Department of Radiology (M.S.A., E.F., M.C.M., J.E.V.-M., S.C.).
M S
0000-0002-4877-8271
MS
Aboian
Division of Neuropathology (D.A.S.), Department of Pathology.
D A
0000-0003-4571-7999
DA
Solomon
From the Department of Radiology (M.S.A., E.F., M.C.M., J.E.V.-M., S.C.).
E
0000-0002-6537-6960
E
Felton
From the Department of Radiology (M.S.A., E.F., M.C.M., J.E.V.-M., S.C.).
M C
0000-0002-4538-0823
MC
Mabray
From the Department of Radiology (M.S.A., E.F., M.C.M., J.E.V.-M., S.C.).
J E
0000-0002-5910-0757
JE
Villanueva-Meyer
Division of Pediatric Hematology/Oncology (S.M.), Department of Pediatrics.|Department of Neurological Surgery (S.M.).|Division of Child Neurology (S.M.), Department of Neurology, University of California, San Francisco, San Francisco, California.
S
0000-0002-3452-5150
S
Mueller
From the Department of Radiology (M.S.A., E.F., M.C.M., J.E.V.-M., S.C.) soonmee.cha@ucsf.edu.
S
0000-0002-5924-5876
S
Cha
D000293:Adolescent; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics; D016543:Central Nervous System Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000235:genetics*; D006657:Histones / Q000235:genetics*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009154:Mutation; D059906:Neuroimaging; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics; D003336:Tectum Mesencephali / Q000000981:diagnostic imaging; D055815:Young Adult
D006657:Histones