TY - JOUR
T1 - High-Grade Astrocytoma with Piloid Features
T2 - A Dual Institutional Review of Imaging Findings of a Novel Entity
AU - Soni, Neetu
AU - Agarwal, Amit
AU - Ajmera, Pranav
AU - Mehta, Parv
AU - Gupta, Vivek
AU - Vibhute, Mukta
AU - Gubbiotti, Maria
AU - Mark, Ian T.
AU - Messina, Steven A.
AU - Mohan, Suyash
AU - Bathla, Girish
N1 - Publisher Copyright:
© 2024 American Society of Neuroradiology. All rights reserved.
PY - 2024/4/1
Y1 - 2024/4/1
N2 - High-grade astrocytoma with piloid features (HGAP) is a recently identified brain tumor characterized by a distinct DNA methylation profile. Predominantly located in the posterior fossa of adults, HGAP is notably prevalent in individuals with neurofibromatosis type 1. We present an image-centric review of HGAP and explore the association between HGAP and neurofibromatosis type 1. Data were collected from 8 HGAP patients treated at two tertiary care institutions between January 2020 and October 2023. Demographic details, clinical records, management, and tumor molecular profiles were analyzed. Tumor characteristics, including location and imaging features on MR imaging, were reviewed. Clinical or imaging features suggestive of neurofibromatosis 1 or the presence of NF1 gene alteration were documented. The mean age at presentation was 45.5 years (male/female ¼ 5:3). Tumors were midline, localized in the posterior fossa (n ¼ 4), diencephalic/thalamic (n ¼ 2), and spinal cord (n ¼ 2). HGAP lesions were T1 hypointense, T2-hyperintense, mostly without diffusion restriction, predominantly peripheral irregular enhancement with central necrosis (n ¼ 3) followed by mixed heterogeneous enhancement (n ¼ 2). Two NF1 mutation carriers showed signs of neurofibromatosis type 1 before HGAP diagnosis, with one diagnosed during HGAP evaluation, strengthening the HGAP-NF1 link, particularly in patients with posterior fossa masses. All tumors were IDH1 wild-type, often with ATRX, CDKN2A/B, and NF1 gene alteration. Six patients underwent surgical resection followed by adjuvant chemoradiation. Six patients were alive, and two died during the last follow-up. Histone H3 mutations were not detected in our cohort, such as the common H3K27M typically seen in diffuse midline gliomas, linked to aggressive clinical behavior and poor prognosis. HGAP lesions may involve the brain or spine and tend to be midline or paramedian in location. Underlying neurofibromatosis type 1 diagnosis or imaging findings are important diagnostic cues.
AB - High-grade astrocytoma with piloid features (HGAP) is a recently identified brain tumor characterized by a distinct DNA methylation profile. Predominantly located in the posterior fossa of adults, HGAP is notably prevalent in individuals with neurofibromatosis type 1. We present an image-centric review of HGAP and explore the association between HGAP and neurofibromatosis type 1. Data were collected from 8 HGAP patients treated at two tertiary care institutions between January 2020 and October 2023. Demographic details, clinical records, management, and tumor molecular profiles were analyzed. Tumor characteristics, including location and imaging features on MR imaging, were reviewed. Clinical or imaging features suggestive of neurofibromatosis 1 or the presence of NF1 gene alteration were documented. The mean age at presentation was 45.5 years (male/female ¼ 5:3). Tumors were midline, localized in the posterior fossa (n ¼ 4), diencephalic/thalamic (n ¼ 2), and spinal cord (n ¼ 2). HGAP lesions were T1 hypointense, T2-hyperintense, mostly without diffusion restriction, predominantly peripheral irregular enhancement with central necrosis (n ¼ 3) followed by mixed heterogeneous enhancement (n ¼ 2). Two NF1 mutation carriers showed signs of neurofibromatosis type 1 before HGAP diagnosis, with one diagnosed during HGAP evaluation, strengthening the HGAP-NF1 link, particularly in patients with posterior fossa masses. All tumors were IDH1 wild-type, often with ATRX, CDKN2A/B, and NF1 gene alteration. Six patients underwent surgical resection followed by adjuvant chemoradiation. Six patients were alive, and two died during the last follow-up. Histone H3 mutations were not detected in our cohort, such as the common H3K27M typically seen in diffuse midline gliomas, linked to aggressive clinical behavior and poor prognosis. HGAP lesions may involve the brain or spine and tend to be midline or paramedian in location. Underlying neurofibromatosis type 1 diagnosis or imaging findings are important diagnostic cues.
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U2 - 10.3174/ajnr.A8166
DO - 10.3174/ajnr.A8166
M3 - Article
C2 - 38485198
AN - SCOPUS:85189906332
SN - 0195-6108
VL - 45
SP - 468
EP - 474
JO - American Journal of Neuroradiology
JF - American Journal of Neuroradiology
IS - 4
ER -