1. Pathologic features of brain hemorrhage after radiation treatment: case series with somatic mutation analysis.
- Author
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Alcazar-Felix RJ, Srinath A, Hage S, Bindal A, Ressler A, Pytel P, Allaw S, Girard R, Marchuk DA, Awad IA, and Polster SP
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Young Adult, Biopsy, Cerebral Hemorrhage genetics, Cerebral Hemorrhage etiology, Cerebral Hemorrhage pathology, Class I Phosphatidylinositol 3-Kinases genetics, Cranial Irradiation adverse effects, Databases, Factual, DNA Mutational Analysis, Genetic Predisposition to Disease, High-Throughput Nucleotide Sequencing, Intracranial Arteriovenous Malformations genetics, Intracranial Arteriovenous Malformations radiotherapy, Intracranial Arteriovenous Malformations pathology, Intracranial Hemorrhages genetics, Intracranial Hemorrhages etiology, Intracranial Hemorrhages pathology, Phenotype, PTEN Phosphohydrolase genetics, Retrospective Studies, Risk Factors, Mutation, Radiation Injuries genetics, Radiation Injuries pathology, Radiation Injuries etiology
- Abstract
Background: Radiation treatment for diseases of the brain can result in hemorrhagic adverse radiation effects. The underlying pathologic substrate of brain bleeding after irradiation has not been elucidated, nor potential associations with induced somatic mutations., Methods: We retrospectively reviewed our department's pathology database over 5 years and identified 5 biopsy specimens (4 patients) for hemorrhagic lesions after brain irradiation. Tissues with active malignancy were excluded. Samples were characterized using H&E, Perl's Prussian Blue, and Masson's Trichrome; immunostaining for B-cells (anti-CD20), T-cells (anti-CD3), endothelium (anti-CD31), macrophages (anti-CD163), α-smooth muscle actin, and TUNEL. DNA analysis was done by two panels of next-generation sequencing for somatic mutations associated with known cerebrovascular anomalies., Results: One lesion involved hemorrhagic expansion among multifocal microbleeds that had developed after craniospinal irradiation for distant medulloblastoma treatment. Three bleeds arose in the bed of focally irradiated arteriovenous malformations (AVM) after confirmed obliteration. A fifth specimen involved the radiation field distinct from an irradiated AVM bed. From these, 2 patterns of hemorrhagic vascular pathology were identified: encapsulated hematomas and cavernous-like malformations. All lesions included telangiectasias with dysmorphic endothelium, consistent with primordial cavernous malformations with an associated inflammatory response. DNA analysis demonstrated genetic variants in PIK3CA and/or PTEN genes but excluded mutations in CCM genes., Conclusions: Despite pathologic heterogeneity, brain bleeding after irradiation is uniformly associated with primordial cavernous-like telangiectasias and disruption of genes implicated in dysangiogenesis but not genes implicated as causative of cerebral cavernous malformations. This may implicate a novel signaling axis as an area for future study., Competing Interests: Declaration of competing interest Drs. Awad and Marchuk receive grant funding from the U.S. National Institutes of Health and the Department of Defense. Dr. Awad is a consultant to Neurelis, Inc. The other authors report no conflicts, (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
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