Rui R1*, Bruno C2, Susana N3, Luísa S4, Roberto S5, Jorge L6, Lígia O7, João GCM3, Rui V2 and Josué P2
1Department of Neurosurgery, Centro Hospitalar de Vila Nova de Gaia, Portugal
2Department of Neurosurgery, Centro Hospitalar Universitário de S. João, Portugal
3Department Pediatric Oncology, Centro Hospitalar Universitário de S. João, Portugal
4Department Of Neuroradiology, Centro Hospitalar Universitário de S. João, Portugal
5Department of Anatomical Pathology, Centro Hospitalar Universitário de S. João, Portugal
6Institute of Molecular Pathology and Immunology of the University of Porto (Ipatimup), Portugal
7Department of Radiotherapy, Centro Hospitalar Universitário de S. João, Portugal
Background: Diffuse Midline Glioma (DMG) H3 K27M-mutant of the pons is the most common pediatric brainstem tumor, leading to poor outcome. Radiotherapy is the only proved therapeutic option that offers temporary benefit, while co-adjuvant chemotherapy is still controversial. Although MRI allows for the diagnosis of DMG, biopsy is the gold standard as it offers additional molecular biology information that can be useful for future targeted immune or chemotherapy.
Case Report: A 6-year-old girl presented with a 6 months history of vomits, ataxia with frequent falls, left peripheral facial palsy and headache plus irritability. Brain MRI showed an intra-axial lesion in the mesencephalon and pons, hypointense in T1, hyperintense in T2 and FLAIR, without contrast enhancement. The dysmorphic pons partly surrounded the basilar artery, obstructing the upper part of the 4th ventricle and aqueduct, with supratentorial ventricular dilatation. A transfrontal stereotactic biopsy of the lesion was performed followed by an Endoscopic Third Ventriculostomy (ETV). Histology and biology confirmed the diagnosis of H3 K27M-mutant DMG.
Conclusion: Biopsy is an invasive procedure – however, it should be offered to children with presumptive imaging of DMG. It shows low morbidity, confirms the diagnosis and has potential utility for research on targeted chemotherapy or immunotherapy for secondary treatment approach.
Diffuse midline glioma; Stereotactic biopsy; Molecular diagnosis; Targeted chemotherapy
Rui R, Bruno C, Susana N, Luísa S, Roberto S, Jorge L, et al. Diffuse Midline Glioma, H3 K27M-Mutant of the Pons-Multidisciplinary Approach. Clin Oncol. 2021;6:1827..