Clinical Significance of Molecular Genetic Analysis in Diffuse Intrinsic Pontine Glioma: Two Case Reports.

The prognosis of diffuse intrinsic pontine glioma (DIPG) is dismal, with no established curative treatments. While DIPG frequently harbors diagnostically significant H3F3A mutations, it typically lacks molecularly targetable genetic abnormalities. Due to the tumor's location and the associated risks of morbidity and mortality from tissue sampling, standard care has traditionally relied on clinical symptoms and imaging for diagnosis and treatment decisions-even at recurrence-without biopsy. Herein, we present two cases of DIPG in which biopsy of disseminated lesions at recurrence revealed clinically significant genetic alterations, including high tumor mutational burden or a germline TP53 mutation. These findings underscore the potential clinical value of molecular genetic analysis from biopsied tissues, which may inform treatment decisions and guide patient management.