Hypofractionated radiotherapy combined with bevacizumab plus low-dose ifosfamide, carboplatin, and etoposide as second-line chemoradiotherapy for progressing spinal diffuse midline glioma, H3K27-altered: illustrative case.

BACKGROUND: Spinal cord diffuse midline glioma (DMG) is a relatively rare disease with a poor prognosis and no effective treatment. OBSERVATIONS: A 45-year-old man presented with rapidly progressive paraplegia in both lower extremities, along with bladder and bowel disturbance. Spinal magnetic resonance imaging (MRI) showed a heterogeneously contrast-enhanced mass at the T1-4 levels. A biopsy via T1-4 decompressive laminectomy with expansive duraplasty was performed. The histopathological diagnosis was DMG, H3K27-altered, World Health Organization grade 4. Radiation plus concomitant temozolomide was started; however, follow-up MRI showed tumor progression. Additional hypofractionated radiotherapy (HFRT; 24 Gy/5 fractions) was performed, with bevacizumab (BEV) plus low-dose ifosfamide-carboplatin-etoposide (ICE) as second-line treatment. One month later, MRI showed tumor regression with significant improvement in the peritumoral edema. The chemotherapy regimen was repeated every 4-6 weeks, and the patient remained stable. After 13 courses of chemotherapy, the size of the spinal DMG increased markedly, with dissemination to the temporal lobe. The patient died approximately 21 months after the initial diagnosis. LESSONS: Spinal DMG is a malignant tumor with a poor prognosis. However, treatment with additional HFRT combined with BEV plus low-dose ICE may inhibit tumor progression to prolong the progression-free period and survival. https://thejns.org/doi/10.3171/CASE2464.

Trochlear nerve schwannoma with concomitant osimertinib-responsive stage IV lung adenocarcinoma: illustrative case.

BACKGROUND: The prognosis for cancer patients has been improved because of the development of molecularly targeted drugs. Treatment of intracranial tumors must be personalized while prioritizing the treatment of comorbid cancers. OBSERVATIONS: A 38-year-old man presented with bloody sputum, bilateral multiple nodules, and a mass in the lower lobe of his right lung. Bronchoscopy revealed stage IV lung adenocarcinoma with an epidermal growth factor receptor (EGFR) mutation. Screening head magnetic resonance imaging revealed a 38-mm-diameter mass in the left petroclival area. Because the patient was neurologically intact, the treatment of lung adenocarcinoma was prioritized, and the third-generation EGFR-tyrosine kinase inhibitor osimertinib was used. Although nodules in the lung began to shrink, the intracranial lesion expanded and caused hydrocephalus, necessitating a ventriculoperitoneal shunt. The tumor also caused diplopia, dysarthria, and gait abnormalities. A left anterior transpetrosal approach was used to remove the tumor derived from the trochlear nerve. The pathological examination revealed schwannoma. Neurological symptoms improved following surgery. Osimertinib was continued during the perioperative period. LESSONS: Osimertinib was effective for lung adenocarcinoma but not for trochlear nerve schwannoma, which required surgical intervention. It is necessary to tailor the treatment of benign brain tumors in patients with concurrent malignant cancers. https://thejns.org/doi/10.3171/CASE24144.