Midbrain radiation-induced cavernous malformation after treatment for Pontine Glioma: A case report

Adult brainstem gliomas are rare tumors, with concurrent radiation therapy (RT) and temozolomide being the standard treatment approach. Another uncommon condition, adult brainstem radiation-induced cavernous malformation (RICM), presents a significant risk of hemorrhage and focal neurological deficits. While surgery is typically recommended for symptomatic RICM, its location in the brainstem makes the procedure riskier. We report a case of a brainstem glioma treated with chemoradiation, followed by the development of a brainstem RICM 10 years later. The patient was monitored with routine imaging follow-ups, demonstrating stable clinical and radiographic findings. A 36-year-old woman experienced dizziness, unsteady gait, and paresthesia for 2–3 months. Brain magnetic resonance imaging (MRI) in October 2014 revealed an infiltrative brainstem tumor. Biopsy confirmed a WHO grade 3 anaplastic astrocytoma. The primary treatment consisted of concurrent RT, 56 Gray (Gy) over 28 fractions, along with temozolomide. Adjuvant temozolomide therapy was continued for 10 years. In October 2024, a follow-up MRI showed a new cavernous malformation (CM) in the midbrain. Owing to the patient’s stable neurological status, continued observation with imaging surveillance was chosen. This case highlights our experience in treating adult brainstem glioma and brainstem RICM. There is no established consensus on the standard management for these uncommon conditions. The treatment strategies employed in our case appeared to contribute to favorable long-term survival for the brainstem glioma and short-term stable condition for the brainstem RICM. Further studies are necessary to develop a standardized approach to treating these rare diseases.