A case of more than 20 years survival with glioblastoma, and development of cavernous angioma as a delayed complication of radiotherapy

Glioblastoma (GBM) is the most common malignant CNS neoplasm, the prognosis of which remains poor even after multidisciplinary treatment. The 5-year overall survival rate of GBM is less than 10% and has remained unchanged for more than 50 years. Because GBM patients rarely survive over a decade, only very few cases of delayed complications caused by therapy have been reported. Here, we report the case of a 24-year-old man who is still alive 21 years after surgical resection and chemoradiotherapy for GBM. This patient developed a cavernous angioma 19 years after the initial surgery as a delayed complication of radiotherapy. The diagnosis of the initial tumor was confirmed by histopathological review, which indicated that the tumor had immunohistochemical and genetic profiles consistent with GBM. Long-term survival in the case of this GBM patient likely resulted from a combination of factors, including hypermethylation of the MGMT (O6-methyl guanine methyl transferase) CpG island, young age at diagnosis, good performance status, and complete surgical resection of the tumor. To the best of our knowledge, this case report describes one of the longest-surviving GBM patients and is the first on radiation-induced cavernous angioma in a GBM patient.