2025 Volume 53 Issue 5 Pages 339-345
Gamma knife surgery is an established treatment for arteriovenous malformations. Although known long-term complications of this surgery include radiation-induced vascular changes such as cavernous malformations, cysts, and chronic expanding hematomas, the simultaneous development and progression of all three in an adult patient is extremely rare.
We present the case of a 33-year-old man who underwent radiosurgery for a large arteriovenous malformation in the right parietal region, with complete obliteration being confirmed three years post-treatment. Thirteen years later, magnetic resonance imaging (MRI) revealed a small perilesional cyst that remained stable for several years. Twenty-four years after treatment, the patient developed seizures, and imaging demonstrated enlargement of the cyst along with a new mass-like lesion. One year later, the patient experienced progressive left-leg weakness and worsening cerebral edema. Surgical removal was performed due to worsening symptoms. Intraoperative findings revealed a lesion composed of a cavernous malformation, a chronic hematoma, and a cyst. Gross total resection was achieved. Histological examination confirmed the diagnosis of a cavernous malformation. Postoperatively, the patient’s symptoms improved, and he returned to independent daily life.
This case highlights an exceptionally rare report in which all three pathologies were simultaneously identified in an adult patient treated for radiation-induced cavernous malformation. The accumulation of similar reports is crucial for a better understanding of long-term risks and for establishing appropriate surveillance strategies.
