Distant metastasis of intracranial solitary fibrous tumor preceding resection: illustrative case.

backgroundPostsurgical distant metastasis of intracranial solitary fibrous tumors (ISFTs) is not uncommon and often leads to poor prognosis. However, presurgical distant metastasis has not been previously reported. OBSERVATIONS: This case details a male patient who presented with seizures at age 26 years. Diagnosed with a space-occupying lesion in the right temporal lobe, suspected to be a meningioma, he underwent Gamma Knife treatment. Seven years later, MRI revealed slight growth of the lesion, leading to another Gamma Knife procedure. At age 40 years, the patient developed a tumor on the left chest wall, requiring total resection and rib reconstruction. Pathology confirmed it was a solitary fibrous tumor. At age 41 years, he experienced headaches and epilepsy, with MRI showing an enlarged lesion in the right temporal lobe with peritumoral edema, necessitating surgery. Pathological analysis confirmed an ISFT. LESSONS: ISFTs can metastasize distantly over time, even without surgery. Differentiating ISFT from meningioma via imaging is challenging. Therefore, Gamma Knife treatment without definitive pathological diagnosis requires careful follow-up, monitoring both the intracranial tumor and peripheral organs for potential metastasis. https://thejns.org/doi/10.3171/CASE24846.