Brain metastases arise from cancer cells that have detached from other primary tumors and settled in the brain.
A metastasis is the colonization of tumor cells from another primary tumor. In the brain, this occurs "hematogenously" via the bloodstream, "lymphogenically" via lymphatic channels or via the cerebrospinal fluid (CSF). One third of all brain tumors are metastases; they develop in 8 out of 100,000 people per year.
The original primary tumor is usually located in the lung (bronchial carcinoma), mammary gland (breast carcinoma) or skin (melanoma). However, other localizations are also possible, such as colon (colon/rectal carcinoma), esophagus and stomach (esophageal and gastrointestinal carcinoma), or blood (lymphoma).
The symptoms of brain metastases depend on their localisation. They can include headaches, but also spinal pain, impaired mental abilities (neurocognitive deficits), speech disorders, epileptic seizures, paralysis or gait disorders. Metastases can already become noticeable when the primary tumour is still inconspicuous - and a delayed appearance is also possible, sometimes only years after the supposedly successful therapy of a cancer.
After the diagnosis has been made, interdisciplinary - i.e. joint neurosurgical and oncological - advice is given on the best possible therapy. In the case of tissue sampling and/or metastasis removal, surgery is performed with the addition of "high-tech procedures" such as intraoperative neuronavigation in combination with high-resolution surgical microscopes, intraoperative imaging using magnetic resonance imaging (MRI) or ultrasound, and neurophysiological monitoring.
