Metastatic brain lesions
Brain metastasis is a common complication of cancer. According to the results of recent population studies, almost 20% of adult cancer patients will experience metastasis to the brain from their primary tumor during their lifetime. The incidence of primary brain metastasis varies greatly depending on the type of primary tumor; the highest incidence is observed in lung cancer (20%), as well as melanoma (7%), kidney cancer (6.5%), breast cancer (5%), and colorectal cancer (1.8%). The least frequent brain metastasis is observed in prostate cancer, malignant neoplasms of the female reproductive system, head and neck area, and non-melanomatous skin cancer.
Symptoms
Manifestations of metastatic brain lesions can be divided into focal and systemic. Focal symptoms such as hemiparesis, aphasia, and visual field narrowing may vary significantly depending on the tumor location. Systemic manifestations such as headache, decreased consciousness (lethargy, stupor, coma), nausea, and vomiting are the result of increased intracranial pressure (ICP) or hydrocephalus. Metastatic lesions of the paraventricular regions of the brain may cause the development of obstructive hydrocephalus due to impaired normal CSF outflow from the 1st and 4th ventricles. Obstructive hydrocephalus is most pronounced when tumors are located in the posterior cranial fossa. Headaches caused by increased ICP and/or worsening hydrocephalus have the following characteristics:
- most pronounced in the morning and in the supine position;
- accompanied by nausea and vomiting;
- increased by coughing and exertion;
- may be accompanied by confusion or decreased consciousness.
Increased ICP is very often accompanied by optic disc edema, but the absence of this symptom does not allow us to completely exclude increased ICP.