Other primary tumors that can metastasize to the brain include melanoma, sarcoma, and tumors from the kidneys, as well as the large intestine. Sometimes the primary focus that gives metastasis to the brain is difficult to determine. At the same time, it is worth noting that brain metastases are more common than the primary brain tumors themselves. In some cases, brain metastases may be the first clinical manifestations of the underlying cancer. For example, about 10% of lung cancer patients see a doctor for the first time due to neurological disorders.
Metastases to the brain can spread in several ways - by infiltration into the surrounding tissues, but most often through the bloodstream and through the lymphatic pathways. A single metastasis or multiple brain damage may also be detected.
Modern methods of examination of the central nervous system allowed us to find out that currently the incidence of metastatic brain tumors is about 14 cases per 100,000 population per year, i.e. exceeds the incidence of primary brain tumors.
Clinical manifestations of brain metastases.
The symptoms depend on the size of the intracranial tumor foci, their number and location. In principle, clinical symptoms can be divided into local, due to the location of the tumor in a specific part of the brain responsible for certain functions of a certain organ, and general brain symptoms associated with the size of additional tumor tissue that interferes with the functioning of the brain itself. For example, a tumor near the structures that provide the innervation of the eye will manifest itself as a loss of visual fields, when the eye does not perceive certain areas of the field of view. A lot of small nodes will give a picture of brain edema, because the extra grams of the tumor in the closed cranium interfere with the normal circulation of fluids and squeeze normal tissues. In half of the patients, secondary brain neoplasms respond with a headache. Over time, the growth of metastases will make the pain permanent, and the closeness of the space will lead to unbearable intensity. Vertigo and double vision are not uncommon when viewed with both eyes. Every fifth patient develops motor disorders up to the paresis of half of the body. Every sixth person suffers from intellectual abilities, the same number suffers from changes in behavior, disorders of movement and gait, a little less often there are convulsions, but a completely asymptomatic course, when metastatic formations are detected only during examination, is also not uncommon. Edema of the tissue around the tumor-perifocal edema, coupled with increased intracranial pressure (ICP), cause general cerebral symptoms with headache, dizziness, double vision, and sometimes vomiting. Apoplexy, similar to a stroke, develops acutely and is manifested by focal disorders-evidence of damage to a certain area of the brain. This option, as a rule, is associated with either a blockage of the vessel, or its rupture by a tumor with subsequent hemorrhage in the brain. The remitting variant is characterized by a wave-like course, when the symptoms then decrease, then progress, resembling an atherosclerotic vascular lesion.
Clinical example # 1:
Patient K., 56 years old, went on an outpatient basis to the magnetic resonance imaging office for dizziness, unsteadiness of gait.
A history of right breast cancer, breast resection, undergoing chemotherapy.
The study of the brain by magnetic resonance imaging in various modes revealed a single metastatic lesion of the brain, localized in the left hemisphere of the cerebellum, with the presence of perifocal edema, extending to most of the cerebellum. This localization of metastasis determined the symptoms (dizziness, unsteadiness of gait).
Clinical example #2
Patient K., 61, went to the office of magnetic resonance imaging about the study of the brain, worried about headaches.
There is a history of breast cancer, surgery for the removal of the formation has not been performed, there is a diagnostic search for metastatic lesions of other organs.
Magnetic resonance imaging in various modes and three projections using intravenous contrast enhancement revealed multiple metastatic brain lesions with the presence of zones of perifocal edema.
In addition to the metastases that are obvious with native (non-contrast) scanning, intravenous contrast enhancement reveals additional foci of metastatic brain damage of smaller sizes that were not previously visualized.
Thanks to the MRI in these two examples, it was possible to determine the exact cause of headaches, dizziness and unsteadiness of gait, to determine with maximum accuracy the number of foci, the localization of the metastatic process and its prevalence, as well as to identify metastases that are not visualized by contrast-free scanning, which later determined the tactics of treatment of this disease.
After conducting the study and receiving the MRI results, the patients underwent a consultation with their attending physician and were prescribed timely chemotherapy.
In each case, the chemotherapy is specific to this picture of the disease, detected by magnetic resonance imaging. After the course (s) of chemotherapy, patients return to MRI to assess the dynamics of the disease, which is often positive (reduction in the size of the metastatic tumor, reduction in the number of metastases), as a result of timely treatment to the doctor, MRI and the appointment of adequate therapy after receiving the results of MRI.