Carcinomatous meningitis is a lesion of the meninges by metastases of a cancerous tumor. It occurs during the dissemination of tumor cells, has a small focal diffuse character. It is clinically manifested by symptoms of meningitis with cranial nerve dysfunction, a disorder of consciousness. Carcinomatous meningitis is diagnosed based on the results of analysis of cerebrospinal fluid, cerebral MRI data. Palliative treatment: symptomatic (antiemetics, diuretics, anticonvulsants, glucocorticosteroids), chemotherapeutic (methotrexate), radiation.
ICD 10
C70 Malignant neoplasm of the meninges
General information
The name “carcinomatosis” means metastasis of carcinoma. Synonymous names are neoplastic meningitis, leptomeningeal metastases, carcinomatosis of the cerebral membranes. Metastases to the brain membranes are observed in 5-8% of cases of all malignant tumors. Melanomas and bronchogenic carcinomas most often metastasize into the shells. In 50% of patients, the manifestation of meningitis is the first clinical manifestation of the dissemination of the oncological process. In some cases, carcinomatous meningitis outstrips even the appearance of clinical symptoms caused by primary cancer.
Causes
The source of metastases are malignant neoplasms of various localization and histological type. The primary focus is more often lung cancer, bronchial carcinoma, breast cancer, melanoma, less often stomach cancer, hepatocellular carcinoma, kidney cancer. Tumor cells of primary formation enter the cerebral membranes with blood flow. Usually, a multi-focal lesion occurs, which is widespread or limited to a certain area. In half of cases, carcinomatous meningitis is combined with the simultaneous formation of metastases in the substance of the brain, in 65% of cancer patients — with metastasis to internal organs.
Pathogenesis
Cancer cells trapped in the cerebral membranes multiply in the tissues of the membranes, the leptomeningeal space. Irritation of the membranes causes the occurrence of the classic meningeal syndrome. The formation of metastatic foci in the subcranial space filled with cerebrospinal fluid (CSF) leads to impaired cerebrospinal circulation, intracranial hypertension occurs. As a result of the difficulty of the cerebrospinal fluid outflow, hydrocephalus is formed. The increasing increase in intracranial pressure causes the development of life-threatening complications: cerebral edema, dislocation of brain structures.
Symptoms
In typical cases, there is a gradual aggravation of neurological symptoms. Basic clinical manifestations: headache, nausea, disorders of the cranial nerves, disorders of consciousness, epileptic paroxysms, ataxia. The headache is intense, accompanied by vomiting, independent of food intake, which does not bring relief to the patient. Oculomotor disorders, facial nerve paresis, difficulty swallowing, voice changes (dysphonia) and speech (dysarthria) are possible.
Transient psychomotor agitation is replaced by lethargy, a drowsy state. With concomitant intracerebral lesion, the corresponding focal symptoms occur. Meningeal syndrome, in addition to intense cephalgia, is manifested by hyperesthesia (hypersensitivity to sounds, light, touch), tonic phenomena: rigidity (tonic tension) of the occipital muscles, forced posture of the patient with bent and brought to the trunk limbs, head thrown back.
Complications
Progressive carcinomatous process causes severe disturbances of consciousness up to coma. Increasing intracranial hypertension, hydrocephalus are complicated by the development of cerebral edema. As a result of the mass effect, there is a displacement of cerebral structures in the direction of the large occipital foramen. There is a danger of compression of the cerebral trunk, vital regulatory centers located in it: cardiovascular, respiratory. The latter complication is often the cause of death of the patient.
Diagnostics
It is not easy to diagnose carcinomatous meningitis, since its symptoms are similar to meningitis of another etiology. The clinic simulating the shell carcinomatous process occurs in cancer patients due to the development of paraneoplastic syndrome, dysmetabolic disorders caused by cancerous lesions of internal organs. In some cases, neurological symptoms are a complication of chemotherapeutic and radiological treatment of the primary tumor focus. Therefore, the diagnosis cannot be established by a neurologist solely on clinical grounds. The following additional studies are needed:
- MRI of the brain. Diagnoses hydrocephalus, in the presence of a mass effect — displacement of brain structures. Determines the increase in the density of the shells, the presence of small foci in them. MRI with contrast is more informative, which allows detecting the accumulation of contrast in the shell tissues, subarachnoid spaces.
- Lumbar puncture. It is carried out for the collection of cerebrospinal fluid only after the exclusion of edema and dislocation according to MRI data. Examination of the cerebrospinal fluid reveals an increase in protein concentration without the presence of inflammatory changes. Detection of cancer cells at the first puncture reaches 45-50%. In case of a negative result, repeated punctures are performed to help determine the presence of malignant cells in another 40% of patients.
The lack of the possibility of tomographic neuroimaging dictates the need for echoencephalography. The examination does not allow to establish the topic and the genesis of the lesion, but makes it possible to assess the degree of intracranial hypertension, to identify dislocation syndrome. Carcinomatous meningitis should be differentiated with the shell form of neuroleukosis, infectious meningitis, meningoencephalitis.
Treatment
Since meningeal metastases are the result of cancer dissemination, only palliative therapy is possible. It consists in the treatment of cytostatic chemotherapy, radiotherapy and a combination of these techniques.
- Chemotherapy. Methotrexate has proven itself well as the drug of choice. In parallel with systemic chemotherapy, local cytostatic administration can be performed, carried out endolumbally or by ventricular puncture.
- Radiotherapy. It is necessary to irradiate the entire brain. The recommended total dose is 30-40 g. Treatment is carried out by separate procedures for 2-4 weeks.
Taking into account the clinical manifestations, symptomatic therapy is carried out. Antiemetic drugs are used to stop vomiting, diuretics are used to lower intracranial pressure, prevention of brain edema is carried out by a combination of diuretics with corticosteroids. Convulsive syndrome is an indication for the appointment of anticonvulsants, with psychomotor agitation, the introduction of sedatives is necessary.
Prognosis and prevention
In the absence of therapy, carcinomatous meningitis within two months becomes the cause of death of the patient. Correct palliative treatment can lead to temporary partial remission, prolong the life of patients up to 6 months on average. Life expectancy of more than 12 months since the diagnosis of the disease was observed in only 15% of patients. 50% of deaths are associated with central nervous system damage, 50% – with pathology of internal organs. Oncological alertness of patients and doctors is of great preventive importance, since it is possible to prevent the carcinomatous process by timely detection and radical treatment of the primary neoplasm.
