Hemangioblastoma is a benign brain tumor originating in blood vessels with a predominant localization in the cerebellum. Clinical symptoms depend on its location and may include headaches, dizziness, nausea, asthenia, congestive optic nerve discs, cerebellar syndrome (ataxia, nystagmus, muscular hypotension, intentional tremor), motor and sensory disorders, disorders of the function of cranial nerves and pelvic organs. The basis for the diagnosis is an MRI of the brain and a histological examination of a tumor sample. The most effective treatment for hemangioblastoma is its complete removal.
D33 Benign neoplasm of the brain and other parts of the central nervous system
Hemangioblastoma accounts for about 2% of all tumors located in the skull. Hemangioblastoma is most often observed in patients aged 40 to 60 years. In 10% of cases, hemangioblastoma is a manifestation of inherited Hippel-Lindau disease — phacomatosis, characterized by multiple neoplasms of internal organs that occur during life (pancreatic cysts, pheochromocytoma, renal cell carcinoma, retinal angioma, etc.). In such cases, hemangioblastoma is usually diagnosed at the age of 20-30 years.
Like other neoplasms of the nervous system (craniopharyngioma, astrocytoma of the brain, ganglioneuroma, ganglioneuroblastoma, meningioma, etc.), hemangioblastoma can develop as a result of exposure to various carcinogenic factors on the body. The latter include ionizing radiation, increased insolation, contact with industrial carcinogenic substances (asbestos, benzene, vinyl chloride, petroleum and coal tar, phenol formaldehyde, etc.), oncogenic viruses (for example, retroviruses, adenoviruses, herpes virus). Hemangioblastoma, which is part of Hippel-Lindau disease, has a hereditary etiology and is associated with a genetic mutation in the third chromosome, leading to a violation of the synthesis of a tumor suppressor. It is inherited in an autosomal dominant way.
According to the macroscopic structure in neurology, there are 3 groups of hemangioblastomas: solid, cystic and mixed. A solid (soft-tissue) hemangioblastoma consists of tumor cells assembled into a single node surrounded by a capsule, having a soft consistency and dark cherry color. It accounts for about 65% of all hemangioblastomas. Cystic hemangioblastoma is a smooth-walled cyst. In most cases, there is a small solid nodule on the cyst wall. In about 4-5% of cases, hemangioblastomas of a mixed type occur, characterized by the presence of a solid node, inside which numerous cysts are located.
According to the microscopic (histological) structure, the following variants of hemangioblastoma are distinguished: juvenile, transitional and pure cell. Juvenile hemangioblastoma consists mainly of thin-walled capillaries that are closely adjacent to each other. Transitional hemangioblastoma contains approximately equal proportions of capillaries and stromal cells. Pure cell hemangioblastoma is distinguished by numerous yellowish cells located on pathologically altered vessels.
Clinical manifestations of hemangioblastoma depend on its localization. Hemangioblastoma is extremely rare as an intracerebral tumor of the cerebral hemispheres. In 80-85% of cases, it affects the hemispheres of the cerebellum, much less often — its worm. According to various data, hemangioblastoma of the spinal cord occurs in 3-13% of cases, hemangioblastoma of the medulla oblongata in 2-3% of cases.
The clinical picture of cerebellar hemangioblastoma consists of general cerebral, cerebellar and distant symptoms. The general cerebral symptoms of hemangioblastoma are caused by a violation of the outflow of cerebrospinal fluid and increasing hydrocephalus. Headache is characteristic, which practically does not disappear against the background of taking analgesics and vasodilating drugs. It can affect any area, but is more often localized in the back of the head. During ophthalmoscopy in the early stages of hamangioblastoma, stagnant discs of the optic nerves are detected. Often there is a so-called “stagnant” labyrinthitis, accompanied by intense systemic dizziness, nausea and vomiting. Labyrinthitis of stagnant genesis and associated vestibular ataxia require differentiation of hemangioblastoma from inflammatory lesions of the inner ear with otitis media, functional disorders with aerotitis, toxic damage to the labyrinth with ear cholesteatoma, Meniere’s disease and vascular disorders (chronic cerebral ischemia).
It should be noted that the general cerebral symptoms can be so pronounced that it is difficult to detect the cerebellar syndrome itself, which significantly complicates the diagnosis of hemangioblastoma. This is mixed with a variety of distant symptoms of hemangioblastoma, including cranial nerve paralysis, convulsive syndrome, pyramidal disorders (paresis or paralysis); less often there are sensitivity disorders.
The symptom of cerebellar lesion in hemangioblastoma is primarily cerebellar ataxia. Cerebellar worm hemangioblastoma is manifested by static ataxia, i.e., a disorder of posture and walking. Typical are shakiness or falling in the Romberg pose, a forced tilted head position, a “drunken” gait, lateropulsion (deviation of the body to the side) when walking, a violation of movement synchronization (assinergia). When hemangioblastoma is localized in the cerebellar hemisphere, dynamic ataxia (impaired coordination of movements) prevails, which is detected using finger-nasal and knee-heel tests. As for other tumors of the cerebellum, excessive disproportionately sweeping movements (dysmetry), too large handwriting (megalography), disorder of rapid change of movements (adiadochokinesis), slow chanted speech (articulatory ataxia) are typical. Other signs of damage to the cerebellum include nystagmus, muscle hypotension, intentional tremor.
At the beginning of the development of cerebellar hemangioblastoma, disorders are noted only on the side of the tumor localization. However, as the hemangioblastoma grows, it begins to squeeze the opposite hemisphere of the cerebellum and the process takes on a bilateral character. The addition of symptoms of damage to the cerebellar worm resulting from its compression leads to the development of total cerebellar syndrome. In the later stages, hemangioblastoma is often accompanied by mental disorders, often in the form of asthenia, depressive neurosis or neurasthenia, and impaired consciousness in the form of deafness.
Hemangioblastoma of the spinal cord and cerebral hemispheres is manifested by disorders of sensitivity and motor sphere corresponding to its localization, as well as disorders of bowel and bladder function.
Difficulties in the diagnosis of hemangioblastoma are associated with the non-specificity of its clinical manifestations, masking neurological deficit and cerebellar syndrome under pronounced cerebral symptoms. A thorough neurological examination and an additional consultation with an ophthalmologist, during which stagnant optic nerve discs are detected, make it possible to suspect the presence of intracranial volumetric formation. At the same time, in addition to the usual initial examination in the form of EEG, REG and Echo-EG, the patient must necessarily undergo an MRI of the brain.
In most cases, the study of layered horizontal and sagittal sections obtained during MRI allows to establish the localization of the tumor process and differentiate it from a brain abscess, intracerebral hematoma, a focus of demyelination in multiple sclerosis, the consequences of severe traumatic brain injury, brain cysts Final diagnosis of hemangioblastoma and determination of its microscopic type are possible only after histological examination a sample of the tumor. The tumor tissues necessary for the study can be obtained as a result of stereotactic brain biopsy or during surgery to remove the tumor.
The only radical treatment for hemangioblastoma is its complete removal. As an operative access, a craniotomy is used with the removal of the occipital bone in the region of the large occipital foramen and resection of the arch of the I cervical vertebra. Then a complete removal of the solid tumor node is performed. With the cystic nature of hemangioblastoma, the removal of the node is combined with aspiration of the cyst contents, the walls of which often do not require removal.
Removal of a cerebellar tumor can be carried out in an emergency when the cerebellum is inserted into the large occipital foramen and compression of the brain stem. In such cases, to reduce intracranial pressure, a puncture of the lateral ventricle is pre-performed. If during the operation only partial removal of hemangioblastoma is possible, which does not provide normal cerebrospinal fluid outflow from the cranial cavity, then bypass surgery is additionally performed: ventriculostomy, external vetricular drainage or ventriculoperitoneal bypass.
Radiation therapy can be used in the presence of contraindications to surgical treatment, in the case of multiple hemangioblastoma, or as an anti-relapse treatment with incomplete removal.
The benign nature of hemangioblastoma provides a favorable prognosis with its complete removal, which is possible in 80-85% of the disease. Partial removal of tumor cells of a solid node leads to postoperative recurrence of the tumor. The diagnosis of Hippel-Lindau disease in a patient worsens the prognosis of hemangioblastoma.