Patient's question:
Her niece is only 6 years old this year, but she was recently diagnosed with a ventricular tumor.Doctor's answer:
Glioma and EpendymoblastomaEpendymomas originate from ependymal cells in the ventricular system of the brain, accounting for 18.2% of gliomas. They are more common in males than females and predominantly occur in children and young adults. Approximately 75% are located in the infratentorial region, while only 25% are found in the supratentorial region. Most tumors are located within the ventricles, though a few have their main mass within the brain tissue.
(1) Pathology of Ependymoma
Benign tumors are referred to as ependymomas, while malignant ones are called ependymoblastomas. Tumors take various shapes depending on their location.
(2) Clinical Manifestations of Ependymoma
Symptoms vary depending on the tumor's location. Fourth ventricle ependymomas often present with headache as the initial symptom, accompanied by dizziness and vomiting. Compelled head position may be present. When the tumor involves the upper cervical cord, neck pain and resistance may occur. As the tumor enlarges and affects the vermis of the cerebellum, balance disorders, unsteady gait, and even the inability to stand may appear. Physical examination may reveal nystagmus and papilledema. In advanced stages, rigidity and symptoms of foramen magnum herniation may develop. Third ventricle tumors can obstruct cerebrospinal fluid circulation, leading to increased intracranial pressure. Anterior third ventricle tumors may cause optic nerve compression and hypothalamic-pituitary symptoms, while posterior third ventricle tumors can result in upward gaze. Lateral ventricle tumors cause intracranial pressure elevation, sensory deficits, and hemianopia. Due to their deep location, seizures are less common. CT scans show heterogeneous high-density images, with possible calcifications or low-density cystic areas. After contrast administration, the tumor enhances in appearance.
Classification and Treatment of Gliomas
Tumors originating from neuroepithelium are collectively called gliomas (gliocytomas), accounting for 40-50% of intracranial tumors and being the most common malignant intracranial tumors. Based on pathology, they can be further classified into astrocytomas, medulloblastomas, anaplastic gliomas, ependymomas, and oligodendrogliomas.
1. Astrocytomas: The most common type of glioma, accounting for about 40%. Pathological classification includes Grade I (astrocytoma), Grade II (astrocytoma), and Grades III-IV (anaplastic glioma). Grades I-II astrocytomas are low-grade malignancies with slow onset. On CT and MRI, they appear predominantly solid or cystic with ill-defined margins, and both solid parts and cystic nodules can enhance. Clinical manifestations gradually appear depending on the lesion's location, with intracranial hypertension symptoms appearing last. Grades III-IV anaplastic gliomas have a rapid onset and are the most malignant, often growing in the cerebral hemispheres. Due to rapid growth, multiple necrotic and hemorrhagic areas may develop in the tumor center, with significant enhancement on both CT and MRI. Large areas of cerebral edema may surround the tumor.
2. Medulloblastomas: Highly malignant tumors that commonly occur in children aged 2-10, though rare cases are seen in infants under months. Most originate from the vermis of the cerebellum, extending to the fourth ventricle and cerebellar hemispheres. Due to obstruction of cerebrospinal fluid pathways, hydrocephalus is often present at diagnosis. CT and MRI can reveal posterior fossa mass lesions. MRI is recommended due to the poor visualization of this region on CT.
3. Oligodendrogliomas: Low-grade malignancies, often considered benign. They grow slowly and may contain calcified plaques within the tumor.
4. Ependymomas: Also a type of glioma, with principles similar to astrocytomas.
Most gliomas develop slowly, with symptoms appearing weeks to months before diagnosis, though some may take years. Highly malignant and posterior fossa tumors have shorter histories, while less malignant or located in quiet areas have longer histories. If the tumor bleeds or cysts, symptoms may worsen suddenly, resembling a stroke. Glioma clinical symptoms can be divided into two aspects: intracranial hypertension symptoms (e.g., headache, vomiting, visual impairment, diplopia, psychiatric symptoms) and focal symptoms caused by tumor compression, infiltration, or destruction of brain tissue (e.g., early stimulation symptoms like focal seizures, later neurological deficits like paralysis).
Embryonal Tumors of the Central Nervous System (CNS) include malignant germ cell tumors, neuroblastomas, and primitive neuroectodermal tumors (PNETs), which commonly occur in children and adolescents.
The growth characteristics of gliomas are infiltrative, with no clear boundary between the tumor and normal brain tissue. Most are not confined to a single lobe, extending outward like fingers to destroy brain tissue. Benign tumors grow slowly with longer courses, while malignant ones grow rapidly with shorter courses.
Currently, glioma treatment worldwide generally includes surgery, traditional Chinese medicine, radiotherapy, chemotherapy, X-knife, and gamma-knife.
Glioma Surgery: Surgical treatment is based on the growth characteristics of gliomas. Theoretically, complete resection is impossible, and tumors in critical locations like the brainstem may be inoperable. Therefore, the surgical goals are limited to the following five aspects: ① to establish pathological diagnosis, ② to reduce tumor volume and cell count, ③ to improve symptoms and relieve intracranial hypertension, ④ to prolong life and create opportunities for subsequent comprehensive treatment, ⑤ to obtain tumor cell kinetic data to guide effective treatment. Based on growth location and characteristics, approximately 50% cannot be completely resected. To avoid postoperative functional damage, even in complete resections, residual tumors may remain at the primary site, making it difficult to achieve a cure with high recurrence rates. Long-term follow-up and surveys at our hospital show that Grade 3-4 gliomas recur most rapidly within one month, while slower recurrences may take half a year. Grade 1-2 gliomas generally recur within 1-2 years.
Glioma Radiotherapy: Radiotherapy is almost a standard treatment for all glioma types, though efficacy varies. Medulloblastomas are highly sensitive to radiotherapy, while ependymomas are moderately sensitive. Other types show little sensitivity, with some studies suggesting similar prognoses between irradiated and non-irradiated patients. Additionally, radiation-induced necrosis can have significant impacts on brain function. X-knife and gamma-knife are both forms of radiotherapy. Due to tumor location, size (generally limited to less than 3 cm), and radiation sensitivity, their use is limited. Currently, gliomas, especially malignant astrocytomas (Grades III-IV) and glioblastomas, are not considered suitable for knife treatment.
Glioma Chemotherapy: Principally used for malignant tumors, but chemotherapy drugs are limited by the blood-brain barrier and drug toxicity, with uncertain efficacy. Commonly used Western drugs for glioma treatment have effective rates below 30%.
Traditional Chinese Medicine