Introduction
The brain is one of the vital organs in our body that controls almost all body functions. When a cyst or tumor develops, it can have greater implications for our body and is known by the name brain tumor. Ganglioglioma is a rare form of benign brain tumor marked by seizures. It can be tackled with prompt treatment.
What Is Ganglioglioma?
Ganglioglioma is a specific type of tumor that develops anywhere in the brain. It is a rare condition that comes under the category of mixed neuronal-glial tumors. They are generally low-grade and relatively slow growing in nature, but at times they may showcase features of a high-grade lesion. They involve both neural and glial components. Certain studies concluded that the condition has a slight gender predilection towards the male population. One of the major concerns is that it develops mostly in younger age groups within the age of 20 years, with special emphasis on infants and children.
Which Part of the Brain Is Most Affected by Ganglioglioma?
Our brain grossly comprises the cerebellum, cerebrum, brain stem, and spinal cord. The cerebral cortex, in turn, consists of four different lobes on either side - frontal, temporal, occipital, and parietal lobes. Though ganglioglioma can develop all over the brain, the temporal lobe is the most common site of occurrence, followed by the frontal and parietal lobes. The incidence of ganglioglioma in the temporal lobe is almost 85 %. Sometimes tumors develop in deeper vital parts of the brain like the brain stem and cerebellum.
What Are the Symptoms of Ganglioglioma?
The hallmark symptom of ganglioglioma is seizure (epilepsy). Epilepsy associated with ganglioglioma generally does not respond much to anti-epileptic medicines. The pattern of epilepsy varies with the site of the tumor. For example, patients with temporal lobe ganglioglioma exhibit characteristic temporal lobe epilepsy and aura. At the same time, psychomotor seizures, generalized seizures, and tonic-clonic seizures are reported in tumors involving other brain parts. In addition, as the tumor cells grow, it increases pressure within the brain (intracranial), leading to other associated symptoms like headache, tiredness, nausea, vomiting, neurological issues, and hemiparesis (one-sided weakness of the body). Headache, nausea, and vomiting are reported, especially in the morning when the patient wakes up from bed.
Is There Any Risk Factor for the Development of Ganglioglioma?
In certain cases, ganglioglioma lesions are seen in association with certain genetic syndromes - neurofibromatosis I and tuberous sclerosis. In addition, it is often associated with certain mutations like BRAF V600E, but there is no conclusive evidence for its association.
How Can We Diagnose Ganglioglioma?
Diagnosis requires a thorough medical history, certain neurological tests, and complex diagnostic procedures. Neurological tests look for neurological issues like loss of reflexes, coordination, and muscle weakness. Other diagnostic procedures include computed tomography (CT scan), positron emission tomography (PET scan), magnetic resonance imaging (MRI), electroencephalogram (EEG), magnetic resonance spectroscopy (MRS), and biopsy.
Computed tomography gives a clear picture of the mass. It also helps to identify calcification and bone thinning in response to the growth of the tumor. In addition, EEG helps to assess the electrical process going through the brain. Imaging techniques reflect the nature of the lesion, either solid or cystic, and throw light on the diagnosis process. Finally, a biopsy reveals the exact nature of the tumor cells. All these diagnostic tests not only help in the diagnosis but also facilitates treatment planning.
What Are the Available Treatment Strategies?
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Surgical resection
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Gamma knife radiotherapy (GKRT)
The keystone for treating ganglioglioma is surgical resection (removing the tumor by surgery). It involves local resection of the affected part with significant normal border cells to ensure zero recurrences. In addition, resection of the ganglioglioma resolves seizures. Gross total resection (GTR) offers a much better prognosis. Unfortunately, local resection is not possible in all cases. For example, if the lesion involves parts of the brain that cannot be completely resected, then complete local resection cannot be achieved, which could sometimes lead to the re-occurrence of the lesion. So partial or subtotal resection should be assisted with appropriate adjuvant therapies like radiotherapy and chemotherapy. Studies have proven that gamma knife radiation therapy is a potent treatment strategy for ganglioglioma in inoperable locations, especially to manage the growth of residual tumor cells left over there.
What Are the Prognostic Factors for Ganglioglioma?
The prognosis for ganglioglioma depends on numerous factors. Some of the crucial factors include- the nature of the tumor, the size and location of the tumor, and the treatment interventions.
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Nature of the Tumor- Most gangliogliomas project a slow growth rate without invasion into adjacent structures or organs. They are categorized under low grades. Very rarely, certain gangliogliomas manifest a faster growth rate with local spread, categorized as high-grade ganglioglioma. Low-grade tumors reflect a better prognosis with prompt treatment when compared with high-grade tumors.
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Location and Size of the Tumor- Ganglioglioma in the temporal lobe of the cerebral cortex demonstrates a favorable prognosis. But when they develop over deeper and more vital areas of the brain like the cerebellum, brain stem, and spinal cord, then the prognosis becomes unfavorable. When a tumor develops in an inoperable location, treatment will become very complex, and in most cases, complete removal would not be possible. In addition, complete removal of the tumor is easier in small-sized tumors rather than larger ones.
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Treatment Intervention- Gangliogliomas completely removed by microsurgery showcase a better prognosis with less chance of recurrence. However, partially removed, gangliogliomas tend to develop residual tumors affecting the prognosis. In addition, the time of treatment intervention also greatly reflects the prognosis. Early diagnosis and early onset of treatment are favorable factors for better prognosis and often pave the way for a complete cure of the condition.
Do Any Other Diseases Resemble That of a Ganglioglioma?
Few other tumors that develop over the cortex and spinal cord show a resemblance to that of a ganglioglioma. Some of them are :
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Dysembryoplastic neuroepithelial tumors (DNET).
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Desmoplastic infantile astrocytoma and ganglioglioma.
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Pleomorphic xanthoastrocytoma (PXA).
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Astrocytoma of the spinal cord.
Conclusion
Ganglioglioma is an uncommon tumor that develops in the brain. Younger age groups are more susceptible to ganglioglioma. However, surgical intervention can properly manage it with a considerable prognosis leading to higher survival rates. So the need of the hour is early diagnosis and prompt treatment.
