There are many possible symptoms of oligodendrogliomas that are similar to other gliomas. These symptoms may include headache, seizure and speech or motor changes.

Children affected by pilocytic astrocytoma can present with different symptoms that might include failure to thrive (lack of appropriate weight gain/ weight loss), headache, nausea, vomiting, irritability, torticollis (tilt neck or wry neck) difficulty to coordinate movements and visual complaints (including nystagmus). The complaints may vary depending on the location and size of the neoplasm. The most common symptoms are associated with increased intracranial pressure due to the size of the neoplasm.

Seizures, frequent mood changes, and headaches are among the earliest symptoms of the tumor. Hemiparesis, or physical weakness on one side of the body, is also common. A continuous EEG recording of the brain's electrical activity may help to identify and localize seizure activity, especially in children. CT scans and MRI scans of the brain may show the presence of a diffuse mass that fails to light up when a contrast dye is given. In some cases, a biopsy may be required to confirm the nature of the tumour.

Initial presenting symptoms most commonly are headache, depressed mental status, focal neurological deficits, and/or seizures. The growth rate and mean interval between onset of symptoms and diagnosis is approximately 1.5–2 years but is highly variable, being intermediate between that of low-grade astrocytomas and glioblastomas. Seizures are less common among patients with anaplastic astrocytomas compared to low-grade lesions.

The most common symptom of the papillary tumor is a headache. Because headaches are so common, most people think nothing of it. This is why brain tumors are so dangerous. There are not a lot of symptoms that go along with them so people tend to wait a long time before seeking medical help. Most of the time people will go see a doctor when their headaches become consistent and start to never go away. This symptom however occurs secondary to hydrocephalus, which is a result from compression of the cerebral aqueduct. The cerebral aqueduct is a narrow channel in the midbrain, which connects the third and fourth ventricles. When a tumor blocks the pathway of the cerebrospinal fluid, this will cause headaches in the patient. Often when hydrocephalus occurs, a shunt is put in place in order to alleviate the pressure. In one case study, an endoscopic third ventriculostomy was performed as a first line procedure to treat the hydrocephalus and also for diagnostic purposes.

In some cases, patients have had progressive diplopia, or double vision. Also, although not in all cases, patients sometimes suffer from nausea and vomiting.

Fibrillary astrocytomas also called low grade or diffuse astrocytomas, are a group of primary slow growing brain tumors. They typically occur in adults between the ages of twenty and fifty.

Individuals with this type of tumor may have no symptoms if cerebrospinal fluid (CSF) flow remains open. Obstruction of CSF flow will result in the symptoms associated with increased CSF pressure: nausea, vomiting, headache (often positional), lethargy, blurry or double vision, new or worsened seizures, and personality change.

Trilateral retinoblastoma (TRb) is a malignant midline primitive neuroectodermal tumor occurring in patients with inherited uni- or bilateral retinoblastoma. In most cases trilateral retinoblastoma presents itself as pineoblastoma (pineal TRb). In about a fourth of the cases the tumor develops in another intracranial region, most commonly supra- or parasellar (non-pineal TRb), but there are reported cases with non-pineal TRb in the 3rd ventricle. In most cases pineal TRb is diagnosed before the age of 5, but after the diagnosis of retinoblastoma. Non-pineal TRb, however, is often diagnosed simultaneous with retinoblastoma. Prognosis of patients with trilateral retinoblastoma is dismal, only a few patients have survived more than 5 years after diagnosis; all survivors were diagnosed with small tumors in a subclinical stage. Recent advances in (high-dose) chemotherapy treatment regimens and early detection have improved survival of patients with trilateral retinoblastoma.

Oligoastrocytomas are a subset of brain tumors that present with an appearance of mixed glial cell origin, astrocytoma and oligodendroglioma. These types of glial cells that become cancerous are involved with insulating and regulating the activity of neuron cells in the central nervous system. Often called a "mixed glioma", about 2.3% of all reported brain tumors are diagnosed as oligoastrocytoma. The median age of diagnosis is 42.5.

Oligoastrocytomas, like astrocytomas and oligodendrogliomas, can be divided into low-grade and anaplastic variant, the latter characterized by high , conspicuous cytologic , mitotic activity and, in some cases, microvascular proliferation and necrosis.

However, lower grades can have less aggressive biology.

These are largely supratentorial tumors of adulthood that favor the frontal and temporal lobes.

Symptoms of gliomas depend on which part of the central nervous system is affected. A brain glioma can cause headaches, vomiting, seizures, and cranial nerve disorders as a result of increased intracranial pressure. A glioma of the optic nerve can cause visual loss. Spinal cord gliomas can cause pain, weakness, or numbness in the extremities. Gliomas do not metastasize by the bloodstream, but they can spread via the cerebrospinal fluid and cause "drop metastases" to the spinal cord.

A child who has a subacute disorder of the central nervous system that produces cranial nerve abnormalities (especially of cranial nerve VII and the lower bulbar nerves), long-tract signs, unsteady gait secondary to spasticity, and some behavioral changes is most likely to have a pontine glioma.

A Rosenthal fiber is a thick, elongated, worm-like or "corkscrew" eosinophilic (pink) bundle that is found on H&E staining of the brain in the presence of long-standing gliosis, occasional tumors, and some metabolic disorders.

Its presence is associated with either pilocytic astrocytoma (more common) or Alexander's disease (a rare leukodystrophy). They are also seen in the context of fucosidosis.

Pilocytic astrocytoma is the most common primitive tumor in pediatric patients.

Pilocytic astrocytoma or juvenile pilocytic astrocytoma or cystic cerebellar astrocytoma (and its variant juvenile pilomyxoid astrocytoma) is a brain tumor that occurs more often in children and young adults (in the first 20 years of life). They usually arise in the cerebellum, near the brainstem, in the hypothalamic region, or the optic chiasm, but they may occur in any area where astrocytes are present, including the cerebral hemispheres and the spinal cord. These tumors are usually slow growing and benign. The neoplasms are associated with the formation of a single (or multiple) cyst(s), and can become very large.

Pilocytic astrocytomas are often cystic, and, if solid, tend to be well-circumscribed. It is characteristically easily seen on Computed tomography (CT scans) and Magnetic Resonance Imaging (MRI).

Juvenile pilocytic astrocytoma is associated with neurofibromatosis type 1 (NF1), and optic gliomas are among the most frequently encountered tumors in patients with this disorder. The majority of pilocytic astrocytomas have a unique KIAA1549-BRAF fusion gene.

Papillary tumors of the pineal region (PTPR) were first described by A. Jouvet et al. in 2003 and were introduced in the World Health Organization (WHO) classification of Central Nervous System (CNS) in 2007. Papillary Tumors of the Pineal Region are located on the pineal gland which is located in the center of the brain. The pineal gland is located on roof of the diencephalon. It is a cone shaped structure dorsal to the midbrain tectum. The tumor appears to be derived from the specialized ependymal cells of the subcommissural organ. Papillary tumors of the central nervous system and particularly of the pineal region are very rare and so diagnosing them is extremely difficult.

Gliomas can be classified according to whether they are above or below a membrane in the brain called the tentorium. The tentorium separates the cerebrum (above) from the cerebellum (below).

- The supratentorial is above the tentorium, in the cerebrum, and mostly found in adults (70%).

- The infratentorial is below the tentorium, in the cerebellum, and mostly found in children (70%).

- The pontine tumors are located in the pons of the brainstem. The brainstem has three parts (pons, midbrain, and medulla); the pons controls critical functions such as breathing, making surgery on these extremely dangerous.

Subependymal giant cell astrocytoma (SEGA, SGCA, or SGCT) is a low-grade astrocytic brain tumor (astrocytoma) that arises within the ventricles of the brain. It is most commonly associated with tuberous sclerosis complex (TSC). Although it is a low-grade tumor, its location can potentially obstruct the ventricles and lead to hydrocephalus.

In anywhere from fifty to eighty percent of cases, the first symptom of an oligodendroglioma is the onset of seizure activity. They occur mainly in the frontal lobe.

Headaches combined with increased intracranial pressure are also a common symptom of oligodendroglioma. Depending on the location of the tumor, any neurological deficit can be induced, from visual loss, motor weakness and cognitive decline. A computed tomography (CT) or magnetic resonance imaging (MRI) scan is necessary to characterize the anatomy of this tumor (size, location, heter/homogeneity). However, final diagnosis of this tumor, like most tumors, relies on histopathologic examination (biopsy examination).

It may affect any part of the brain or even the spinal cord, optic nerve and compact white matter. Clinical manifestations are indefinite, and include headache, seizures, visual disturbances, corticospinal tract deficits, lethargy, and dementia. A case of gliomatosis cerebri presenting as rapidly progressive dementia and Parkinson's disease like symptoms has been described in an 82-year-old woman.

Anaplastic astrocytomas fall under the category of high grade gliomas (WHO grade III-IV), which are pathologically undifferentiated gliomas that carry a poor clinical prognosis. Unlike glioblastomas (WHO grade IV), anaplastic astrocytomas lack vascular proliferation and necrosis on pathologic evaluation. Compared to grade II tumors, anaplastic astrocytomas are more cellular, demonstrate more atypia, and mitoses are seen.

Pineoblastoma (also pinealoblastoma) is a malignant tumor of the pineal gland. A pineoblastoma is a supratentorial midline primitive neuroectodermal tumor.

Pineoblastoma may occur in patients with hereditary uni- or bilateral retinoblastoma. When retinoblastoma patients present with pineoblastoma this is characterized as "trilateral retinoblastoma". Up to 5% of patients with hereditary retinoblastoma are at risk of developing trilateral retinoblastoma. Prognosis of patients with trilateral retinoblastoma is dismal, only a few patients have survived more than 5 years after diagnosis; all survivors were diagnosed with small tumors in a subclinical stage. Recent advances in (high-dose) chemotherapy treatment regimens and early detection have improved survival of patients with trilateral retinoblastoma to up to 50%.

Ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor which most frequently occurs in the temporal lobes of children and young adults.

Gangliogliomas are generally benign WHO grade I tumors; the presence of anaplastic changes in the glial component is considered to represent WHO grade III (anaplastic ganglioglioma). Criteria for WHO grade II have been suggested, but are not established. Malignant transformation of spinal ganglioglioma has been seen in only a select few cases. Poor prognostic factors for adults with gangliogliomas include older age at diagnosis, male sex, and malignant histologic features.

Headaches as a result of raised intracranial pressure can be an early symptom of brain cancer. However, isolated headache without other symptoms is rarer, and other symptoms often occur before headaches become common. Certain warning signs for headache exist which make it more likely to be associated with brain cancer. These are as defined by the American Academy of Neurology: "abnormal neurological examination, headache worsened by Valsalva maneuver, headache causing awakening from sleep, new headache in the older population, progressively worsening headache, atypical headache features, or patients who do not fulfill the strict definition of migraine".

The signs and symptoms of brain tumors are broad. People with brain tumors will experience them no matter if the tumor is benign (not cancerous) or cancerous. Primary and secondary brain tumors present with similar symptoms, depending on the location, size, and rate of growth of the tumor. For example, larger tumors in the frontal lobe can cause changes in the ability to think. However, a smaller tumor in an area such as Wernicke's area (small area responsible for language comprehension) can result in a greater loss of function.

Gliomatosis cerebri (infiltrative diffuse astrocytosis) is a rare primary brain tumor. It is commonly characterized by diffuse infiltration of the brain with neoplastic glial cells that affect various areas of the cerebral lobes. These malignancies consist of infiltrative threads that spread quickly and deeply into the surrounding brain tissue, or into multiple parts of the brain simultaneously, making them very difficult to remove with surgery or treat with radiation. Gliomatosis cerebi behaves like a malignant tumor that is very similar to Glioblastoma.

While gliomatosis cerebri can occur at any age, it is generally found in the third and fourth decades of life.