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.

The desire to eat normally becomes worse over time, leading to weight loss from vomiting. Nausea is seen in almost all cases of astroblastoma, especially in low-grade tumors.

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".

Along with cranial pressure, patients exhibit noticeable lethargy, increasing in severity as the tumor progresses. In the first few months, morning activities are usually unaffected; over time, these effects become more pronounced, especially late at night. Lethargy can disrupt vital signs, depleting energy and desire to perform simple cognitive tasks.

Astrocytomas are a type of cancer of the brain. They originate in a particular kind of glial cells, star-shaped brain cells in the cerebrum called astrocytes. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs. Astrocytomas are the most common glioma and can occur in most parts of the brain and occasionally in the spinal cord. Within the astrocytomas, there are two broad classes recognized in literature, those with:

- Narrow zones of infiltration (mostly noninvasive tumors; e.g., pilocytic astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images

- Diffuse zones of infiltration (e.g., high-grade astrocytoma, anaplastic astrocytoma, glioblastoma), that share various features, including the ability to arise at any location in the CNS (Central Nervous System), but with a preference for the cerebral hemispheres; they occur usually in adults; and an intrinsic tendency to progress to more advanced grades.

People can develop astrocytomas at any age. The low-grade type is more often found in children or young adults, while the high-grade type are more prevalent in adults. Astrocytomas in the base of the brain are more common in young people and account for roughly 75% of neuroepithelial tumors.

There is a wide range of symptoms that patients show. Symptoms can lie dormant, but come about due to Obstructive hydrocephalus. These symptoms include:

- Intracranial pressure

- Headache

- Papilledema

- Vomiting

- Light headedness

- Impaired mental activity

- Gait instability

In rare and extreme cases, more severe symptoms can be observed:

- Memory disturbance

- Dementia

- Hemiparesis

- Seizures

- Hemorrhage

- Psychosis

AT/RT may be related to malignant rhabdoid tumor (MRT), which occurs outside the CNS, usually in the kidney. The finding that AT/RT and MRT both have deletions of the "INI1" gene indicates that rhabdoid tumors of the kidney and brain are at least closely related. AT/RT and MRT also have similar histology and similar clinical and demographic features. Moreover, 10–15% of MRT patients have simultaneous or subsequent brain tumors, many of which are secondary or primary MRT.

A ganglioneuroma is typically asymptomatic, and is typically only discovered when being examined or treated for another condition. Any symptoms will depend upon the tumor's location and the nearby organs affected.

For example, a tumor in the chest area may cause breathing difficulty, chest pain, and trachea compression. If the tumor is located lower in the abdomen, it may cause abdominal pain and bloating. A tumor near the spinal cord may cause spinal deformity or spinal compression, leading to pain and loss of muscle control or sensation in the legs and/or arms.

These tumors may produce certain hormones, which can cause diarrhea, an enlarged clitoris (in females), high blood pressure, increased body hair, and sweating.

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.

Clinical signs and symptoms depend on the location of the tumor.

Since many of the tumors occur in the posterior fossa, they present like other posterior fossa tumors, often with headache, vomiting, lethargy, and ataxia (unsteady gait). A case of a seven-month-old child with a primarily spinal tumor that presented with progressive paraplegia and abnormal feeling in the legs was reported.

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.

Central neurocytoma, abbreviated CNC, is an extremely rare, ordinarily benign intraventricular brain tumour that typically forms from the neuronal cells of the septum pellucidum. The majority of central neurocytomas grow inwards into the ventricular system forming interventricular neurocytomas. This leads to two primary symptoms of CNCs, blurred vision and increased intracranial pressure. Treatment for a central neurocytoma typically involves surgical removal, with an approximate 1 in 5 chance of recurrence. Central neurocytomas are classified as a grade II tumor under the World Health Organization's classification of tumors of the nervous system.

Ganglioneuroma is a rare and benign tumor of the autonomic nerve fibers arising from neural crest sympathogonia, which are completely undifferentiated cells of the sympathetic nervous system. However, ganglioneuromas themselves are fully differentiated neuronal tumors that do "not" contain immature elements.

Ganglioneuromas most frequently occur in the abdomen, however these tumors can grow anywhere sympathetic nervous tissue is found. Other common locations include the adrenal gland, paraspinal retroperitoneum, posterior mediastinum, head, and neck.

The first symptoms of neuroblastoma are often vague making diagnosis difficult. Fatigue, loss of appetite, fever, and joint pain are common. Symptoms depend on primary tumor locations and metastases if present:

- In the abdomen, a tumor may cause a swollen belly and constipation.

- A tumor in the chest may cause breathing problems.

- A tumor pressing on the spinal cord may cause weakness and thus an inability to stand, crawl, or walk.

- Bone lesions in the legs and hips may cause pain and limping.

- A tumor in the bones around the eyes or orbits may cause distinct bruising and swelling.

- Infiltration of the bone marrow may cause pallor from anemia.

Neuroblastoma often spreads to other parts of the body before any symptoms are apparent and 50 to 60% of all neuroblastoma cases present with metastases.

The most common location for neuroblastoma to originate (i.e., the primary tumor) is in the adrenal glands. This occurs in 40% of localized tumors and in 60% of cases of widespread disease. Neuroblastoma can also develop anywhere along the sympathetic nervous system chain from the neck to the pelvis. Frequencies in different locations include: neck (1%), chest (19%), abdomen (30% non-adrenal), or pelvis (1%). In rare cases, no primary tumor can be discerned.

Rare but characteristic presentations include transverse myelopathy (tumor spinal cord compression, 5% of cases), treatment-resistant diarrhea (tumor vasoactive intestinal peptide secretion, 4% of cases), Horner's syndrome (cervical tumor, 2.4% of cases), opsoclonus myoclonus syndrome and ataxia (suspected paraneoplastic cause, 1.3% of cases), and hypertension (catecholamine secretion or renal artery compression, 1.3% of cases).

Common symptoms include seizure, headaches, nausea and vomiting, memory loss, changes to personality, mood or concentration; and localized neurological problems.

The kind of symptoms produced depends more on the location of the tumor than on its pathological properties. The tumor can start producing symptoms quickly, but occasionally is an asymptomatic condition until it reaches an enormous size.

Symptoms may include:

- Swelling in the extremities (arms or legs), also called peripheral edema; the swelling often is painless.

- Difficulty in moving the extremity that has the tumor, including a limp.

- Soreness localized to the area of the tumor or in the extremity.

- Neurological symptoms.

- Pain or discomfort: numbness, burning, or "pins and needles."

- Dizzyness and/or loss of balance.

Primitive neuroectodermal tumor (PNET) is a malignant (cancerous) neural crest tumor. It is a rare tumor, usually occurring in children and young adults under 25 years of age. The overall 5 year survival rate is about 53%.

It gets its name because the majority of the cells in the tumor are derived from neuroectoderm, but have not developed and differentiated in the way a normal neuron would, and so the cells appear "primitive".

PNET belongs to the Ewing family of tumors.

An X-ray computed tomography (CT) or magnetic resonance imaging (MRI) scan is necessary to characterize the extent of these tumors (size, location, consistency). CT will usually show distortion of third and lateral ventricles with displacement of anterior and middle cerebral arteries. Histologic analysis is necessary for grading diagnosis.

In the first stage of diagnosis the doctor will take a history of symptoms and perform a basic neurological exam, including an eye exam and tests of vision, balance, coordination and mental status. The doctor will then require a computerized tomography (CT) scan and magnetic resonance imaging (MRI) of the patient's brain. During a CT scan, x rays of the patient's brain are taken from many different directions. These are then combined by a computer, producing a cross-sectional image of the brain. For an MRI, the patient relaxes in a tunnel-like instrument while the brain is subjected to changes of magnetic field. An image is produced based on the behavior of the brain's water molecules in response to the magnetic fields. A special dye may be injected into a vein before these scans to provide contrast and make tumors easier to identify.

If a tumor is found, it will be necessary for a neurosurgeon to perform a biopsy on it. This simply involves the removal of a small amount of tumor tissue, which is then sent to a neuropathologist for examination and grading. The biopsy may take place before surgical removal of the tumor or the sample may be taken during surgery. Grading of the tumor sample is a method of classification that helps the doctor to determine the severity of the astrocytoma and to decide on the best treatment options. The neuropathologist grades the tumor by looking for atypical cells, the growth of new blood vessels, and for indicators of cell division called mitotic figures.

It is classified into two types, based on location in the body: peripheral PNET and CNS PNET.

Malignant peripheral nerve sheath tumors are a rare type of cancer that arise from the soft tissue that surrounds nerves. They are a type of sarcoma. Most malignant peripheral nerve sheath tumors arise from the nerve plexuses that distribute nerves into the limbs—the brachial and lumbar plexuses—or from nerves as they arise from the trunk.

Malignant triton tumor (MTT) is a relatively rare, aggressive tumor made up of both malignant schwannoma cells and malignant rhabdomyoblasts. It's classified as a malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation.

The unusual name "triton" was first used in reference to observation of supernumerary limbs containing bone and muscle growing on the backs of triton salamanders after the implantation of sciatic nerve tissue.

There are three diagnostic criteria proposed:

1. the tumor arises along a peripheral nerve, or in a ganglioneuroma, or in a patient with neurofibromatosis type 1 (NF1), or has a metastatic character

2. the growth characteristics of the tumor is typical for a Schwann cell tumor

3. rhabdomyoblasts arise within the body of the tumor.

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive cancer that begins within the brain. Initially, signs and symptoms of glioblastoma are non-specific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Worsening of symptoms often is rapid. This may progress to unconsciousness.

The cause of most cases is unclear. Uncommon risk factors include genetic disorders such as neurofibromatosis and Li–Fraumeni syndrome, and previous radiation therapy. Glioblastomas represent 15% of brain tumors. They can either start from normal brain cells or develop from an existing low-grade astrocytoma. The diagnosis typically is made by a combination of CT scan, MRI scan, and tissue biopsy.

There is no clear way to prevent the disease. Typically, treatment involves surgery, after which chemotherapy and radiation therapy are used. The medication temozolomide is used frequently as part of chemotherapy. High dose steroids may be used to help reduce swelling and decrease symptoms. It is unclear whether trying to remove all or simply most of the cancer is better.

Despite maximum treatment, the cancer usually recurs. The most common length of survival following diagnosis is 12 to 15 months, with fewer than 3% to 5% of people surviving longer than five years. Without treatment, survival is typically three months. It is the most common cancer that begins within the brain and the second most common brain tumor, after meningioma. About 3 per 100,000 people develop the disease a year. It most often begins around 64 years of age and occurs more commonly in males than females. Immunotherapy is being studied in glioblastoma with promising results.

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.

Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands, but can also develop in the neck, chest, abdomen, or spine. Symptoms may include bone pain, a lump in the abdomen, neck, or chest, or a painless bluish lump under the skin.

Occasionally neuroblastoma may be due to a mutation inherited from a person's parents. Environmental factors have not been found to be involved. Diagnosis is based on a tissue biopsy. Occasionally it may be found in a baby by ultrasound during pregnancy. At diagnosis the cancer has usually already spread. The cancer is divided into low, intermediate, and high risk groups based on a child's age, cancer stage, and what the cancer looks like.

Treatment and outcomes depends on the risk group a person is in. Treatments may include observation, surgery, radiation, chemotherapy, or stem cell transplantation. Low-risk disease in babies typically has a good outcome with surgery or simply observation. In high-risk disease chances of long term survival, however, are less than 40% despite aggressive treatment.

Neuroblastoma is the most common cancer in babies and the third most common cancer in children after leukemia and brain cancer. About 1 in every 7,000 children is affected at some point in time. About 90% of cases occur in children less than 5 years old and it is rare in adults. Of cancer deaths in children about 15% are due to neuroblastoma. The disease was first described in the 1800s.