The majority of patients can be expected to be cured of their disease and become long-term survivors of central neurocytoma. As with any other type of tumor, there is a chance for recurrence. The chance of recurrence is approximately 20%. Some factors that predict tumor recurrence and death due to progressive states of disease are high proliferative indices, early disease recurrence, and disseminated disease with or without the spread of disease through the cerebral spinal fluid. Long-term follow up examinations are essential for the evaluation of the outcomes that each treatment brings about. It is also essential to identify possible recurrence of CN. It is recommended that a cranial MRI is performed between every 6–12 months.

The histopathologic grading of oligodendrogliomas is controversial. Currently the most commonly used grading schema is based on year 2007 World Health Organization (WHO) guidelines. An updated classification is in progress. Oligodendrogliomas are generally dichotomized into grade II (low grade) and grade III (high grade) tumors. The designation of grade III oligodendroglioma (high grade) generally subsumes the previous diagnoses of anaplastic or malignant oligodendroglioma.

Unfortunately, the WHO guidelines include subjective criteria in differentiating grade II and grade III tumors including the appreciation of "significant" hypercellularity and pleomorphism in the higher grade lesion. In addition, the presence of low mitotic activity, vascular proliferation and necrosis, including pseudopallisading necrosis are insufficient by themselves to elevate the grade of these tumors. This leads to inevitable interobserver variability in diagnosis by pathologists. The ultimate responsibility for making treatment decisions and interpretation of these diagnoses lies with the oncologist in consultation with the patient and their family.

It has been proposed that WHO guidelines should contain a category for grade IV oligodendrogliomas which essentially appear to be glial neoplasms with overwhelming features of glioblastoma multiforme (GBM) arising from known lower grade oligodendrogliomas or GBM with a significant proportion of oligodendroglial differentiation. The diagnostic utility of this latter category is uncertain as these tumors may behave either like glioblastoma or grade III oligodendrogliomas. As such, this is an exceptionally unusual diagnosis.

The updated WHO guidelines published in 2007 recommends classifying such tumors for the time being as 'glioblastoma with oligodendroglioma component'. It remains to be established whether or not these tumors carry a better prognosis than standard glioblastomas.

Surgical excision of the central neurocytoma is the primary consensus among practicing physicians. The surgeons perform a craniotomy to remove the tumor. The ability to remove the tumor and to what extent it is removed is dependent upon the location of the tumor and surgeon experience and preference. The extent of the disease plays a large part in determining how effective the surgery will be. The main goal of a complete surgical resection, of the tumor, can also be hindered by the adherence of the tumor to adjoining structures or hemorrhages. If there is a recurrence of the central neurocytoma, surgery is again the most notable treatment.

The primary diagnosis is made with a computed tomography scan (CT scan). On a scan, hemangioblastoma shows as a well-defined, low attenuation region in the posterior fossa with an enhancing nodule on the wall. Sometimes multiple lesions are present.

Medical imaging plays a central role in the diagnosis of brain tumors. Early imaging methods – invasive and sometimes dangerous – such as pneumoencephalography and cerebral angiography have been abandoned in favor of non-invasive, high-resolution techniques, especially magnetic resonance imaging (MRI) and computed tomography (CT) scans. Neoplasms will often show as differently colored masses (also referred to as processes) in CT or MRI results.

- Benign brain tumors often show up as hypodense (darker than brain tissue) mass lesions on CT scans. On MRI, they appear either hypodense or isointense (same intensity as brain tissue) on T1-weighted scans, or hyperintense (brighter than brain tissue) on T2-weighted MRI, although the appearance is variable.

- Contrast agent uptake, sometimes in characteristic patterns, can be demonstrated on either CT or MRI scans in most malignant primary and metastatic brain tumors.

- Pressure areas where the brain tissue has been compressed by a tumor also appear hyperintense on T2-weighted scans and might indicate the presence a diffuse neoplasm due to an unclear outline. Swelling around the tumor known as "peritumoral edema" can also show a similar result.

This is because these tumors disrupt the normal functioning of the BBB and lead to an increase in its permeability. However, it is not possible to diagnose high- versus low-grade gliomas based on enhancement pattern alone.

The definitive diagnosis of brain tumor can only be confirmed by histological examination of tumor tissue samples obtained either by means of brain biopsy or open surgery. The histological examination is essential for determining the appropriate treatment and the correct prognosis. This examination, performed by a pathologist, typically has three stages: interoperative examination of fresh tissue, preliminary microscopic examination of prepared tissues, and follow-up examination of prepared tissues after immunohistochemical staining or genetic analysis.

The outcome for hemangioblastoma is very good, if surgical extraction of the tumor can be achieved; excision is possible in most cases and permanent neurologic deficit is uncommon and can be avoided altogether if the tumor is diagnosed and treated early. Persons with VHL syndrome have a bleaker prognosis than those who have sporadic tumors since those with VHL syndrome usually have more than one lesion.

Oligodendrogliomas cannot currently be differentiated from other brain lesions solely by their clinical or radiographic appearance. As such, a brain biopsy is the only method of definitive diagnosis. Oligodendrogliomas recapitulate the appearance of the normal resident oligodendroglia of the brain. (Their name derives from the Greek roots 'oligo' meaning " few" and 'dendro' meaning "trees".) They are generally composed of cells with small to slightly enlarged round nuclei with dark, compact nuclei and a small amount of eosinophilic cytoplasm. They are often referred to as "fried egg" cells due to their histologic appearance. They appear as a monotonous population of mildly enlarged round cells infiltrating normal brain parenchyma and producing vague nodules. Although the tumor may appear to be vaguely circumscribed, it is by definition a diffusely infiltrating tumor.

Classically they tend to have a vasculature of finely branching capillaries that may take on a "chicken wire" appearance. When invading grey matter structures such as cortex, the neoplastic oligodendrocytes tend to cluster around neurons exhibiting a phenomenon referred to as "perineuronal satellitosis". Oligodendrogliomas may invade preferentially around vessels or under the pial surface of the brain.

Oligodendrogliomas must be differentiated from the more common astrocytoma. Non-classical variants and combined tumors of both oligodendroglioma and astrocytoma differentiation are seen, making this distinction controversial between different neuropathology groups. In the US, in general, neuropathologists trained on the West Coast are more liberal in the diagnosis of oligodendrogliomas than either East Coast or Midwest trained neuropathologists who render the diagnosis of oligodendroglioma for only classic variants. Molecular diagnostics may make this differentiation obsolete in the future.

Other glial and glioneuronal tumors with which they are often confused due to their monotonous round cell appearance include pilocytic astrocytoma, central neurocytoma, the so-called dysembryoplastic neuroepithelial tumor, or occasionally ependymoma.

Anaplastic astrocytoma, Astrocytoma, Central neurocytoma, Choroid plexus carcinoma, Choroid plexus papilloma, Choroid plexus tumor, Dysembryoplastic neuroepithelial tumour, Ependymal tumor, Fibrillary astrocytoma, Giant-cell glioblastoma, Glioblastoma multiforme, Gliomatosis cerebri, Gliosarcoma, Hemangiopericytoma, Medulloblastoma, Medulloepithelioma, Meningeal carcinomatosis, Neuroblastoma, Neurocytoma, Oligoastrocytoma, Oligodendroglioma, Optic nerve sheath meningioma, Pediatric ependymoma, Pilocytic astrocytoma, Pinealoblastoma, Pineocytoma, Pleomorphic anaplastic neuroblastoma, Pleomorphic xanthoastrocytoma, Primary central nervous system lymphoma, Sphenoid wing meningioma, Subependymal giant cell astrocytoma, Subependymoma, Trilateral retinoblastoma.

If a patient displays congenital melanocytic nevi or giant congenital melanocytic nevi, the criteria for diagnosis of neurocutaneous melanosis is as follows:

- Melanocytic deposits exist within the central nervous system that are either malignant or benign

- The cutaneous lesions, giant or otherwise, are not malignant

This criteria is typically validated through biopsy of the cutaneous lesions and imaging of the central nervous system. It is important to establish that the cutaneous lesions are benign. If not, then the melanocytic deposits in the central nervous system may be the result of metastasis of cutaneous melanoma and not neurocutaneous melanosis.

Imaging has been shown to be the only reliable detection method for the presence of neurocutaneous melanosis that can be performed in living patients. Currently, the preferred imaging modality for diagnosis of neurocutaneous melanosis is Magnetic Resonance Imaging, although ultrasound is another viable option. The signal due melanin deposits in the leptomeninges typical of neurocutaneous melanosis can be easily detected in MRI scans of patients under four months old. In patients above this age, there is some suggestion that normal brain myelination may partially obscure these signals.

As most patients with neurocutaneous melanosis are asymptomatic, those who are diagnosed through MR imaging are not guarantied to develop symptoms. Those diagnosed who did not develop symptoms ranged from 10% to 68%. This wide range is most likely due to the large number of asymptomatic, undiagnosed patients with neurocutaneous melanosis.

The majority of patients with neurocutaneous melanosis are asymptomatic and therefore have a good prognosis with few complications. Most are not diagnosed, so definitive data in not available. For symptomatic patients, the prognosis is far worse. In patients without the presence of melanoma, more than 50% die within 3 years of displaying symptoms. While those with malignancy have a mortality rate of 77% with most patients displaying symptoms before the age of 2.

The presence of a Dandy-Walker malformation along with neurocutaneous melanosis, as occurs in 10% of symptomatic patients, further deteriorates prognosis. The median survival time for these patients is 6.5 months after becoming symptomatic.

Neurocytoma (or neuroepithelioma) is a type of nervous system tumor which is primarily derived from nervous tissue. This is in contrast to the gliomas (such as oligodendroglioma), which are derived from glial cells, and not from nervous tissue.

A neuroectodermal tumor is a tumor of the central or peripheral nervous system.

The diagnostic process typically begins with a medical history workup followed by a medical examination by a physician. Imaging tests, such as CT scans and MRIs, help provide a clearer picture. The physician typically looks for fluid (or other bodily substance) filled sacs to appear in the scans, as is shown in the CT scan of a colloid cyst. A primary health care provider will refer an individual to a neurologist or neurosurgeon for further examination. Other diagnostic methods include radiological examinations and macroscopic examinations. After a diagnosis has been made, immunohistochemistry may be used to differentiate between epithelial cysts and arachnoid cysts. These examinations are useful to get a general idea of possible treatment options, but can be unsatisfactory to diagnose CNS cysts. Professionals still do not fully understand how cysts form; however, analyzing the walls of different cyst types, using electron microscopes and light microscopes, has proven to be the best diagnostic tool. This has led to more accurate cyst classification and correct course of action for treatments that are cyst specific. In the past, before imaging scans or tests were available, medical professionals could only diagnose cysts via exploratory surgery.

The treatment for CGCG is thorough curettage. A referral is made to an oral surgeon. Recurrence ranges from 15%–20%. In aggressive tumors, three alternatives to surgery are undergoing investigation:

- corticosteroids;

- calcitonin (salmon calcitonin);

- interferon α-2a.

These therapeutic approaches provide positive possible alternatives for large lesions. The long term prognosis of giant-cell granulomas is good and metastases do not develop.

Most optic nerve tumors (65 percent) are gliomas that occur somewhere along the anterior visual pathway.

An optic nerve melanocytoma is a tumor made up of melanocytes and melanin. These tumors are typically a benign; they can grow, but rarely transform into a malignancy. Even so, local growth can affect adjacent tissues.

Focal nodular hyperplasia (FNH) is a benign tumor of the liver (hepatic tumor), which is the second most prevalent tumor of the liver (the first is hepatic hemangioma). It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour was once often resected because it was difficult to distinguish from hepatic adenoma, but with modern multiphase imaging is usually now diagnosed by strict imaging criteria and not resected.

A neurosurgeon may open a portion of the body and insert a shunt into cerebral spinal fluid (CSF) filled cysts to allow drainage into CSF pathways. The fluid from the cyst is then drained into the abdomen, the body reabsorbs the fluid (reabsorption of fluid does not cause any harm). This type of surgical treatment is often performed to relieve pressure on the brain from a cyst within the cerebral cortex.

FNH is not a true neoplasm; it is believed to result from localized hyperplastic hepatocyte response to an underlying congenital arteriovenous malformation. It consists of normal liver constituents in an abnormally organized pattern, grows in a stellate pattern and may display central necrosis when large. Additionally evidence suggests that the incidence of FNH is related to oral contraceptive use.

The histology of CGCG is one that is composed of many multinucleated giant cells. There is evidence that these giant cells represent osteoclasts (bone-eating cells); others suggest they are more like macrophages. The giant cells may be diffusely located throughout the lesion or focally aggregate in the lesion. The giant cells are typically either large and round, or small and irregular, and can vary greatly in size and shape. Close examination may reveal some hemosiderin deposits as well.

Dermatofibromas are hard solitary slow-growing papules (rounded bumps) that may appear in a variety of colours, usually brownish to tan; they are often elevated or pedunculated. A dermatofibroma is associated with the dimple sign; by applying lateral pressure, there is a central depression of the dermatofibroma. Although typical dermatofibromas cause little or no discomfort, itching and tenderness can occur. Dermatofibromas can be found anywhere on the body, but most often they are found on the legs and arms. They occur most often in women; the male to female ratio is about 1:4. The age group in which they most commonly occur is 20 to 45 years.

Some physicians and researchers believe dermatofibromas form as a reaction to previous injuries such as insect bites or thorn pricks. They are composed of disordered collagen laid down by fibroblasts. Dermatofibromas are classed as benign skin lesions, meaning they are completely harmless, though they may be confused with a variety of subcutaneous tumours. Deep penetrating dermatofibromas may be difficult to distinguish, even histologically, from rare malignant fibrohistocytic tumours like dermatofibrosarcoma protuberans.

Dermatofibromas typically have a positive "buttonhole sign", or central dimpling in the center.

Research shows that children with cancer are at risk for developing various cognitive or learning problems. These difficulties may be related to brain injury stemming from the cancer itself, such as a brain tumor or central nervous system metastasis or from side effects of cancer treatments such as chemotherapy and radiation therapy. Studies have shown that chemo and radiation therapies may damage brain white matter and disrupt brain activity.

Cognitive problems that have been associated with cancer and its treatments in children include deficits in attention, working memory, processing speed, mental flexibility, persistence, verbal fluency, memory, motor skills, academic achievement and social function. These deficits have been shown to occur irrespective of age, socioeconomic status, months since onset or cessation of treatment, anxiety, fatigue and dosage schedule.

Benign fibrous histiocytomas (also known as dermal dendrocytoma, dermatofibroma, fibrous dermatofibroma, fibrous histiocytoma, fibroma simplex, nodular subepidermal fibrosis, and sclerosing hemangioma) are benign skin growths.

Currently there are no official tests or treatments for ROHHAD. Each child has the symptoms above at different ages, yet most symptoms are eventually present. Many children are misdiagnosed or are never diagnosed until alveolar hypoventilation occurs.

Certain treatments for childhood cancer are known to cause learning problems in survivors, particularly when central nervous system (CNS)-directed therapies are used (e.g. radiation; high-dose methotrexate or cytarabine; or intrathecal chemotherapy). As the mortality rates of childhood cancers have plummeted since effective treatment regiments have been introduced, greater attention has been paid to the effect of treatment on neurocognitive morbidity and quality of life of survivors. The goal of treatment for childhood cancers today is to minimize these adverse "late effects", while ensuring long-term survival.