Astrocytic hamartomas are an abnormal proliferation of the macroglial astrocytic cells of the retinal nerve fiber layer and are considered benign lesions1. They can be located anywhere within the retina, however are often found at the optic nerve head2. Retinal astrocytic hamartomas are associated with a variety of diseases, but may also be singular and idiopathic. The age of onset plays a crucial role in differentiating the lesions and the course of treatment following diagnosis. Visual symptoms can range from being asymptomatic, to mild visual disturbances, to enucleation in the worst cases- which are associated with systemic conditions. The appearance of astrocytic hamartomas are comparable to a variety of other lesions associated …show more content…
Retinal astrocytic hamartomas typically appear in the first or second decade of life5. Their appearance is often white with a calcified appearance4 that can vary in size, with smaller lesions typically being less defined and a translucent white color5. Larger nodules may have more opaque coloring and white nodules in the inner retina; another common description for astrocytic hamartomas that are larger is “white mulberry” appearance5. The age of onset and diseases associated allow prediction of transformation5. Larger lesions with a later onset typically remain stable, especially if the subject is over 25 years old5. It’s expected that if the lesion is recorded at a young age, it may go under small changes and enlarge5. Retinal astrocytic hamartomas can be a congenital or acquired finding. It is a common finding with a systemic diseases such as tuberous sclerosis, retinitis pigmentosa, or neurofibromatosis1. Systemic disorders will typically result in bilateral and multiple astrocytic hamartomas ,whereas idiopathic findings in a normal person will often result in unilateral and single lesions1,4. Tuberous sclerosis is a congenital disorder with common findings of retinal astrocytic hamartomas that are found in 44% to 87% of patients6. It is an autosomal dominant
The primary ones include these types. Gliomas, the most common brain tumor involving the brain tissue. There are different grades and even types of gliomas. But if the tumor grade is higher, it will probably grow faster. Medullblastomas are brain tumors that in young children. Without treatment it will spread rapidly into the spinal fluid and other parts of the brain. But almost or half of the brain tumors found are benign. These types of brain tumors are usually Meningiomas and Neuromas. Meningiomas begin in the tissue membranes. Neuromas are in the nerves mostly in people over
Tumors can be classified into three types: 1) benign 2) pre malignant 3) malignant tumor. Benign tumors are those which are incapable of abrupt expanding and affecting the other healthy brain tissues. Premalignant tumor is a pre cancerous stage, if not treated properly it may lead to cancers. It is often considered as a disease. Malignant tumor grows rapidly with time an ultimately leads to death of patient. Malignant is a medical term describing a sever growth of a disease. The most common primary brain Tumors are gliomas, wherein 70% are in the group of malignant gliomas, glioblastoma multiform (GBM).The GBM is one of the highest malignant human
Gliomas are primary brain tumors, which mean they start in the brain. They are a fairly common type of brain tumor. These types of tumors originate in the glial cells. Glial cells in the brain surround and support neurons. Because Gliomas often intermix with normal brain tissue, they are called intrinsic brain tumors. Gliomas show up in three different types of cells: astrocytes, oligodendrocytes and ependymal cells. Astrocytomas will be produced by an astrocyte, an oligodendroglioma will be produced by an oligodendrocyte and epedymomas will be produced by an ependymal cell. If there is a mixture of these cells, then it is called a mixed
Current investigations indicate that Central neurocytoma could be of astrocytic origin or mixed lineages. Immunohistochemical tests shows multiple positive markers of neural cell that includes synaptophysin, neuron specific enolase, neuronal specific nuclear protein , and neuron specific class III beta tubulin. In addition to dense core vesicles and parallel microtubules are present in pathology. The tumor also shows positive neurofilament (NF) staining but some of the Central Neurocytoma fails to show consistent pathology. Unfortunately, the Immunohistochemical studies are not specific to draw a concrete conclusion to the origin of neurocytoma. Von Deimling et al. investigation indicated that Central neurocytoma shows glial fibrillary acidic protein (GFAP) and Syn, which is related to reactive astrocytes. Other studies were unable to attain the same results. In vitro, the tumor cells tend to become glial cells regardless of the medium of the culture. In vivo, the origin of the cells is not clear. Some researches hypothesize that CN arise from neural stem cells surrounding the ventricle zones. This hypothesize was based on high levels of choline, cholinergic receptors, gamma-aminobutyric acid, and normal or low levels of glutamate and catecholamines. Kim et al also showed the presence of Musashi-1, and the neuroep- ithelial enhancer gene nestin. These results point towards possible genetic properties to
They are considered to be benign, as they do not invade into the surrounding tissue but have well-defined borders. They occur most often in children and teens with a 10-year survival of over 90 %. Unlike these, Grade II Astrocytomas do invade into healthy tissue and often progress to higher-grade tumors. Patiens have a 5-year survival rate of about 50 % (Goodenberger & Jenkins, 2012). Anaplastic Astrocytomas are fast growing, highly aggressive and mostly occur in young adults. These grade III tumors show a high proliferation rate, mitotic activity and pleomorphism (Kleihues et al., 2002). Most patients progress to grade IV astrocytoma (Ohgaki & Kleihues, 2007). Despite treatment, the 5-year relative survival rate is approximately 29 %. The survival rates vary widely by age with younger people having a better outlook. However, prognoses are much worse for patients diagnosed with glioblastoma. Most patients die within one year from diagnosis (Ostrom et al.,
Only 200-300 cases exist yearly in the United States. Retinoblastoma occurs in children, averages at about 18 months of age, and is given through heredity, so the only two known known risk factors are age and inheritance. Since retinoblastoma has to do with genes, there is no way to fully prevent it. There are ways to avoid passing it down to the children of the patient, such as consulting gene specialists. They can figure out the chances of the child receiving the cancer and can go over their options. There is a procedure called an embryo implant which ensures that the child won't get the cancer, because the developed eye is replaced with the unaffected
The specific cause of Anaplastic Astrocytomas is unknown. However, researchers believe that genetic and immunologic abnormalities, environmental factors (e.g., exposure to ultraviolet rays, certain chemicals, and ionizing radiation), diet, stress, and/or other factors may play contributing roles in causing specific types of cancer. Astrocytomas are more common amongst individuals that have these genetic disease: tuberosis sclerosis, neurofibromatosis, & Li-Fraumeni syndrome. In the case of these rare genetic disease the brain tumor is not passed to the child (Cheong,
Retinoblastoma results when something goes wrong with eye development in the womb or early in life. Instead of developing into specialized eye cells (retinoblasts), the cells grow out of control and form a tumor (retinoblastoma). Retinoblastoma may occur in one or both eyes. It is usually diagnosed before age 3.
A brain tumor is an irregular growth of tissue in the brain or central spine that can disturb proper brain function. There are two types of brain tumors that can either be considered malignant (cancerous), or benign (noncancerous). Doctors denote a tumor according to where in the body the tumor originated. Tumors that are designated as benign are noncancerous because they are the least aggressive type. They begin from cells surrounding the brain, however, they are not comprised of cancerous cells. A malignant tumor is the most life-threatening tumor, as the cancer cells do not have clear borders; thus, they grow rapidly without a clear sign of where it is in proximity to the brain tissue. Furthermore, the other well-known brain tumors are primary
Retinitis Pigmentosa (RP), also known as rod cone dystrophy, is a rare genetic disease that affects the retinas in the eyes. In the United States, it affects 1 in 4,000 people making it the most common inherited retina disease (Nash, et al., 2015). This disease usually leads to blindness because of the deterioration of the light-sensing cells in the retina. Within the retina, there are cells called rods and cones. For people who have RP, the rods, which are responsible for night and peripheral vision, are the cells that deteriorate first. After the rods are affected, the cones follow. Cones are responsible for color perception and central vision. Usually, symptoms of retinitis pigmentosa show up during childhood. At this stage in life, children affected with this disease have a loss of night vision. As these children become adults, the disease causes their eyes develop blind spots in their peripheral vision and eventually these blind spots will merge and create tunnel vision (Nash, et al., 2015). Over time, the disease will affect central vision. Central vision
Brain Tumors- Most common cancer in childhood and occur in 25% of all childhood cancers. Neoplasms can come from any cell, which means tumors can form in all different areas of the brain. Tumors can be benign or malignant. Clinical manifestations of brain tumors are directed towards the affected area. Most common symptom is a headache and vomiting. Neurological changes, behavioral changes, cranial nerve neuropathy and vital sign disturbances may occur depending on the location of the brain tumor. Diagnosis is based on the symptoms the patient presents with. CT and MRI are most commonly used. Tissue specimens are collected and tested. Results help with the diagnosis. Treatments include surgery, chemotherapy and radiotherapy. Not all have to
Retinitis pigmentosa(RP) is an inherited, degenerative eye disease that causes severe vision impairment due to the progressive degeneration of the rod photoreceptor cells in the retina . Retinitis pigmentosa is one of the most common inherited diseases of the retina, affecting 1.5 million people worldwide. Up to 150 mutations are known to cause retinitis pigmentosa, which includes three genetic inheritance patterns- autosomal dominant inheritance, autosomal recessive inheritance, or X-linked inheritance. Symptoms often first appear in childhood that patients would endure nyctalopia, the decreasing vision at night or in low light, then lost of peripheral vision causing “tunnel vision” and finally,
The three most common malignant pediatric tumors include retinoblastoma, gliablastoma, and medulloblastoma (Wechsler-Reya & Scott, 2001). Medulloblastoma is a rapidly growing tumor found in the cerebellum; the part of the brain responsible for posture, balance, and complex motor functions such as swallowing and speech (American Brain Tumor Association [ABTA], 2014). There are five different types of medulloblastoma; classic, large-cell, desmoplastic nodular, melanotic, and medullomyoblastoma. The tissue patterns of the tumor help categorize each type of medulloblastoma. There are about 400 new cases of medullobastomas each year in the US, with the majority being diagnosed in children (ABTA, 2014). Medulloblastomas are found slightly more in males compared to females, and is not common in adults but can occur. Medulloblastoma is the most common brain tumor in children age four and younger, and second most common in children ages 5-14. The median age of diagnosis for this brain tumor is seven and approximately 70% of pediatric medulloblastomas are diagnosed in children under the age of ten (ABTA, 2014). Treatment for most medulloblastomas include surgical removal, chemotherapy and radiation (Wechsler-Reya & Scott, 2001).
Pituitary adenomas have mass effects that include headaches, hypopituitarism and visual defects. Therefore visual field testing is usually associated with a pituitary adenoma in order to see if the tumor is disrupting the optic chiasm. If the optic chiasm is disrupted then an individual will have a reduction in their visual field.
The optic nerve is the second cranial nerve (CN II) in the eye which is tasked to transfer visual information in the form of electrical impulses from the retina to the brain for interpretation. Typically, a human optic nerve is around 0.3-0.4mm in diameter and is protected by a nerve sheath, is surrounded by cerebrospinal fluid (CSF). Visual acuity and contrast sensitivity are two highly important functions that the optic nerve specialises in, and as a result, are the common issues affected by ON. Damage to the optic nerve inhibits proper functioning at the optic chiasm which, depending on the damage, causes specific problems depending on the extent of damage. Patients with MS are often revealed to develop ON as their first symptom. MS is a common central nervous system (CNS) disease that develops through issues relating to inflammatory demyelinating white matter lesions. There have been suggestions that the onset of ON is immune-mediated; activated T cells release cytokines as well as other inflammatory mediators when migrating across the blood-brain barrier and essentially degrade the axons around the optic nerve causing cell death, and thus leading to impaired visual functioning.