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Orbital Tumor
Eye neoplasms can affect all parts of the eye, and can be a benign tumor or a malignant tumor (cancer). Eye cancers can be primary (starts within the eye) or metastatic cancer (spread to the eye from another organ). The two most common cancers that spread to the eye from another organ are breast cancer and lung cancer. Other less common sites of origin include the prostate, kidney, thyroid, skin, colon and blood or bone marrow. Types Tumors in the eye and orbit can be benign like dermoid cysts, or malignant like rhabdomyosarcoma and retinoblastoma. Malignant The most common eyelid tumor is called basal cell carcinoma. This tumor can grow around the eye but rarely spreads to other parts of the body. Other types of common eyelid cancers include squamous carcinoma, sebaceous carcinoma and malignant melanoma. The most common orbital malignancy is ''orbital lymphoma''. This tumor can be diagnosed by biopsy with histopathologic and immunohistochemical analysis. Most patients with or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncology
Oncology is a branch of medicine that deals with the study, treatment, diagnosis and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's etymological origin is the Greek word ὄγκος (''ónkos''), meaning "tumor", "volume" or "mass". Oncology is concerned with: * The diagnosis of any cancer in a person (pathology) * Therapy (e.g. surgery, chemotherapy, radiotherapy and other modalities) * Follow-up of cancer patients after successful treatment * Palliative care of patients with terminal malignancies * Ethical questions surrounding cancer care * Screening efforts: ** of populations, or ** of the relatives of patients (in types of cancer that are thought to have a hereditary basis, such as breast cancer) Diagnosis Medical histories remain an important screening tool: the character of the complaints and nonspecific symptoms (such as fatigue, weight loss, unexplained anemia, fever of unknown origin, paraneoplastic phenome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Cell Carcinoma
Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer. It often appears as a painless raised area of skin, which may be shiny with small blood vessels running over it. It may also present as a raised area with ulceration. Basal-cell cancer grows slowly and can damage the tissue around it, but it is unlikely to spread to distant areas or result in death. Risk factors include exposure to ultraviolet light, having lighter skin, radiation therapy, long-term exposure to arsenic and poor immune-system function. Exposure to UV light during childhood is particularly harmful. Tanning beds have become another common source of ultraviolet radiation. Diagnosis often depends on skin examination, confirmed by tissue biopsy. It remains unclear whether sunscreen affects the risk of basal-cell cancer. Treatment is typically by surgical removal. This can be by simple excision if the cancer is small; otherwise, Mohs surgery is generally recomme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraocular Lymphoma
Intraocular lymphoma is a rare malignant form of eye cancer. Intraocular lymphoma may affect the eye secondarily from a metastasis from a non-ocular tumor or may arise within the eye primarily (primary intraocular lymphoma, PIOL). PIOL is a subset of primary central nervous system lymphoma (PCNSL). PCNSL (and PIOL) are most commonly a diffuse large B-cell immunohistologic subtype of non-Hodgkin's lymphoma according to the World Health Organization (WHO) classification of lymphomas. The most common symptoms of PIOL include blurred or decreased vision due to tumor cells in the vitreous. Most cases of PIOL eventuate to central nervous system involvement (PCNSL) while only 20% of PCNSL lead to intraocular (PIOL) involvement. PIOL and PCNSL remain enigmas because both structures are immunologically privileged sites (the brain sits behind the blood–brain barrier and the retina sits behind the blood-retinal barrier) and so do not normally have immune cells trafficking through these struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliary Body Melanoma
Ciliary body melanoma is a type of cancer arising from the coloured part (uvea) of the eye. About 12% of uveal melanoma arise from the ciliary body. Clinical features It occurs most commonly in the sixth decade of life. * External signs include dilated episcleral blood vessels (''sentinel vessels''). Extraocular erosion may produce a dark mass beneath the conjunctiva. * Pressure on the lens by the enlarging tumor can cause astigmatism, subluxation of the lens and formation of a localised lens opacity. * The tumor can erode forward through the iris root and mimic an iris melanoma. * Retinal detachment can be rarely caused by posterior extension of the tumor. * Anterior uveitis is an uncommon presentation and occurs due to tumor necrosis. * Cirumferentially growing tumors carry a bad prognosis as they are diagnosed late. * At times the tumor is detected as an incidental finding during routine examination. The tumour is usually diagnosed by clinical examination with a slit-lamp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliary Body
The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The aqueous humor is produced in the non-pigmented portion of the ciliary body. The ciliary body is part of the uvea, the layer of tissue that delivers oxygen and nutrients to the eye tissues. The ciliary body joins the ora serrata of the choroid to the root of the iris.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. Structure The ciliary body is a ring-shaped thickening of tissue inside the eye that divides the posterior chamber from the vitreous body. It contains the ciliary muscle, vessels, and fibrous connective tissue. Folds on the inner ciliary epithelium are called ciliary processes, and these secrete aqueous humor into the posterior chamber. The aqueous humor then flows through the pupil into the anterior chamber. The ciliary bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iris (anatomy)
In humans and most mammals and birds, the iris (plural: ''irides'' or ''irises'') is a thin, annular structure in the eye, responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. Eye color is defined by the iris. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Structure The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles ( dilator pupillae), which pull the iris radially to enlarge the pupil, pulling it in folds. The sphincter pupillae is the opposing muscle of the dilator pupillae. The pupil's diameter, and thus the inner border of the iris, changes size when constricting or dilating. The outer border of the iris does not change size. The constricti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choroid
The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye, and contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract. The structure of the choroid is generally divided into four layers (classified in order of furthest away from the retina to closest): *Haller's layer - outermost layer of the choroid consisting of larger diameter blood vessels; *Sattler's layer - layer of medium diameter blood vessels; * Choriocapillaris - layer of capillaries; and *Bruch's membrane (synonyms: Lamina basalis, Complexus basalis, Lamina vitra) - innermost layer of the choroid. Blood supply There are two circulations of the eye: the retin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uveal Melanoma
Uveal melanoma is a type of eye cancer in the uvea of the eye. It is traditionally classed as originating in the Iris (anatomy), iris, choroid, and ciliary body, but can also be divided into class I (low metastatic risk) and class II (high metastatic risk). Symptoms include blurred vision, loss of vision or photopsia, but there may be no symptoms. Tumors arise from the pigment cells (melanocytes) that reside within the uvea and give color to the eye. These melanocytes are distinct from the retinal pigment epithelium cells underlying the retina that do not form melanomas. When eye melanoma is spread to distant parts of the body, the five-year survival rate is about 15%.Eye Cancer Survival Rates American Cancer Society, Last Medical Review: December 9, 2014 Last Revised: February 5, 2016 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs) or it may aim to prolong life or to reduce symptoms ( palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''medical oncology''. The term ''chemotherapy'' has come to connote non-specific usage of intracellular poisons to inhibit mitosis (cell division) or induce DNA damage, which is why inhibition of DNA repair can augment chemotherapy. The connotation of the word chemotherapy excludes more selective agents that block extracellular signals (signal transduction). The development of therapies with specific molecular or genetic targets, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Lymphoma
Orbital lymphoma is a common type of non-Hodgkin lymphoma that occurs near or on the eye. Common symptoms include decreased vision and uveitis. Orbital lymphoma can be diagnosed via a biopsy of the eye and is usually treated with radiotherapy or in combination with chemotherapy. Types There are two main types of intraocular lymphomas: primary central nervous system involvement (PCNSL) and primary central nervous system with ocular involvement (PCNSLO). The difference between PCNSL and PCNSLO is that PNSCL involves the central nervous system, while PCNSLO does not. 56-86% of orbital lymphomas are classified PCNSL and 15-25% are classified PCNSLO. PCNSLO is common in people who are severely immunosuppressed. Symptoms of this form of ocular lymphoma include painless decreased vision, sensitivity to light, a red eye, and floaters. Diagnosis is difficult due to its gradual onset and the fact that the symptoms are the same as other diseases. PCNSLO is usually bilateral, but someti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
