Eye

Primary eye cancers can occur at any age, but most occur in people over age 50.1 Cancers that spread to the eye from another part of the body are actually more common than primary eye cancers.1
 * **Epidemiolgy:** || Most cancers of the eye and orbit in adults are melanomas, with lymphomas being the next most common.1
 * Basal and Squamous Cell Carcinoma most frequently occur on the lower eyelid and medial canthus.2
 * Malignant melanoma is the most common primary malignant tumor of the eye, the overall incidence of uveal melanoma is only 5 to 7 cases per million people each year. Average age at diagnosis is 55 years old. Tumors of the posterior uvea account for more than 90% of cases, with the majority being choroidal melanoma.2
 * Retinoblastoma is a malignant embryonal neoplasm arising in the retina during fetal life or early childhood. It occurs unilaterally in 2/3 of patients and bilaterally in 1/3. More than 90% of tumors occur before age 3, Median age is 8 months for patients with bilateral disease and 26 months for unilateral disease.1
 * Optic Glioma account for 1% to 5% of intracranial gliomas and 4% of orbital tumors. They occur most frequently in children, with 75%in the irst decade and 90%in the first two decades of life.2
 * Malignant Lymphoma of the orbit accounts for 1% of cases of nonHodgkin's lymphoma and 10% of all orbital tumors.1
 * Lacrimal gland tumors are rare.2 ||
 * **Etiology:** || == Risk factors for primary intraocular melanoma1 ==
 * Race/ethnicity
 * The risk of intraocular melanoma is much higher in whites than in African Americans or Asian Americans.
 * Eye color
 * People with light colored eyes also have an increased risk of intraocular melanoma. People with blue eyes are somewhat more likely to develop melanoma of the eye than are people with brown eyes.
 * Certain inherited conditions
 * Dysplastic nevus syndrome, in which people have abnormal moles of the skin and an increased risk of skin melanoma, may also increase the risk for developing melanoma of the eye.
 * People with abnormal brown spots on the uvea (known as oculodermal melanocytosis or nevus of Ota) also have an increased risk of developing eye melanoma.
 * Eye melanomas can run in some families who do not have these conditions, but this is very rare.
 * Sun exposure
 * Although too much exposure to sunlight (or sunlamps) has been proposed as a possible risk factor for melanoma of the eye, it has never been proven.
 * Certain occupations
 * Some studies have suggested that welders, farmers, fishermen, chemical workers, and laundry workers may have a higher risk of eye melanoma, but none of these links has been proven conclusively.

Risk factors for primary intraocular lymphoma1

 * The only known risk factor for primary lymphoma of the eye is having a weakened immune system. Examples include patients with the acquired immunodeficiency syndrome (AIDS) as well as people who take anti-rejection drugs after organ or tissue transplants.

Risk factors for Basal and Squamous Cell Carcinoma1

 * Patients with sun exposure and who are immunosuppressed have an increased incidence of these cancers.

Risk factors for Retinoblastoma1
Example of retinoblastoma presentation. || Mixed Cell (65%): Epithelioid Cell (5%): Retinoblastoma : Eyelid: Intraocular Melanoma:
 * A family history is present in 10% of patients. It is the classic genetically inhereted pediatric cancer. Results from the loss or mutation of both copies of the RBI gene, located at 13q14. ||
 * **Signs & Symptoms:** || * Many patients with eye melanoma don't have symptoms unless the cancer grows in certain parts of the eye or becomes more advanced. Signs and symptoms of eye melanomas can include:1
 * Problems with vision (blurry vision or sudden loss of vision)
 * Floaters (spots or squiggles drifting in the field of vision) or flashes of light
 * Visual field loss (losing part of your field of sight)
 * A growing dark spot on the iris
 * Change in the size or shape of the pupil
 * Change in position of the eyeball within its socket
 * Bulging of the eye
 * Change in the way the eye moves within the socket
 * Regular eye exams are an important part of everyone's health care, even if they have no symptoms.1
 * Some doctors may recommend yearly eye exams for those who may be at higher risk of eye cancers, such as people with dysplastic nevus syndrome.1
 * People who notice a dark spot on their iris (colored part of the eye) should have a doctor look at it, especially if it is getting bigger.
 * Pain is rare except in cases of massive spread outside the eye.1
 * In such cases, bulging or a change in the position of the eye may also be noted.
 * Retinoblastomas are usually found because a parent or pediatrician notices a child's eye looks unusual.1
 * A white glare of the eye may be noticed by a parent after a flash photograph is taken or by the child's doctor during a routine eye exam. This is the most common early sign of retinoblastoma.
 * **Diagnostic Procedures:** || Diagnostic workup ocular cancer requires a history, a physical examination (including a complete ophthalmologic examination with retinal drawings and photographs), along with ultrasound studies and a complete examination of the eye. Diagnosis of malignant melanoma is also preformed similarly, but may include a biopsy.3 ||
 * **Histology:** || Ocular Melanoma:
 * Spindle Cell (30%):
 * Type A - Best prognosis, 5 year overall survival (OS) rate = 95%
 * Type B - Intermediate prognosis, 5 year OS rate = 85%
 * Contains spindle and epithelioid cells, 5 year OS rate = 83%
 * Worse prognosis, 5 year OS rate = 60%
 * It is a small round blue cell tumor derived from cells of neural crest origin.
 * The histology of cancers of the eyelid can be basal cell or squamous cell.
 * Spindle cell melanoma (cells are longer and tapered at the ends)
 * Epithelioid melanoma (cells are oval-shaped)
 * Mixed cell melanoma (both spindle and epithelioid)4 ||
 * **Lymph node drainage:** || Research is still underway to determining the role of lymphatics of eye cancer. Studies to identify lymphatic channels are being performed. Molecular biology and endothelial cell markers are being used to determine lymphatics. Schlemm's canal, also known as canal of Schlemm or the scleral venous sinus, acts as a lymph node, is a circular channel in the eye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream via the anterior ciliary veins .5 ||
 * **Metastatic spread:** || ** Metastatic Tumors of the Globe ** 6
 * Carcinoma
 * Neuroblastoma
 * Melanoma
 * Carcinoid tumor
 * Leukemia/lymphoma
 * Metastatic Tumors of Conjunctiva ** 6
 * Distant carcinomas
 * Leukemia
 * Metastatic Tumors of Eyelids ** 6
 * Exceptionally rare
 * Metastatic Tumors of the Orbit ** 6
 * Distant carcinomas (e.g., breast, lung, gastrointestinal tract)
 * Neuroblastoma
 * Leukemia (granulocytic sarcoma)
 * Carcinoid tumor
 * Metastatic melanoma ||
 * **Grading:** || Histologic grade (G) for cancers of the eye differ. For example, sarcoma of the orbit is graded according to the following guidelines:
 * Orbit Sarcoma Histologic Grade (G) ** 7

GX - Grade cannot be assessed G1 - Well differentiated G2 - Moderately differentiated G3 - Poorly differentiated G4 - Undifferentiated ||
 * **Staging:** || Staging for the various cancers of the eye differ. For example, sarcoma of the orbit is staged according to the following guidelines: 7

TX - Primary tumor cannot be assessed T0 - No evidence of primary tumor T1 - Tumor 15 mm or less in greatest dimension T2 - Tumor more than 15 m in greatest dimension without invasion of globe or bony wall T3 - Tumor of any size with invasion of orbital tissues and/or bony walls T4 - Tumor invasion of globe or periorbital structure, such as eyelids, temporal fossa, nasal cavity and paranasal sinuses, and/or central nervous system
 * Primary Tumor (T) **

NX - Regional lymph nodes cannot be assessed N0 - No regional lymph node metastasis N1 Regional lymph node metastasis
 * Regional Lymph Nodes (N) **

MX - Distant metastasis cannot be assessed M0 - No distant metastasis M1 - Distant metastasis
 * Distant Metastasis (M) **

No stage grouping is presently recommended || For tumors of the posterior Uvea brachytherapy is commonly used to decrease the chance of vision impairment for metastatic tumors of the posterior Uvea chemo is often used, radiation can be used in conjunction with chemo or alone. For retinoblastomas chemotherapy and radiation may both be utilized. For less advanced cases external beam alone can be used. Lateral fields are common treating the whole eye up to 45 Gy. In more advanced cases chemo therapy may be used in conjunction with brachytherapy. For optic gliomas surgery followed by radiation therapy with doses of 45Gy in children and 50Gy in adults is utilized. || Retina- 55Gy Cornea- 50Gy5 ||
 * Stage Grouping **
 * **Radiation side effects:** || Side effects from the radiation treatments that are specific to the eye may include cataracts, atrphy of the optic nerve, and in extreme cases blindness. ||
 * **Prognosis:** || The prognostic factors in the eye vary due to the number of different malignancies that are in the eye. A few of the common factors include poor visual acuity or loss of vision, orbital invasion, involvement of the optic nerve, size, and growth pattern. Cell differentiation does not play a big part in prognosis of tumors of the eye. ||
 * **Treatments:** || For carcinomas of the eyelid, radiation therapy is commonly used, lower energies are used and dose is commonly taken to 45-60Gy. If the tumor is located in the meibomian gland dose is taken up to 65Gy.
 * **TD 5/5:** || Lens of the eye - 5Gy
 * **References:** || # Eye Cancer (Melanoma and Lymphoma). American Cancer Society. Available at: []. Accessed: May 30, 2012.
 * 1) Bentel GC. //Radiation Therapy Planning//. 2nd ed. The McGraw-Hill Companies; 1996: 314-318.
 * 2) Chao KSC, Perez CA, Brady LW. //Radiation Oncology Management Decisions//. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2002: 175-187.
 * 3) Perez CA, Brady LA. //Principles and Practice of Radiation Oncology//. 5th ed. Philadelphia, PA: Lippincott Williams &Wilkins; 2008: 778 -796.
 * 4) Washington CM, Leaver D. //Principles and Practice of Radiation Therapy//. 2nd ed. St. Louis, Missouri; Mosby Inc; 2004: 640-641.
 * 5) Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG. //Abeloff's Clinical Oncology//. 4th ed. Philadelphia, PA: Churchill Livingstone; 2008.
 * 6) American Joint Committee on Cancer. //AJCC Cancer Staging Manual//. 6th ed. New York, NY: Springer; 2002. ||

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