Medium Choroidal Melanoma
What does it look like ~
The appearance of melanoma depends on its size and location, whether it is in the front of the eye, in the iris, or in the back of the eye, the choroid. Iris melanoma appears as a brown or yellow nodule on the iris, sometimes with discoloration of the remainder of the iris due to tumor seeds. Iris melanoma is usually visible to the patient. Iris melanoma can cause glaucoma and cataract, but most patients with glaucoma or cataract do not have melanoma. Choroidal melanoma appears as a brown or yellow tumor in the back of the eye and is not visible to the patient. Based on tumor thickness, choroidal melanoma is classified into small (0-3mm), medium (3-8mm), and large (>8mm). Small tumors might resemble a benign choroidal nevus or freckle.
Risk factors that identify which small tumors are melanoma include:
• Thickness > 2 mm
• Subretinal fluid over the tumor
• Symptoms of flashing lights, floaters, or vision loss
• Orange pigment over the tumor
• Margin of the tumor near the optic disc
Large Choroidal Melanoma
These important factors were initially identified by our team on the Ocular Oncology Service at Wills Eye Institute. Our findings are based on years of research. These factors have been published and tested in various reports in ophthalmic medical journals such as Ophthalmology, Archives of Ophthalmology, Current Opinion in Ophthalmology and others. Using these factors to identify small melanoma could be life-saving.
Medium and large choroidal melanoma can assume a dome shape or even a mushroom shape appearance as they enlarge. Often they produce overlying subretinal fluid (retinal detachment) that is associated with vision loss. Growth of the tumor through the wall of the eye into the overlying soft tissues is called extraocular extension and is more worrisome.