![colordial nevus colordial nevus](https://ijdvl.com/content/126/1997/63/3/Images/ijdvl_1997_63_3_183_4559_2.jpg)
The presence of fluid over the lesion increases the likelihood that it is a melanoma. However, we do know that some nevi do grow slightly. If a lesion grows in diameter and/or height, melanoma will be suspected. Height can vary, also, and some nevi are fairly elevated. The more elevated the lesion, the more likely it is to be a melanoma. The flatter the lesion, the more likely it is to be a nevus. Diameter can vary, however, and some melanomas can have a relatively small diameter while nevi can have a relatively large diameter. The larger the lesion, the more likely it is to be a melanoma. In general, the smaller the diameter of the lesion, the more likely it is to be a nevus. Nevi can possess some characteristics that are suggestive of a melanoma, so the distinction between a nevus and a melanoma is not always straightforward. When a retina specialist identifies an abnormally pigmented lesion in the back part of the eye on a dilated eye exam, he/she looks for various characteristics that help to distinguish between a choroidal nevus and a choroidal melanoma. Also, you can probably tell that it is elevated rather than flat: How can the doctor tell between a nevus and a melanoma? Notice the large size in contrast to the nevus pictured above. The photograph to the left shows a choroidal melanoma. They can threaten both the vision (by growing and interfering with retinal function) and the patient’s general health (by “metastasizing”, or spreading to other parts of the body). Like choroidal nevi, choroidal melanomas are usually brown in color, but they can also be amelanotic, with a more whitish color. The photograph to the right shows a typical choroidal nevus:Ī choroidal melanoma is a malignant (cancerous) growth in the back part of the eye. They can be “amelanotic”, lacking the more typical brown color and possessing a more whitish color, instead. Choroidal nevi (“nevi” is plural for “nevus”) are usually brown and fairly flat, similar to a mole that you might find on your skin. It is a benign growth of cells called “melanocytes”. A choroidal nevus is like a mole in the back part of the eye, in a layer called the choroid, which is located behind the retina.