Is ocular melanoma the same as skin melanoma?

Yes: Melanoma occurs when melanocytes (the pigment producing cells) found in the body become damaged and start to divide out of control becoming cancer. Melanocytes are found in the skin, the middle layer of the eye (the uvea), the inner ear, brain (meninges), bones, and heart.

Not really: Ocular melanoma starts in the back of the eye and is genetically and clinically different than the more common skin melanoma. Although they look fairly similar under the microscope, their typical clinical patterns are very different.

In some ways: Yes, in some ways it is. Recent research has demonstrated various ways in how it is different. For example, skin melanoma and ocular melanoma have different gene mutation signatures. Second, ocular melanoma almost exclusively spreads to the liver.

Almost: All melanomas are due to a cancerous mutation of the pigmented cells of the body. Each has some characteristics of the tissue from which it is derived. So skin and ocular melanomas are almost the same but spread in slightly different way when untreated. However both types can be lethal.