The following sizes are used to describe intraocular melanoma:
The tumor is 5 to 16 millimeters in diameter and from 1 to 3 millimeters thick.
Millimeters (mm). A sharp pencil point is about 1 mm, a new crayon point is about 2 mm, and a new pencil eraser is about 5 mm.
The tumor is 16 millimeters or smaller in diameter and from 3.1 to 8 millimeters thick.
The tumor is:
- more than 8 millimeters thick and any diameter; or
- at least 2 millimeters thick and more than 16 millimeters in diameter.
Though most intraocular melanoma tumors are raised, some are flat. These diffuse tumors grow widely across the uvea.
There are three ways that cancer spreads in the body.
The three ways that cancer spreads in the body are:
- Through tissue. Cancer invades the surrounding normal tissue.
- Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
- Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
Intraocular melanoma may spread to nearby tissues or to other parts of the body.
If intraocular melanoma spreads to the optic nerve or nearby tissue of the eye socket, it is called extraocular extension. Intraocular melanoma may also be metastatic and spread to the liver, lung, or bone, or to areas under the skin.
There are two staging systems for intraocular melanoma.
Intraocular melanoma has two staging systems. The staging system used depends on where in the eye the cancer first formed:
- Ciliary body and choroid.