Melanoma is cancer that develops in skin cells called melanocytes, the cells that contain pigment, according to the National Cancer Institute. Once cancer has been diagnosed, it is staged. Staging is a standardized system that describes the spread and extent of the cancer and helps guide treatment and prognosis. For melanoma, there are five stages, from Stage 0 to IV, with the highest stage being the most severe.
Stage IIIA
In Stage IIIA melanoma, the cancer has spread to one to three lymph nodes near the skin lesion, but the nodes are not swollen, and the cancer is only able to be seen microscopically, according to the American Cancer Society. The top layer of skin is still present, and although lesions of this stage are typically thick, the level of thickness is irrelevant. No distant organs are cancerous.
Stage IIIB
The second sub-stage of the third stage of melanoma, Stage IIIB, can be diagnosed in a number of situations. This stage includes cancers that are similar to those of Stage IIIA but the lesion is ulcerated, meaning the top layer of skin is missing. It can also be diagnosed when the lesion is not ulcerated, with cancer in one to three adjoining lymph nodes that are also swollen; or if the melanoma has spread to skin or lymphatic channels near the original tumor, with or without ulceration, and the lymph nodes are not cancerous. The cancer has not spread to distant organs or parts of the body.
Stage IIIC
Stage IIIC melanoma includes lesions that are ulcerated and is in one to three swollen lymph nodes adjacent to the primary tumor. It may also be diagnosed if the cancer has spread to four or more lymph nodes, bunches of adjacent lymph nodes or has spread to the skin or lymph channels around the original lesion as well as lymph nodes that are swollen. The cancer has not metastasized to distant organs in the body.
Stage IV
The National Cancer Institute describes the final stage of melanoma, Stage IV, as melanoma that has spread to distant organs or parts of the body.
About this Author
After graduating with a bachelor’s degree in psychology and women’s studies, Jaime Herndon pursued a Master of Science in clinical health psychology, and recently completed her M.P.H. in maternal-child health from UNC. Her interests include women’s cancers, pediatric oncology, and women’s health.
