Skin Cancer

Definition of skin cancer: Cancer that forms in the tissues of the skin. There are several types of skin cancer. Skin cancer that forms in melanocytes (skin cells that make pigment) is called melanoma. Skin cancer that forms in the lower part of the epidermis (the outer layer of the skin) is called basal cell carcinoma. Skin cancer that forms in squamous cells (flat cells that form the surface of the skin) is called squamous cell carcinoma. Skin cancer that forms in neuroendocrine cells (cells that release hormones in response to signals from the nervous system) is called neuroendocrine carcinoma of the skin. Most skin cancers form in older people on parts of the body exposed to the sun or in people who have weakened immune systems.

It is estimated that more than 3 million people in the US are diagnosed with non-melanoma skin cancer each year.

The Following Stages Are Used For Nonmelanoma Skin Cancer That Is Not On The Eyelid:

Stage 0 (Carcinoma In Situ)

In stage 0, abnormal cells are found in the squamous cell or basal cell layer of the epidermis (topmost layer of the skin). These abnormal cells may become cancer and spread into nearby normal tissue.

Stage I

In stage I, cancer has formed. The tumor is not larger than 2 centimeters at its widest point and may have one high-risk feature.

Stage II

In stage II, the tumor is either:

  • larger than 2 centimeters at its widest point; or
  • any size and has two or more high-risk features.

Stage III

In stage III:

  • The tumor has spread to the jaw, eye socket, or side of the skull. Cancer may have spread to one lymph node on the same side of the body as the tumor. The lymph node is not larger than 3 centimeters.

Stage IV

In stage IV, one of the following is true:

  • The tumor is any size and may have spread to the jaw, eye socket, or side of the skullCancer has spread to one lymph node on the same side of the body as the tumor and the affected node is larger than 3 centimeters but not larger than 6 centimeters, or cancer has spread to more than one lymph node on one or both sides of the body and the affected nodes are not larger than 6 centimeters; or
  • The tumor is any size and may have spread to the jaw, eye socket, skull, spine, or ribs. Cancer has spread to one lymph node that is larger than 6 centimeters; or

The Following Stages Are Used For Nonmelanoma Skin Cancer On The Eyelid:

Stage 0 (Carcinoma In Situ)

In stage 0, abnormal cells are found in the epidermis (topmost layer of the skin). These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

Stage I is divided into stages IA, IB, and IC.

Stage II

In stage II, one of the following is true:

  • The tumor is larger than 20 millimeters.
  • The tumor has spread to nearby parts of the eye or eye socket.
  • The tumor has spread to spaces around the nerves in the eyelid.

Stage III

Stage III is divided into stages IIIA, IIIB, and IIIC.

Stage IV

The tumor has spread to distant parts of the body.


All information was taken from the NCI (National Cancer Institute)