Sebaceous carcinoma (SC) is a rare but aggressive form of malignant skin cancer. It develops on our sebaceous glands, which are small glands in the skin which produce sebum, an oily substance to help lubricate and waterproof the skin. They are found throughout the body (except on the palms, soles and top of the feet and the lower lip although they are found in the greatest number of the face, upper neck and chest.
About three fourths of all sebaceous carcinomas are found on the eyelid, with other common areas being the face and the neck although they can develop anywhere on the body where there are sebaceous glands.
When SC develops around the eye, it is usually on the upper eyelid. It may look like a sty or a case of pinkeye. It is usually painless however, if untreated, the eyelid can turn outward or inward, your eyelashes can fall out and your vision may become distorted.
On other areas of the body, SC is pink or reddish-yellow mass, which may bleed.
SC is a slow growing cancer.
It is sometimes mistaken for benign conditions, such as chalazion and, if so, diagnosis can be delayed, increasing the risk of the cancer spreading. If your doctor suspects SC, he will perform a biopsy, removing some or all of the lesion to examine under a microscope.
Exposure to the sun's UV rays is thought to play a role in SC. Additional risk factors include:
Weakened immune system - those with a weakened immune system, either from disease or as a result of medications, are at a higher risk of developing SC.
Previous radiation therapy
- those who received radiation as a child have a higher risk of being diagnosed with SC later in life. Some children who receive radiation for retinoblastoma, a cancer in the eye, may develop SC.
Muir-Torre syndrome - this rare medical condition increases the risk of developing several cancers, including colon, SC and cancers of the uterus, stomach, ovaries, intestine, urinary tract, liver and bile duct.
Some research has also shown that HPV infections may increase the risk of developing SC.
SC is most often seen in Caucasian people who are 60 years old and older and is more common in women. Some studies have shown a higher incident rate in the Asian and Indian population. It is very rare for someone under the age of 30 to develop SC.
Treatment for SC is similar to that of other skin cancers:
Lymph node dissection (if the cancer has spread to nearby lymph nodes)
Radiation (when surgery is not an option or cancer has spread to other areas of the body)
As with other skin cancers, early detection is important. When detected and treated early, survival rates are high, however, SC can return or spread to other areas of the body so it is important to have regular check-ups with your dermatologist.
"Early Onset Sebaceous Carcinoma," 2011, Dongjin Sun, Sara A. Kaltreider, Federico Gonzalez-Fernandez, Diagnostic Pathology
"Rapidly Growing Extraocular Sebacrious Carcinoma Occurring During Pregnancy," 2008, August, Sudip Kumar Ghosh
M.D. et al, Dermatology Online Journal, Volume 14, Number 8
"Sebaceous Carcinoma," Date Unknown, Staff Writer, Optocase: Optometry Continuing Education
"What is Sebaceous Carcinoma?" Date Unknown, Staff Writer, SkinCancerNet, American Academy of Dermatology