Table of Contents
Basal cell cancers are sometimes hard to tell from benign skin conditions. For instance, occasionally they arise in unexposed skin, where they may look like an ordinary mole, cyst, or pimple. They may be particularly difficult to tell apart from benign cysts when they occur near the eyes.
Usually, basal cells grow slowly. They are rarely deadly. Most basal cell cancers do not need to be treated as an emergency. However, because late treatment can cause disfigurement, they should be removed as early as possible.
Basal cell cancers that are most likely to spread include those that are larger than 1 centimeter, scar-like, and those located on the cheek, nose, neck, earlobe, eyelid, or temple.
Some studies have shown that people with basal cell cancer may be at higher risk for second cancers, including melanoma, cancer of the lip, salivary glands, larynx, lung, breast, kidney, and non-Hodgkin's lymphoma. Those at higher risk for such cancers appear to be men and anyone diagnosed before 60 with basal cell cancer.
Squamous Cell Cancer and Bowen's Disease
Squamous cell cancer of the skin is even less common than basal cell cancers. About 200,000 to 300,000 people are diagnosed with this type of cancer each year.
Squamous cell cancer develops from flat, scale-like skin cells called keratinocytes, which lie under the top layer of the epidermis. Most squamous cell cancers occur on sun-exposed areas, especially the forehead, temple, ears, neck, and back of the hands. People who have spent considerable time sunbathing may develop them on their lower legs. Squamous cell cancers occur more often than basal cell cancers in African-Americans and Asians, and are more common in men than women.
Although squamous cell skin cancers usually can be removed completely with no risk of the cancer spreading, they are more likely, compared to basal cancers, to be invasive and to spread elsewhere in the body.
Types of squamous cell cancer:
- Squamous cell carcinoma in situ (also called Bowen's disease) is the earliest form of this type of cancer. The cancer has not invaded surrounding tissue. Cancer areas appear as large reddish patches (often over 1 inch) that are scaly and crusted.
- Invasive squamous cell carcinoma is highly likely to spread (metastasize). The skin cancer lesions can grow rapidly (over months) or slowly (over years). Eventually they break into an open wound (become ulcerated).
Review Date: 07/04/2010
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical
School; Physician, Massachusetts General Hospital. Also reviewed by
David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
