Skin cancer is a malignant tumor that originates in the skin cells. The most common forms are basal cell carcinoma, squamous cell carcinoma and malignant melanoma, all treated at the Skin Cancer Center

Experts at Treating Rare Skin Cancers

Rare skin cancers are seen in just 1 percent of patients. Although uncommon, experts at the Skin Cancer Center at Froedtert & the Medical College of Wisconsin are highly experienced in their treatment.

  • Cancers in functionally and cosmetically sensitive areas (face, eyelids, nose, lips, ears)
  • Large cancers
  • Rare skin tumors such as Merkel cell carcinoma or dermatofibrosarcoma protuberans (DFSP)
  • Recurring or previously treated cancers
  • Advanced cancers
  • Skin cancers occurring in organ transplant recipients or other patients with a weakened immune system

Common Forms of Skin Cancer

Basal Cell Carcinoma

Basal cell carcinoma is the most common of all skin cancers. It occurs most often in the sixth to eight decades of life and usually affects sun-exposed skin such as the face, neck, ears and scalp. Basal cell carcinoma is very slow growing, gradually enlarging over months to years. It does not spread to lymph nodes or other organs; therefore, it is thought of as being less “cancerous” than tumors that are prone to spread to other areas. 

Basal cell carcinoma usually presents as a pimple or raised area that does not resolve and bleeds with minimal trauma like rubbing on a pillow or gentle washing of the affected skin. It may form a crust or small ulceration that does not heal. It is most common in individuals who are fair skinned with light hair and eye color who have a history of easy sunburning. People who have had a basal cell carcinoma are more likely to get others, compared to those individuals who have not had a basal cell carcinoma.

Squamous Cell Carcinoma Skin Cancer

Squamous cell carcinoma is the second most common of the skin cancers. The risk factors for developing squamous cell carcinoma are similar to those for basal cell carcinoma: fair skin, light hair and eye color and history of sun exposure. In addition, squamous cell carcinoma is common in people who take drugs to suppress their immune systems in the setting of organ transplantation and certain chronic immune conditions.

Compared to basal cell carcinoma, squamous cell carcinoma is typically faster growing, so patients notice a non-healing sore that seems to get bigger over a period of weeks, rather than months to years as seen in basal cell carcinoma. If left untreated, invasive squamous cell carcinoma has the potential to spread to other areas including lymph nodes and other organs outside of the skin. Therefore, prompt treatment of squamous cell carcinoma (usually surgery) is recommended.


Basal and squamous cell carcinomas are considered keratinocyte carcinomas. Keratinocytes are the cells that form in the skin. Keratoacanthoma is a skin tumor and is considered a form of squamous cell carcinoma.

Malignant Melanoma

Despite comprising a very small percentage of skin cancers, this quick-spreading malignancy causes the most deaths. Pigment-producing skin cells called melanocytes are the starting point. Sometimes it begins as an abnormal mole that turns cancerous.

Like the other skin cancers, it most often appears on fair-skinned people but people with other skin types are also at risk. Because of its tendency to spread quickly, treating malignant melanoma promptly is critical for best outcomes.

For more information about skin cancer, visit the American Academy of Dermatology, National Cancer Institute or the American Cancer Society.

Virtual Visits Are Available

Safe and convenient virtual visits by video let you get the care you need via a mobile device, tablet or computer wherever you are. We’ll gather your medical records for you and get our experts’ input so we can offer treatment options without an in-person visit. To schedule a virtual visit, call 1-866-680-0505.