5 Types of Skin Cancer You Didn’t Know Existed
Skin cancer awareness has greatly increased over the last few decades. Many people are aware of the three most common skin cancer types: basal cell carcinoma, squamous cell carcinoma and melanoma. However, there are many types of skin cancer beyond the classic triad. Last year we lost musician, Jimmy Buffett to Merkel cell carcinoma, which gained media attention and brought awareness to one such cancer. Here I will introduce you to Merkel cell carcinoma and four other rare skin cancers. These are just more reasons to continue seeing your dermatologist for regular skin exams.
- Merkel Cell Carcinoma:
This is a rare, aggressive skin cancer that was thought to arise from the Merkel cell, a cell involved in our touch receptors. However, recent research is showing that Merkel cell may not evolve from the normal Merkel cell but may just share similar features under the microscope. These tumors generally arise in sun damaged areas of the head and neck as a painless pink to red papule or nodule. They tend to be rapidly changing or enlarging. The median age of diagnosis is 75-80 but can occur at any age. Treatment of Merkel cell carcinoma includes surgery, along with possible immunotherapy, chemotherapy, or radiation.
- Dermatofibrosarcoma Protuberans (DFSP):
This is a soft tissue sarcoma that arises from the deeper level of the skin known as the dermis. They are slow growing and have a high rate of recurrence, however, very rarely metastasizing to other areas of the body. Unlike other types of skin cancer DFSP is most common in young to middle-aged adults. Usually, they present as a slow growing red to brown firm bump several centimeters in size. Treatment primarily involves surgical removal, but occasionally radiation may be recommended, or a medication called Imatinib may be used for tumors that cannot undergo complete removal.
- Microcystic Adnexal Carcinoma (MAC):
Microcystic adnexal carcinoma is a rare, locally aggressive cancer arising from the sweat gland. Like DFSP these tumors are also very unlikely to metastasize to other areas. MACs usually present in young to middle aged adults but have been reported in children as young as 11. They are slightly more common in females. Most commonly MACs occur on the head and neck, especially near the lips. These cancers are subtle at first, and are usually a slow growing, firm, papule that may be skin colored or have a yellowish hue with increased blood vessels. Treatment is Mohs micrographic surgery, as these cancers have borders that are not well defined.
- Atypical Fibroxanthoma (AFX):
This is a rare, low-grade sarcoma that arises from the dermal layer of skin. It presents as a rapidly enlarging red or pink bump that may bleed, although usually they are asymptomatic. AFX tend to occur on the head and neck in sun exposed areas and in patients older than 60. Risk factors for developing AFX include UV exposure, burns and immunosuppression. Mohs micrographic surgery is the treatment of choice, with radiation therapy also being used for tumors that cannot be completely removed.
- Sebaceous Carcinoma:
This cancer arises from the oil glands, or sebaceous glands, of the skin. These can appear as a yellowish bump or thickened area on the skin that may bleed. Most commonly these occur on the eyelids but can occur in other locations on the head, neck, and trunk. Sebaceous carcinoma tends to occur in patients 60 years and older. These are also seen much more frequently in patients with a genetic condition called Muir-Torre syndrome. These patients are also at significant increased risk of colon cancer, along with other internal malignancies. Mohs micrographic surgery is the treatment of choice with radiation occasionally being used for lesions not able to be removed with Mohs.
- Caitlyn Foote, MD, FAAD