Skin cancers can develop when healthy skin cells divide and grow rapidly and uncontrollably, forming a tumor. This tumor can be benign (not spread to other parts of the body) or malignant (spread to distant organs and lymph nodes). Studies suggest that more than 3 million people in the country are affected by skin cancer. This type of cancer can be of different varieties. A few of the rare types of skin cancer are listed below:

Merkel Cell Carcinoma
Among the most aggressive and rare types of skin cancer is Merkel cell carcinoma. This type of cancer originates in the Merkel cells or the cells of the nerve endings. The nerve endings are what give the skin its sense of touch. Merkel cell carcinoma can develop in regions of the skin exposed to sunlight like the arms, face, neck, etc.

Also, being affected with the Merkel cell polyomavirus (MCV), old age, having a weak immune system, and other risk factors can contribute to the development of Merkel cell carcinoma. The early signs of this cancer include the presence of a fast-growing tumor that can be pink, purple, or red in color.

Kaposi Sarcoma (KS)
Another one of the rare types of skin cancer is Kaposi sarcoma or KS. This type of cancer is triggered by the Human Herpesvirus 8 (Kaposi sarcoma-associated Herpesvirus). One may experience the presence of purple, brown, or red tumors on the skin and lesions on the mucosal surfaces like mouth, intestinal tract, etc. KS can turn fatal if the cancer metastasizes to the liver or the digestive tract. There are four types of KS:

• Mediterranean or Classic Kaposi Sarcoma: Here, the lesions are commonly present on the legs, soles, and feet of the patient. It is more likely to affect males than females. Also, the elderly are more at risk for classic KS.
• Iatrogenic or Transplant-Related Kaposi Sarcoma: Sometimes, the immune system of a person is compromised due to organ transplants. It then results in the development of Iatrogenic KS.
• AIDS-Related Kaposi Sarcoma: This form of KS occurs in individuals with AIDS. HIV destroys the immune system, making the body more prone to develop Kaposi sarcoma.
• Endemic Kaposi Sarcoma: This cancer is also called African Kaposi sarcoma, as it is more prevalent in people from those regions. Malnutrition, malaria, infections, and exposure to other endemic diseases can weaken the immune system, leading to the occurrence of KS.

Cutaneous Lymphoma
This condition is a form of non-Hodgkin’s lymphoma and is among the rare types of skin cancer. Usually, lymphoma starts in the lymph nodes. These nodes produce T-cells and B-cells (lymphocytes) that fight off infection in the body. Sometimes, the lymphoma develops in the lymphoid tissue such as spleen, skin, bone marrow, etc.

While the main cause of cutaneous lymphoma is DNA mutation, certain risk factors like gender, race, age, having a weakened immune system, among others, might increase the chances of it occurring. The symptoms of cutaneous lymphoma include the appearance of rashes and bumps on the skin.

Actinic Keratosis
Actinic Keratosis are clusters that develop on the skin that has been exposed to UV radiation. They are pre-cancerous and, if not treated, can lead to squamous cell carcinoma.

Skin Adnexal Tumors
This form of cancer affects the tissue structures that are adjacent to the skin. Tumors can form in the sebaceous glands, hair follicles, eccrine glands, apocrine glands, etc. This form of cancer is generally a result of genetic conditions and sporadic.