Merkel cell carcinoma is a rare type of skin cancer that begins in the Merkel cells. Found at the base of the outermost layer of skin, Merkel cells are connected to the nerve endings in the skin that are responsible for the sense of touch. The lymph nodes, brain, bones, liver, and lungs can be affected by Merkel cell carcinoma if it is not diagnosed and treated early.
Merkel cell carcinoma most often appears on the face, head, and neck, but it can develop anywhere on the body. Merkel cell carcinoma appears as a flesh colored or bluish red nodules.
If the doctor suspects Merkel cell carcinoma has spread to the lymph nodes, a specialized test called a sentinel node biopsy may be recommended. During this procedure, a dye is injected into the lymphatic system. The dye then flows through the lymph nodes and bonds to cancerous cells like a highlighter if cancer is present. The ares affected by the die are removed and analyzed in order to determine the best course of treatment.