Merkel cell carcinoma (also known as a “Cutaneous apudoma,” “Primary neuroendocrine carcinoma of the skin,” Primary small cell carcinoma of the skin, and “Trabecular carcinoma of the skin is a rare and highly aggressive cancer in which malignant cancer cells develop on or just beneath the skin and in hair follicles.
Merkel cell carcinoma (also known as a “Cutaneous apudoma,” “Primary neuroendocrine carcinoma of the skin,” Primary small cell carcinoma of the skin, and “Trabecular carcinoma of the skin is a rare and highly aggressive cancer in which malignant cancer cells develop on or just beneath the skin and in hair follicles.
• The majority of Merkel cell carcinomas appear to be caused in part by a newly discovered virus, Merkel cell polyomavirus or MCV. Direct evidence for this comes from studies showing that inhibition of MCV proteins causes MCV-infected Merkel carcinoma cells to die but has no effect on tumor cells from Merkel cell carcinomas that are not infected with the virus
• This cancer is a type of neuroendocrine tumor, like small cell lung cancer. Once it has metastasized to the lymph nodes, the 5-year survival rate for a patient is about 50 percent. A patient with a small tumor (less than 2 cm) that has not metastasized to the lymph nodes may have a 5-year survival rate of more than 80 percent. Up to half of patients suffer a recurrence.
• Merkel cell carcinoma (MCC) occurs most often on the sun-exposed face, head, and neck. It usually appears as a firm, painless, nodule, or tumor. These flesh-colored, red, or blue tumors vary in size from 5 mm (less than a quarter of an inch) to more than 5 cm (2 inches). The tumor grows rapidly. About half of all Merkel cell cancers occur on the sun-exposed areas of the head and neck, while one-third begin on the legs, and 15% occur on the arms. The cancer may also begin on other parts of the body, such as the trunk.
• From initial onset, Merkel cell cancer metastasizes quickly and spreads to other parts of the body, tending towards the regional lymph nodes. The tumor tends to invade underlying subcutaneous fat, fascia, and muscle. It can also metastasize to the liver, lungs, brain or bones.