Merkel Cell Carcinoma

Definition

Merkel cell carcinoma is a rare and aggressive type of skin cancer that starts in Merkel cells, which are located in the top layer of the skin and are involved in the sensation of touch.

Characteristics

This cancer often appears as a painless, firm, flesh-colored or bluish-red nodule on sun-exposed areas like the face, neck, or arms. It grows rapidly and can spread quickly to lymph nodes and other parts of the body. Risk factors include older age, excessive sun exposure, weakened immune system, and infection with Merkel cell polyomavirus.

Diagnosis and Prognosis

Diagnosis involves skin biopsy, imaging tests to assess spread, and sometimes lymph node biopsy. Prognosis depends on the stage at diagnosis. Early-stage Merkel cell carcinoma has a better outcome, while advanced disease can be challenging to treat.

Treatment

Treatment usually includes surgery to remove the tumor, often followed by radiation therapy. Immunotherapy has become an important option for advanced or metastatic disease, significantly improving outcomes in some patients.

Last Revised: 12 May , 2025