[Merkel cell skin carcinoma]

Area of Science:

• Dermatology and Oncology
• Rare Cancers
• Skin Tumors

Context:

• Merkel cell carcinoma (MCC) is a rare but aggressive skin neoplasm.
• It predominantly affects elderly Caucasian males on sun-exposed skin.
• Incidence is significantly higher and at a younger age in immunocompromised patients, often with a fatal outcome.

Purpose:

• To summarize the epidemiology, clinical presentation, diagnosis, and treatment of Merkel cell carcinoma.
• To highlight the aggressive nature and poor prognosis of MCC, especially in immunocompromised individuals.
• To discuss current therapeutic mainstays and future directions in MCC management.

Summary:

• MCC incidence is rising, exceeding that of cutaneous melanoma, with over a third of patients dying from the disease.
• Malignant transformation is linked to Merkel cell polyomavirus; diagnosis requires histological and immunohistochemical confirmation.
• Early stage presentation can be deceptive, masking extensive invasion, leading to delayed diagnosis and treatment challenges.

Impact:

• Radical excision and adjuvant radiotherapy are the primary treatments, though chemotherapy efficacy is limited.
• Tumor staging at diagnosis is the most critical prognostic factor.
• Future strategies may include polyomavirus vaccination, targeted therapies like antisense oligonucleotides or microRNAs, and modulation of tumor suppressor gene expression for MCC elimination.