[Merkel carcinoma]

Area of Science:

• Oncology
• Dermatology
• Pathology

Background:

• Merkel carcinoma is a rare, aggressive cutaneous neuroendocrine tumor with increasing incidence.
• It presents as rapid growth, high recurrence risk, and early metastasis.
• Subtypes include Merkel polyomavirus-related (MCPyV) and UV-related, with risk factors like advanced age, male gender, light skin, and immunosuppression.

Purpose of the Study:

• To provide a comprehensive overview of Merkel carcinoma.
• To discuss diagnosis, staging, and current treatment strategies.
• To highlight the importance of monitoring and emerging biomarkers.

Main Methods:

• Diagnosis relies on histopathology and immunohistochemistry (CK20+, synaptophysin+).
• Staging involves imaging like PET-CT, MRI, and ultrasound, following AJCC 8th edition criteria.
• Treatment modalities include surgery, adjuvant radiotherapy, and immunotherapy for metastatic disease.

Main Results:

• Merkel carcinoma has a high recurrence rate (25-50%).
• Immunotherapy (anti-PD-1/PD-L1) has shown improved prognosis in metastatic cases.
• Ongoing evaluation of biomarkers like NSE and anti-MCPyV serology is underway.

Conclusions:

• Merkel carcinoma requires prompt diagnosis and a multidisciplinary treatment approach.
• Adjuvant therapies and immunotherapy are crucial for managing advanced stages.
• Long-term clinical and radiological monitoring is essential due to high recurrence rates.