Merkel Cell Carcinoma Assessment and Referral in London

Understanding Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare and aggressive form of skin cancer. It arises from Merkel cells—specialised nerve-associated cells in the skin responsible for touch sensation. MCC is known for its rapid growth and high likelihood of spreading (metastasising) to lymph nodes and other organs if not treated promptly.

Causes and Risk Factors

The exact cause of MCC is not fully understood, but several contributing factors are recognised:

• Sun exposure: Chronic ultraviolet (UV) damage is a major risk factor.
• Merkel cell polyomavirus: Detected in many MCC tumours, suggesting a viral role in cancer development.
• Weakened immune system: Patients on immunosuppressive medication or with conditions like HIV are at higher risk.
• Older age: Most cases occur in people over 65.
• Fair skin: Higher risk in lighter-skinned individuals with cumulative sun exposure.

Symptoms of Merkel Cell Carcinoma

MCC often appears as a skin lump that:

• Is firm, painless, and dome-shaped
• Grows quickly over weeks to months
• Is red, purple, bluish, or skin-coloured
• Occurs most often on sun-exposed areas such as the head, neck, and arms

Because MCC can resemble cysts, lipomas, or other harmless lumps, early recognition and biopsy are essential.

Merkel Cell Carcinoma Diagnosis

Diagnosis requires prompt dermatological assessment and biopsy. Tests include:

• Clinical examination: Checking suspicious lumps and lymph nodes.
• Dermoscopy: Magnified skin imaging to assess features.
• Skin biopsy: Definitive test, confirming MCC under a microscope.
• Imaging (CT, PET, MRI): Used for staging and detecting spread.

Treatment Options for Merkel Cell Carcinoma

MCC is best managed through a multidisciplinary team (MDT) approach in specialist cancer centres. Treatments include:

• Surgical excision: Removing the tumour with a margin of healthy tissue, often combined with lymph node biopsy or removal.
• Radiotherapy: Used to destroy remaining cancer cells or when surgery is not possible.
• Chemotherapy: Occasionally used, though newer treatments are often preferred.
• Immunotherapy: Checkpoint inhibitors (such as avelumab or pembrolizumab) have shown good outcomes in advanced MCC.

Prognosis

The outlook depends on how early MCC is detected and treated. Localised tumours have better outcomes, while advanced disease carries a higher risk of recurrence and spread. Regular follow-up is essential.

Living with Merkel Cell Carcinoma

Patients require long-term monitoring, ongoing skin checks, and emotional support. Coping with MCC can be challenging, and psychological care, alongside cancer support services, plays a vital role in patient wellbeing.

Your first visit — what to expect

1. History: Assessment of skin changes, risk factors, and medical background.
2. Examination: Careful inspection of the lesion and nearby lymph nodes.
3. Biopsy: Performed to confirm the diagnosis.
4. Referral: If MCC is confirmed, referral to a multidisciplinary cancer team for treatment planning.
5. Support: Guidance on sun protection, follow-up, and emotional wellbeing.

Reviewed by: Dr Mohammad Ghazavi, Consultant Dermatologist
Skinhorizon Clinic, 4 Clarendon Terrace, Maida Vale, London W9 1BZ
Last reviewed: 22 August 2025