In simple words: Merkel cell carcinoma is a rare type of skin cancer that grows quickly. It often appears as a painless lump on the skin, which may be skin-colored or reddish-blue. It's more common in older people with fair skin and weakened immune systems. It's important to get any new or changing skin lumps checked by a doctor.

Merkel cell carcinoma (MCC), also known as neuroendocrine carcinoma of the skin or trabecular cancer, is a rare and aggressive malignancy arising from Merkel cells in the epidermis. It typically presents as a painless, rapidly growing nodule, often skin-colored, red, blue, or purplish-red, primarily on sun-exposed skin like the face, head, neck, arms, legs, and trunk. Individuals with fair skin, weakened immune systems, and those over 50 are at higher risk. MCC can metastasize quickly to regional lymph nodes and distant organs.

Example 1: A 70-year-old male with a history of sun exposure presents with a rapidly growing, painless, red nodule on his forehead. Biopsy confirms Merkel cell carcinoma., A 60-year-old female with a compromised immune system develops a flesh-colored lump on her arm.Following excision and sentinel node biopsy, she is diagnosed with Stage II Merkel cell carcinoma., A 55-year-old male with a history of MCC undergoes a PET scan which reveals metastases in the liver, indicating Stage IV disease. He receives chemotherapy and immunotherapy.

Documentation should include the location, size, and appearance of the lesion, biopsy results confirming MCC diagnosis, imaging reports, treatment plan, and follow-up notes regarding treatment response and any recurrence.