C4A.11

Clinical Causes: Exposure to ultraviolet (UV) radiation from sunlight or tanning beds Immunosuppression, such as in organ transplant recipients or individuals with HIV/AIDS Age, with increased risk in older adults Presence of Merkel cell polyomavirus, which has been linked to many cases of this cancer History of other skin cancers or skin damage Fair skin, light hair, and blue or green eyes, which are more susceptible to skin damage Multiple or atypical moles

Key Symptoms: A rapidly growing, firm, shiny or flesh-colored or bluish-red nodule on the eyelid or surrounding skin A lesion that may be mistaken for a benign cyst or skin growth Diameter larger than 1 centimeter at the time of diagnosis Ulceration or bleeding in the affected area A non-healing sore or wound Swelling or enlargement of nearby lymph nodes Possible discomfort or itching, though typically painless

Diagnosis Path: Physical examination of the lesion and nearby lymph nodes Dermatoscopy—magnified examination of the skin surface Biopsy—removal of a tissue sample for microscopic evaluation Imaging tests such as ultrasound, CT scans, MRI, or PET scans to assess the extent and spread Sentinel lymph node biopsy to determine if cancer has spread to lymph nodes

Treatment Protocols: Surgical excision—removal of the tumor with clear margins Mohs micrographic surgery—layer-by-layer removal with microscopic examination to preserve healthy tissue Radiation therapy—used after surgery to destroy remaining cancer cells or as the main treatment in inoperable cases Chemotherapy—systemic treatment for advanced stages or metastatic disease Immunotherapy—recent advances include immune checkpoint inhibitors that activate the body's immune response against cancer Clinical trials—exploring new therapies for Merkel cell carcinoma