Extrafacial Merkel Cell Carcinoma Presenting as a Cyst

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin tumor.
• Typically presents in elderly white males with significant sun exposure history.
• Characterized by erythematous or violaceous nodules.

Observation:

• Presents two cases of extrafacial Merkel cell carcinoma.
• Lesions observed included a cystic nodule and a firm plaque.
• Highlights the importance of considering MCC in differential diagnoses for skin lesions.

Findings:

• Literature review identifies tools for earlier MCC diagnosis.
• Primary tumor location significantly impacts prognosis.
• An algorithm for diagnostic workup is provided.

Implications:

• Emphasizes the aggressive nature of MCC with high recurrence and metastasis risk.
• Early detection is imperative for improved patient outcomes.
• Highlights the need to include MCC in the differential diagnosis of suspicious skin nodules and cysts.