Diagnosis: Merkel cell carcinoma
A 72-year-old male presents with a painless, solitary violaceous nodule on sun-damaged skin of the face, persisting for several months. The lesion's rapid growth and the patient's significant sun exposure raise suspicion for an aggressive cutaneous malignancy, warranting further evaluation.
A 72-year-old male with a history of significant sun exposure presents with a 3-month history of a painless, solitary violaceous nodule on his right cheek. On examination, the lesion measures approximately 2 cm in diameter, is firm, and exhibits a shiny surface. There is no evidence of ulceration or bleeding, and regional lymphadenopathy is absent.Location: Face, commonly on sun-exposed areas.Size: Typically ranges from 1-5 cm at presentation.Color: Violaceous or bluish hue, often with a smooth surface.Consistency: Firm to palpation, with no tenderness.Growth pattern: Rapidly enlarging, often noted over weeks to months.
The lesion began as a small bump that gradually enlarged over the past three months. The patient has a history of extensive sun exposure without prior skin cancers. He denies any previous skin lesions in this area or family history of skin malignancies. He is a retired construction worker and has not undergone any dermatologic procedures.Onset: Lesion started small, progressively enlarging over 3 months.Triggers: Significant sun exposure throughout life.Prior treatments: No treatments attempted prior to presentation.Past medical history: Hypertension and hyperlipidemia, well-controlled.Family history: Non-contributory for skin cancers.Social history: Retired construction worker, minimal sunscreen use.
Acute / First-Line ManagementComplete surgical excision is the primary treatment for localized Merkel cell carcinoma, aiming for clear margins. Mohs micrographic surgery is often preferred in cosmetically sensitive areas.Adjuvant radiation therapy may be considered post-surgery, especially in cases with high-risk features (e.g., lymphovascular invasion, large tumor size).For unresectable or metastatic cases, systemic therapy options include chemotherapy regimens such as cisplatin and etoposide.Workup and Diagnostic ConfirmationA biopsy (excisional or incisional) is essential for diagnosis, revealing characteristic small blue cells with scant cytoplasm.Immunohistochemical staining for CK20 (with a characteristic dot-like pattern) and CD56 supports the diagnosis.Staging workup may include imaging studies such as CT or PET scans to assess for regional or distant metastasis.Long-Term ManagementRegular follow-up with skin examinations is crucial, given the risk of local recurrence and metastasis.Consideration of adjuvant therapies based on risk stratification, including immunotherapy such as pembrolizumab or nivolumab for advanced disease.Patient education on sun protection and skin monitoring is vital for prevention of new skin cancers.
Basal Cell Carcinoma: Most common skin cancer; often presents as a pearly nodule with telangiectasia and may ulcerate.Squamous Cell Carcinoma: Can present as a crusted, non-healing lesion; often associated with actinic keratosis.Dermatofibroma: Firm, raised lesion, often brownish; typically mobile and may be tender.Melanoma: Asymmetrical, irregular borders, multiple colors; requires thorough evaluation due to aggressive nature.Kaposi Sarcoma: Vascular lesions often associated with immunosuppression; can be violaceous but typically more diffuse.Angiosarcoma: Rare, aggressive vascular tumor; presents as a bruise-like lesion and can be multifocal.Neuroendocrine Tumor: Rare, but can mimic Merkel cell carcinoma; requires histological confirmation.Seborrheic Keratosis: Benign growth; often has a warty surface and a stuck-on appearance.
High-Yield PearlsAEIOU criteria: Remember the mnemonic for Merkel cell carcinoma: Asymptomatic, Expanding, Immune suppression, Older than 50, Ultraviolet exposure.Risk factors: Significant UV exposure, immunosuppression, and older age increase risk for development.Diagnosis: Requires biopsy and immunohistochemical confirmation; CK20 positivity is a hallmark.Management: Surgical excision is first-line; adjuvant therapy may be indicated based on risk assessment.Surveillance: Lifelong follow-up is essential due to high recurrence and metastasis rates.Merkel cell carcinoma is a rare but aggressive skin cancer that demands prompt recognition and management to improve patient outcomes.
Tags: Merkel cell carcinoma, MCC