Cutaneous Malignancies and Soft Tissue Lesions of the Head and Neck
Core concepts
Know basal cell carcinoma subtypes, squamous cell carcinoma risk factors and perineural invasion, melanoma Breslow depth and sentinel node indications, and benign lesions (epidermoid cyst, pilomatrixoma, pyogenic granuloma). Understand Mohs indications and margin principles.
Traps in questions
- Assuming all basal cell carcinomas are low risk; morpheaform and recurrent lesions need wider margins or Mohs.
- Forgetting that perineural invasion in cutaneous SCC worsens prognosis and may warrant radiation.
- Mismatching melanoma sentinel node biopsy thresholds to Breslow depth.
- Confusing pyogenic granuloma with amelanotic melanoma clinically.
Rule of thumb
On the face, high-risk features (recurrent, morpheaform, perineural, large size) push toward Mohs or wider excision.
Worked example
A recurrent basal cell carcinoma on the nasal ala has ill-defined borders. The question asks the best treatment. The rule: recurrent and cosmetically sensitive sites favor Mohs micrographic surgery for margin control and tissue conservation. Simple excision with standard margins risks positive margins and recurrence.