A 72-year-old woman from Mumbai presents with a 2 cm indurated, flesh-colored plaque with a depressed center on the right temple. She reports the lesion has been present for 2 years and has not changed significantly. On dermoscopy, multiple telangiectatic vessels are seen without pigmentation. She has a history of multiple similar lesions treated with cryotherapy over the past decade. Which treatment modality would be most appropriate for this lesion, considering its clinical behavior and location?

Explanation

## Clinical Context: Infiltrative BCC with Recurrent History ### Patient Profile and Risk Factors **Key Point:** This patient presents with features suggestive of **infiltrative basal cell carcinoma (BCC)** with a high recurrence risk: - **Age:** 72 years (cumulative UV exposure) - **Location:** Temple (high-risk anatomical site) - **Morphology:** Indurated, flesh-colored plaque with depressed center (infiltrative pattern) - **History:** Multiple BCCs treated previously (suggests field cancerization and genetic predisposition) - **Duration:** 2 years without significant change (typical slow growth of BCC) ### Why Mohs Micrographic Surgery is Optimal | Factor | Significance | Implication | |--------|-------------|-------------| | **Infiltrative subtype** | Ill-defined borders, aggressive growth pattern | High recurrence with standard excision (10–15%) | | **Recurrent lesion** | Previous treatment history | Risk of subclinical extension | | **Facial location** | Cosmetically sensitive, high-risk site | Need for tissue preservation + clear margins | | **Mohs advantage** | Real-time histological margin assessment with 100% margin evaluation | Highest cure rate (95–99%) | | **Standard excision** | Assumes 4–6 mm clinical margin; misses subclinical disease in infiltrative BCC | Inadequate for this case | **High-Yield:** Mohs micrographic surgery is the gold standard for: 1. Infiltrative or morpheaform BCC 2. Recurrent BCC 3. Large lesions (>2 cm) 4. Lesions in cosmetically sensitive areas (face, eyelid, ear, nose) 5. Lesions with poorly defined borders This patient meets ALL five criteria. ### Why Other Options Are Suboptimal **Topical imiquimod 5% cream:** - Indicated for **superficial BCC** only (not infiltrative) - Requires 6–12 weeks of daily application - Efficacy 80–90% (lower than Mohs) - Not suitable for thick, indurated lesions - Would be inadequate for this 2 cm infiltrative lesion **Observation alone:** - BCC has potential for local invasion and tissue destruction - Although metastasis is rare, continued growth can damage underlying structures (bone, cartilage, nerve) - Passive observation is not standard of care for a confirmed or highly suspected BCC **Systemic chemotherapy:** - Reserved for **metastatic BCC** (extremely rare, <0.1% of cases) - Not indicated for localized disease - This patient has no evidence of metastasis ### Treatment Algorithm for BCC ```mermaid flowchart TD A[BCC Diagnosis]:::outcome --> B{Subtype & Risk Factors?}:::decision B -->|Superficial, small, low-risk| C[Topical agents or cryotherapy]:::action B -->|Nodular, small, low-risk| D[Excision with 4-6 mm margins]:::action B -->|Infiltrative, recurrent, large, or facial| E[Mohs Micrographic Surgery]:::action B -->|Metastatic or unresectable| F[Systemic therapy: vismodegib, sonidegib]:::action E --> G[Highest cure rate 95-99%]:::outcome D --> H[Cure rate 90-95%]:::outcome C --> I[Cure rate 80-90%]:::outcome ``` **Clinical Pearl:** Mohs surgery is not just about cure rate—it maximizes tissue preservation, which is critical on the face where cosmesis and function are paramount. For a 72-year-old with a 2 cm infiltrative lesion on the temple, Mohs is the standard of care.