A 62-year-old farmer from rural Rajasthan presents with a 2 cm erythematous, scaly nodule on the dorsum of his left hand with central ulceration and raised rolled edges. He reports a 6-month history of progressive growth. Dermoscopy shows hyperkeratosis and abnormal vasculature. Biopsy confirms well-differentiated squamous cell carcinoma (SCC) with no perineural invasion. The lesion is clinically confined to the skin without regional lymph node involvement. What is the most appropriate next step in management?

Explanation

## Management of Low-Risk Cutaneous SCC ### Lesion Risk Stratification **Key Point:** Risk classification determines surgical margins and reconstruction strategy. This patient's lesion is **low-risk** based on: - Well-differentiated histology - Absence of perineural invasion - Small size (< 2 cm) - Non-high-risk anatomical site (dorsal hand is lower-risk than ear, lip, or perioral) - No regional lymphadenopathy ### Surgical Approach for Low-Risk SCC | Feature | Low-Risk SCC | High-Risk SCC | |---------|-------------|---------------| | **Recommended margins** | 4–6 mm | 6–10 mm or Mohs | | **Histology** | Well-differentiated | Poorly differentiated, spindle cell | | **Perineural invasion** | Absent | Present | | **Surgical technique** | Conventional excision ± frozen section | Mohs micrographic surgery | | **Lymph node assessment** | Clinical exam only | Consider sentinel node biopsy | **High-Yield:** Wide local excision (WLE) with **4–6 mm margins** is the standard of care for low-risk, small SCC in non-critical sites. Intraoperative frozen section confirmation of clear margins reduces recurrence risk. ### Why Mohs Surgery Is Not Indicated Here **Clinical Pearl:** Mohs micrographic surgery is reserved for: - Poorly differentiated or high-grade tumours - Lesions with perineural invasion - Recurrent SCC - Lesions in critical anatomical zones (face, ear, eyelid, lips) - Immunocompromised patients - Large or ill-defined lesions This patient does not meet these criteria. ### Why Other Options Are Suboptimal **Warning:** Topical 5-FU is NOT a primary treatment for invasive SCC; it is used only for actinic keratosis or superficial non-invasive lesions (Bowen's disease). Observation without treatment is inappropriate for confirmed invasive SCC, as it carries risk of local progression and metastasis. [cite:Robbins 10e Ch 25]