A 68-year-old man presents with a painless, slowly enlarging nodule on his right cheek that has been present for 8 months. On examination, there is a 1.5 cm pearly nodule with a rolled border, central ulceration, and prominent telangiectasia. The patient has a history of prolonged sun exposure due to outdoor work. Dermoscopy reveals arborizing vessels. What is the most appropriate next step in management?

Explanation

## Diagnosis and Clinical Presentation **Key Point:** The clinical presentation is classic for basal cell carcinoma (BCC) — a pearly nodule with rolled borders, central ulceration (rodent ulcer), telangiectasia, and dermoscopic arborizing vessels in a sun-exposed area. ## Management Approach for BCC **High-Yield:** The standard diagnostic and therapeutic approach for a solitary BCC on the face is **excisional biopsy with adequate margins (3–5 mm) followed by histopathology**. This achieves both diagnosis confirmation and complete removal in one step. ### Why Excisional Biopsy? 1. **Diagnostic confirmation** — histology establishes BCC subtype (nodular, infiltrative, micronodular, basosquamous), which guides prognosis and follow-up. 2. **Therapeutic intent** — 3 mm margins are adequate for most low-risk BCCs; histology confirms complete excision. 3. **Cost-effective** — single procedure combining diagnosis and treatment. **Clinical Pearl:** Mohs micrographic surgery is reserved for: - High-risk subtypes (infiltrative, micronodular, basosquamous) - Recurrent BCC - Large tumors - Anatomically sensitive areas (periocular, nasolabial fold, ears) - This lesion does not meet high-risk criteria based on size and location. ## Comparison of BCC Treatment Modalities | Modality | Indication | Cure Rate | Limitations | |----------|-----------|-----------|-------------| | **Excisional biopsy** | Low-risk, solitary BCC | 95–98% | Requires suturing; leaves scar | | **Mohs surgery** | High-risk, recurrent, large | 99%+ | Expensive; requires specialized training | | **Imiquimod 5%** | Superficial BCC only | 80–90% | Prolonged course; poor for nodular/infiltrative | | **Cryotherapy** | Superficial BCC | 85–90% | Unpredictable depth; poor cosmesis | | **Observation** | Slow-growing, patient refusal | N/A | Risk of local invasion, metastasis (rare) | **Mnemonic: MOHS** — **M**ohs for **M**ultiple, **O**ld/recurrent, **H**igh-risk, **S**ensitive areas. **Warning:** Do not use topical imiquimod or cryotherapy for nodular BCC — these are only effective for superficial variants. This lesion has a rolled border and central ulceration, indicating nodular or infiltrative subtype. [cite:Robbins 10e Ch 25]