## Why Mohs micrographic surgery is right The lesion is located on the nose, which is part of the H zone (central face — high-risk anatomical location for BCC). The pearly translucent rolled border marked **A** is the classic morphologic hallmark of nodular BCC, the most common subtype. For BCCs in high-risk facial locations (nose, eyelids, lips, ears), Mohs micrographic surgery is the gold standard because it provides 100% margin assessment with real-time histopathologic control, allowing maximum tissue preservation while achieving recurrence rates < 1% compared to 10% with standard excision. This is particularly important on the nose, where cosmetic and functional outcomes are critical (Robbins 10e Ch 25; Harrison 21e Ch 75). ## Why each distractor is wrong - **Standard excision with 4 mm margins**: While appropriate for low-risk lesions (≤ 2 cm on trunk, < 1 cm on head/neck with well-defined borders), standard excision is suboptimal for facial BCCs in the H zone. It lacks real-time margin assessment and has higher recurrence rates (10%) on the face. - **Curettage and electrodesiccation alone**: This destructive technique is reserved for small, low-risk lesions on the trunk or extremities. It is inadequate for facial BCCs and provides no histopathologic margin control, risking incomplete treatment and recurrence. - **Topical imiquimod 5% cream**: Topical immunomodulators are indicated only for superficial BCC (erythematous patches on trunk mimicking eczema), not for nodular BCC with a rolled border. This lesion requires surgical intervention. **High-Yield:** BCC on the face (H zone) = Mohs surgery; BCC on trunk/extremities, low-risk = standard excision or destruction. [cite:Robbins 10e Ch 25; Harrison 21e Ch 75]
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