A 52-year-old man from Mumbai presents with a 1.2 cm dark brown nodule on his left shoulder that has been present for 3 months. Dermoscopy shows asymmetry, irregular borders, and mixed colors (brown, black, and red). There is no ulceration or bleeding. No regional lymphadenopathy is palpable. What is the most appropriate next step in management?

Explanation

## Clinical Assessment This patient presents with a clinically suspicious melanoma based on ABCDE criteria (Asymmetry, irregular Border, Color variation, Diameter >6 mm, Evolving). The next step is tissue diagnosis via excisional biopsy. ## Management Algorithm for Suspected Melanoma ```mermaid flowchart TD A[Clinically suspicious pigmented lesion]:::outcome --> B{Diagnosis confirmed?}:::decision B -->|No| C[Excisional biopsy with narrow margins]:::action C --> D[Histopathology: Breslow thickness, mitotic rate, ulceration]:::outcome D --> E{Breslow thickness & stage?}:::decision E -->|≤1 mm, no ulceration| F[Wide local excision 1 cm margin]:::action E -->|1-4 mm or high-risk features| G[Wide local excision 2 cm margin + SLNB consideration]:::action E -->|>4 mm or stage III/IV| H[Wide local excision 2-3 cm + SLNB + staging]:::action ``` ## Key Point: **Excisional biopsy is the gold standard for diagnosis of suspected melanoma.** It must include the full thickness of the lesion (dermis) and a narrow margin (2 mm) of normal skin to allow accurate histopathological assessment of Breslow thickness, mitotic rate, ulceration, and Clark level — all critical prognostic factors. ## High-Yield: - **Excisional biopsy** is diagnostic AND therapeutic for lesions <2 cm - Histopathology determines Breslow thickness, which is the **single most important prognostic factor** in melanoma - Sentinel lymph node biopsy (SLNB) is indicated AFTER diagnosis and staging, not before - Staging investigations (CT/PET) are reserved for stage IB or higher (Breslow >1 mm with ulceration, or ≥2 mm) ## Clinical Pearl: **Do not delay tissue diagnosis with imaging.** Systemic staging is performed only after histological confirmation and risk stratification based on Breslow thickness. ## Mnemonic: **ABCDE of melanoma** — Asymmetry, Border irregularity, Color variation, Diameter >6 mm, Evolving (changing).