This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Skin
A 25-year-old female complains of a mole on her upper back. The lesion is 6 mm in diameter, darkly pigmented, and asymmetric, with a very irregular border. The next step in management is: 
Select and explain. 
A. Tell the patient to avoid sunlight, B. Follow the lesion for any evidence of growth, C. Obtain metastatic workup, D. Obtain full-thickness excisional biopsy
D: Obtain full-thickness excisional biopsy
Answer: D: Obtain full-thickness excisional biopsy 
Explanation: Ans. D. Obtain full-thickness excisional biopsya. The lesion has characteristics of melanoma (pigmentation, asymmetry, irregular border), and a full-thickness excisional biopsy is required. Shave biopsy of a suspected melanoma is always contraindicated.b. Diagnosis is urgent; the lesion cannot be observed over time. Once the diagnosis of melanoma is made, the tumor must then be staged to determine prognosis and treatment.