A 29-year-old man comes to the physician for a routine preventive examination. He is currently feeling well but states that he has always had "some dark spots" on his back. The patient has no family history of heart disease or cancer. He does not spend much time outdoors and had no prior sunburn. He does not smoke. Physical examination shows many pigmented lesions on his back as shown below. The following 8-mm lesion is seen on close skin inspection.
Which of the following is the best next step in the management of this patient's skin lesion?

Question

A 29-year-old man comes to the physician for a routine preventive examination.  He is currently feeling well but states that he has always had "some dark spots" on his back.  The patient has no family history of heart disease or cancer.  He does not spend much time outdoors and had no prior sunburn.  He does not smoke.  Physical examination shows many pigmented lesions on his back as shown below.  The following 8-mm lesion is seen on close skin inspection.
 Which of the following is the best next step in the management of this patient's skin lesion?

Quizplus · Accepted Answer

Explanation: This pigmented lesion has an increased risk of melanoma based on size (>6 mm in diameter). It also has mild border irregularity. Definitive diagnosis with biopsy should be considered for any suspicious pigmented skin lesion. Excisional biopsy with an elliptical or punch biopsy technique is indicated and should include the entire lesion with 1-3 mm margins of the surrounding skin and underlying subcutaneous fat. Patients with confirmed melanoma will require additional resection and staging procedures in most cases. (Choice A) Acanthosis nigricans is characterized by abnormal pigmentation of flexural areas and is often associated with insulin resistance. Atypical nevi and melanoma do not correlate with insulin resistance. Acanthosis nigricans (Choice C) Incisional biopsy (only a portion of the lesion is removed) is not generally recommended for melanoma. However, it does not appear to adversely affect prognosis compared to excisional biopsy. It may be considered for unusually large tumors or for locations where cosmetic results are important (eg, the face). (Choice D) Periodic surveillance (with or without photographic documentation) is appropriate for patients at elevated risk for melanoma (eg, personal or family history of melanoma, multiple atypical nevi). However, this patient has a suspicious lesion which should be evaluated first with an excisional biopsy. (Choice E) Sentinel lymph node biopsy and lymphatic mapping is indicated for patients with confirmed melanoma who do not have clinical evidence of lymph node involvement but are at increased risk (eg, tumor thickness >0.75 mm, tumor ulceration, evidence of lymphatic invasion on biopsy). Educational objective: Patients with skin lesions suspicious for melanoma should have excisional biopsy to include the entire lesion with 1-3 mm margins of the surrounding skin and subcutaneous fat. References: Incisional biopsy and melanoma prognosis: Facts and controversies. (http://www.ncbi.nlm.nih.gov/pubmed/20541685)

A 29-Year-Old Man Comes to the Physician for a Routine