Photo Rounds

Dark spot on arm

A 52-year-old Hispanic man presented to his family physician (FP) with a one-year history of a growing dark spot on his left arm. The man worked outdoors doing construction work. His borderline diabetes was under control. The dark lesion was 1.5 cm in diameter.

What’s your diagnosis?


 

Dark spot on arm

The FP suspected that this was a melanoma or a pigmented basal cell carcinoma.

Going through the ABCDE criteria, the FP noted that the spot was Asymmetric, the Border was irregular, the Colors were varied, the Diameter was >6 mm, and the history was positive for an Enlarging lesion. With 5 out of the 5 criteria positive, it was likely that this was a melanoma. The FP performed a deep shave biopsy (saucerization) with 1- to 2-mm margins to provide full sampling for the pathologist. (See the Watch & Learn video on “Shave biopsy.”) The depth of the tissue biopsy was approximately 1 to 1.5 mm (a dime is 1.4 mm in depth), which was adequate for a lesion of this type. The pathology report came back as invasive melanoma with a 0.25 mm Breslow depth.

The FP referred the patient to a local dermatologist, who agreed to see the patient within the next 2 weeks rather than the standard 3- to 4-month wait time for a new patient. The dermatologist performed a wide local excision with a 1-cm margin down to the fascia. While this melanoma was invasive, this depth did not require sentinel lymph node biopsy for staging. On a follow-up visit, the FP counseled the patient about sun protection and the need for regular skin exams. Note that while brown skin and regular sun exposure may be less risky for melanoma than fair skin with multiple sunburns, anyone can get a melanoma.

Photo courtesy of Eric Kraus, MD and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Karnes J, Usatine R. Melanoma. In: Usatine R, Smith M, Mayeaux EJ, et al. Color Atlas and Synopsis of Family Medicine. 3rd ed. New York, NY: McGraw-Hill; 2019:1112-1123.

To learn more about the newest 3rd edition of the Color Atlas and Synopsis of Family Medicine, see: https://www.amazon.com/Color-Atlas-Synopsis-Family-Medicine/dp/1259862046/

You can get the Color Atlas of Family Medicine app by clicking on this link: usatinemedia.com

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