Photo Rounds

Irregular macule on back

A 60-year-old man presented to his family physician (FP) for his yearly physical exam. Since the patient had a basal cell carcinoma on his face 2 years earlier, his FP had been doing a complete skin exam as part of the patient’s yearly preventive care visit. The patient was otherwise in good health with a good diet and a regular exercise regimen. While performing the skin exam, the FP noted an irregular macule on the patient’s back. The patient was not aware of this spot, but admitted that he did not typically check his back in the mirror.

What’s your diagnosis?


 

Irregular macule on back

The FP suspected that this could be a melanoma and took out his dermatoscope. (See “Dermoscopy in family medicine: A primer.”) The FP was initially concerned about melanoma because the lesion appeared chaotic, with multiple colors and an irregular border. Going through the ABCDE criteria, he noted that the macule was Asymmetric, the Border was irregular, the Colors were varied, the Diameter was >6 mm, but the history was insufficient to say whether it was Enlarging. Of course, 4 out of 5 positive criteria requires a tissue diagnosis.

Dermoscopy added evidence for regression in the center and an atypical network in the brown and black areas. The FP performed a deep shave biopsy (saucerization) with 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, which was adequate for a lesion of this type. The pathology report confirmed melanoma in situ.

On a return visit, the FP performed a local wide excision with 5 mm margins down to the deep fat. The surgical specimen revealed only the scar at the biopsy site with no remaining cancer. This reassured the patient because it should provide a cure very near 100%. The FP provided counseling about sun protection and the need for regular skin exams.

Photos 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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