Photo Rounds

Large dark discoloration on the back

A family physician (FP) delivered a baby girl with a large dark discoloration on her back and multiple light brown spots on her arms. The infant’s Apgar scores were 9 and 10, and the remainder of the physical exam was normal. In particular, the neurologic exam was normal.

What’s your diagnosis?


The FP recognized that this child had a large bathing trunk nevus with multiple small melanocytic satellite lesions on her arms.

He explained to the worried parents that their daughter had a bathing trunk nevus and that a local expert was needed. The FP consulted a local dermatologist, who subsequently explained to the parents that there was a significant risk of cutaneous melanoma if nothing was done about this large congenital nevus. The dermatologist indicated that while removal could decrease that risk, the process would require multiple large surgeries by a plastic surgeon. She also explained that a magnetic resonance imaging scan of the brain would be needed at about 6 months to look for neurocutaneous melanosis, which can cause seizures, hydrocephalus, and a central nervous system melanoma.

The parents were conflicted about whether to put their child through a series of massive surgeries or to accept the higher risk of melanoma and proceed with careful monitoring by the dermatologist. ( No additional details on how this case resolved are available—Editor. )

Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Smith, M. Congenital nevi. In: Usatine R, Smith M, Mayeaux EJ, et al. Color Atlas of Family Medicine . 2nd ed. New York, NY: McGraw-Hill; 2013:953-957.

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