A 16-year-old healthy white male adolescent presented with an asymptomatic swelling behind his ear. The lump was superimposed on what was thought to be a congenital nevus that had been present since birth. His family history and medical history were noncontributory.
Physical examination revealed a large brown-black hyperpigmented plaque involving the posterior aspect of the neck and extending up to the mastoid and occipital region of the scalp (Figure 1). The plaque was of varying thickness, being macular on the inferior portion and spongy and infiltrative near the superior and mastoid portions. This variation in thickness was a continuous, gradual change. The lesion also demonstrated some variation in pigment and moderate hypertrichosis. A diffuse spongy nodule behind the ear was more palpable than the rest of the plaque (but not visible on the photograph). No other lesions were found. Two punch biopsy specimens were obtained: one from the thick, spongy area behind the ear and the other from the proximal area of the occipital region of the scalp, which was macular and thin and resembled the majority of the plaque (Figure 2 and Figure 3). Neither specimen was obtained from an area that was particularly dark.
Mar WA, Bangert J, Hansen RC. Enlarging Congenital Pigmented Plaque—Quiz Case. Arch Dermatol. 2004;140(6):751. doi:10.1001/archderm.140.6.751-a