REPORT OF A CASE
A 19-month-old boy with numerous nevi, including a 10-cm congenital nevus of the scalp, developed a pigmented left paraspinal plaque at the age of 10 months. There was hypertrichosis within the plaque, and the mother reported ''bulging'' when the area was stroked. A vertebral radiograph was normal. On physical examination, there was a 3×3-cm smooth, hyperpigmented plaque with hypertrichosis at approximately Level L2-4 in the left paraspinal region. (Figure 1 and Figure 2) Magnetic resonance imaging of the lumbar spine was normal.A skin biopsy specimen was obtained from the left paraspinal plaque (Figure 3 and Figure 4).What is your diagnosis?
Congenital smooth-muscle hamartoma.
The biopsy specimen demonstrated an unusual array of smooth-muscle bundles within the reticular dermis. These smooth-muscle bundles were well-defined and extended in various directions. Some of the smooth-muscle bundles within the reticular dermis.
Sahn EE, Grine RC. A Pigmented Paraspinal Plaque in an Infant. Arch Dermatol. 1995;131(5):614. doi:10.1001/archderm.1995.01690170117021