
The parents of a healthy 20-month-old boy ask for advice about a birthmark on his lower back. The lesion is asymptomatic and has grown proportionately with their son. What's the diagnosis?

The parents of a healthy 20-month-old boy ask for advice about a birthmark on his lower back. The lesion is asymptomatic and has grown proportionately with their son. What's the diagnosis?

Published: June 4th 2020 | Updated: