Menu Healthy Lifestyle Diseases & Conditions First Aid Symptoms Tests & Procedures Videos Definitions FAQs Mongolian spotUpdated: 2017-06-13OverviewA mongolian spot is a large, blue-gray birthmark that's sometimes mistaken for a bruise. It's most common in darker skinned babies, especially those of Asian heritage.SymptomsMongolian spots usually appear on the lower back and, less commonly, on the buttocks, legs, or arms.TreatmentsThe birthmark tends to fade during childhood and requires no treatment. © 1998-2022 Mayo Foundation for Medical Education and Research(MFMER). All rights reserved. Terms of Use