Atypical localized Mongolian spots in dark pigmented skin - a challenge for forensic medical examination

The assessment of skin changes in the context of possible child abuse is an important task in forensic medicine. This requires knowledge of pigmentation variants and pigmentation disorders such as congenital dermal melanocytosis, which includes Mongolian spots. Particularly in the case of atypical localization and dark pigmented skin, the differentiation from hematomas can be challenging. A case of two Nigerian siblings with extensive and atypically localized Mongolian spots is reported. The 1.5-year-old girl showed Mongolian spots on her back and the right side of her trunk. The 8-year-old boy showed Mongolian spots only on the back of his thighs. The authors are not aware of any case in which so called Mongolian spots were present exclusively on the back of the thighs and this case is all the more noteworthy as the back of the thigh is a common localization of blunt force trauma.