Bi-acromial Dimples: A sign of beauty?

Background: Bi-acromial dimples, also known as “supraspinous fossae” or shoulder dimples are an anatomic peculiarity that should be considered an anatomic variation. They seem to have an autosomal dominant inheritance pattern. These dimples are thought to result from the entrapment of skin between the shoulder bones and the wall of the uterus. They can also appear in other parts of the body and coexist in the same individual. These dimples are found infrequently, and are solitary findings in the majority of the cases. However, bi-acromial dimples have been reported as part of malformation syndromes such as 18q deletion syndrome, and skeletal dysplasias such as Apert’s syndrome.

Objective: Raise awareness amongst pediatricians for anatomic variations in the skin and its benign nature.

Case Presentation: A 2-year-old boy with no previous medical history presented at his regular pediatric consultation for his annual follow-up. The parents have noticed he had a dimple on both his shoulders which made them worried that was pathologic. There was no family history of these kind of dimples that was known to them. On physical examination deep dimples were present in the acromial region bilaterally and symmetrically, 10mm in diameter, about 5 to 10mm deep and without dermal or hypodermic atrophy. No other somatic abnormalities were found. There was also no restriction in range of movement of the shoulder joints.

Conclusion: Bi-acromial dimples may be considered an anatomic curiosity. However, it is important that pediatricians are aware of this entity in order to reassure parents of its benign nature. It is of special interest to look for this abnormality in several generations, but familial observations are not necessarily associated with a genetic syndrome. In this case bi-acromial dimples were an isolated anatomical peculiarity, with no known familial occurrences. Skin dimples were discovered incidentally and are most probably underdiagnosed.