A seven days old male neonate was routinely assessed in our newborn nursery. The baby was born at 38 weeks by vaginal delivery after an uncomplicated pregnancy. He is the firstborn child of non‐consanguineous parents of African descent. The baby was noticed to have a dimple on both shoulders which were present since birth. Each dimple was 2 mm deep and was located bilaterally on the acromion. There were no other skin changes around the dimple. There was no restriction in range of movement at the shoulder joint. No other lesions were noted and rest of the exam was normal. The baby’s father was also noted to have similar bilateral acromial dimples without any complication.
Biacromial dimples have been previously reported in pediatric literature. They seem to have an autosomal dominant inheritance pattern. This is also validated in our patient. Review of the literature suggests that, these dimples arise due to the entrapment of skin between the shoulder bones and wall of the uterus. These dimples are found infrequently, and are a solitary finding in most 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. In this case, the baby did not exhibit any of the characteristic features of 18q deletion syndrome such as hypotonia; malformations of the hands and feet; or abnormalities of the craniofacial region like microcephaly, a “carp‐shaped” mouth, deeply set eyes, prominent ears, and/or mid‐facial hypoplasia. A case report in 2006 reported an association of subacromial dimples with recurrent posterior positional (atraumatic) dislocation of the shoulder. It was also suggested that instability was common in glenoid dysplasia which is a consistent finding in Apert’s syndrome.
Biacromial dimples should be considered as an anatomic variation without pathologic significance and do not warrant any further investigation. However, this case report signifies that it may be worthwhile for a clinician to know the associated etiologies when dealing with this curious anatomic variation.