A newborn girl presenting with a posterior neck mass and swelling of the hands could indicate which condition?

The presentation of a posterior neck mass and swelling of the hands in a newborn girl is suggestive of Turner's syndrome. This condition is characterized by the presence of a partial or complete absence of one of the X chromosomes in females, leading to various physical manifestations.

The posterior neck mass, often referred to as a cystic hygroma, is a common finding in Turner's syndrome. It occurs due to developmental anomalies in the lymphatic system and can be detected through imaging before or after birth. Additionally, swelling of the hands (lymphedema) is also noted in Turner's syndrome, further linking these clinical features to this condition.

Infants with Turner's syndrome may also present with short stature, webbed neck, and coarctation of the aorta, among other complications, which can be evaluated as they grow. Recognizing these clinical features in a newborn is crucial for early diagnosis and management of potential associated health issues.