A midline cyst containing clear fluid in an infant and review of management.

A 3-month-old healthy girl had a cyst present from birth, located in the midline, in the area of the anterior fontanel. A magnetic resonance imaging was performed at age 7 months, which did not show communication between the cyst and the central nervous system. At a subsequent examination, while the cyst was being probed, it broke and expressed clear fluid. The cyst was subsequently removed surgically and was found histopathologically to be an epidermal inclusion cyst without communication with the central nervous system. Epidermal inclusion cysts very rarely occur on the midline in the area of the anterior fontanel, and none have been reported to contain clear fluid. Their proper management requires focused clinical assessment, noninvasive imaging, and consideration of surgical removal, in particular, if they communicate with the intracranial space.