Scalp hematomas commonly occur either following a perinatal injury at delivery or as part of head trauma.
Pathology
There are three types of hematoma, which are defined by their location within the scalp, in particular, their location as related to the galea aponeurosis and skull periosteum (this mnemonic is helpful when remembering the layers of the scalp). From superficial to deep, the three types are:
caput succedaneum: subcutaneous hematoma superficial to the galea aponeurosis, most commonly secondary to vacuum-assisted delivery
subgaleal hematoma: hematoma within the potential space between the galea aponeurosis and the skull periosteum
cephalohematoma: subperiosteal and therefore bound by the suture line