Cephalohematoma

History: A 7-week-old female with left scalp hard swelling, rule out hematoma

Skull X-Ray: Frontal and lateral projection.

Definition

The cephalohematoma represents subperiosteal hemorrhage. The periosteum of the involved bone, usually parietal or occipital bone, is elevated by the underlying hematoma. Therefore, the hematoma is sharply limited by the margins of the bone and does not cross suture lines. In its earliest stages (first two weeks), the hematoma is of soft tissue density due to its blood contents. Early skull films (during the first two weeks) will show the swelling as a soft tissue "mass" which is limited at its margins by the cranial sutures.

As healing progresses, there is formation of a shell of bone by the elevated periosteum and the calcification becomes visible radiographically, as in this case. It initially appears as a thin calcified shell at approximately two weeks, covering the hematoma, and the layer of calcification subsequently thickens as it matures. The later sequelae, following complete resorption of hematoma, result in incorporation of the calcified rim into the outer table of the skull. This may persist for months or years as a palpable (and radiographically visible) thickening of the outer table of the skull.

Subtle skull fractures underlying the cephalohematoma may coexist but are usually not clinically significant.

Causes

The usual causes of a cephalohematoma are a prolonged second stage of labor or instrumental delivery, particularly ventouse.

Symptoms

If severe the child may develop jaundice, anemia or hypotension. In some cases it may be an indication of a linear skull fracture or be at risk of an infection leading to osteomyelitis or meningitis.

The swelling of a cephalohematoma takes weeks to resolve as the blood clot is slowly absorbed from the periphery towards the centre. In time the swelling hardens (calcification) leaving a relatively softer center so that it appears as a depressed fracture.

Cephalohematoma should be distinguished from another scalp bleeding called subgaleal hemorrhage (also called subaponeurotic hemorrhage), which is blood between the scalp and skull bone (above the periosteum) and is more extensive. It is more prone to complications, especially anemia and bruising.

Management

No laboratory studies usually are necessary. Vitamin C has been reported to hurry the resorption of hematoma. Skull X-ray or CT scanning is used if neurological symptoms appear. Usual management is mainly observation. Transfusion and phototherapy may be necessary if blood accumulation is significant. Aspiration is more likely to increase the risk of infection. The presence of a bleeding disorder should be considered. Skull radiography or CT scanning is also used if concomitant depressed skull fracture is a possibility.

Differential Diagnosis

In the neonate, swelling of the scalp may also be seen with caput succedaneum (subcutaneous edema and/or hemorrhage) and subgaleal hemorrhage (subaponeurotic hemorrhage). These two conditions are more superficial and extend more widely over the skull because they are not limited by the attachments of the periosteum.

In the older infant and child, sequelae of cephalohematoma may cause confusion. Asymmetry of the skull or palpable bulge at the site of the calcified cephalohematoma may cause clinical concern for a skull mass or craniosynostosis. Skull radiography will usually demonstrate the characteristic smooth thickening resulting from an old calcified cephalohematoma. The findings may persist for years, even into adulthood. A cyst-like radiolucent lesion at the site of old cephalohematoma may also persist, and this entity should be kept in mind when evaluating cyst-like skull lesions.

Sushila Ladumor, MD, FRCR, Consultant Radiologist with Multi-modality Imaging experience, working in Medical Imaging Department, King Abdulaziz Medical City, Riyadh, Saudi Arabia. 

References:

http://www.pedsradiology.com/Historyanswer.aspx?qid=59&fid=1http://en.wikipedia.org/wiki/File:Scalp_hematomashttp://www.fpnotebook.com/nicu/neuro/Cphlhmtm.htm