As for my openion , the cause for cephalhematoma is birh trauma, (apart from instrumental)meaning, the trauma caused by the very process of labor, when the fetus undergoes moulding and descent into the pelvic cavity during the various events of labor mechanism, even in spontaneous vaginal delivery. Every fetus passing through pelvis, is proned for this.This happens most frequently in first born children. Most of them undergo spontaneous resolution.
In the great majority of cases, cephalhematoma most probably commences during birth, and increases to a palpable tumor soon afterwards. But instances do occur, in which the swelling is not perceptible till several days after birth; and there is nothing against the opinion, that it may form on the skull subsequently to the birth of the child. Its duration may extend over three or four months, or more..
ICD 9 code 920, 767.19 are the more appropriate codes for a recent one/on going event.
At a later date: late effect codes like 677, V codes like 13.7, V29.1; if was instrumental 958.8, 669.5 can be given a look.
Some may persist long due to calcification even infection, form sepsis or abcess.
What is the presenting symptom/sign?
We have to know what is the reason for encounter-Presenting symptoms,signs, sequlae, at this time to the OV- may be it is indurated, infected or calcified or any other neurological / intracranial manifestations. This has to be given priority and first listed.
If no symptom or sign associated with cephalhematoma, this can be only a secondary diagnosis or Vcode (History of code).
But if they had come for follow up like concern, cosmetic purposes, with out active symptoms, follow up codes are also to be assigned
Follow up should be considered for cases below 2years of age since the cranium continues to grow and there appears to be a chance for spontaneous resolution. Diagnostic x ray , CT / MRI may be needed.
Given rarity of calcified cephalhematoma(CH), it is difficult to withdraw any conclusion regarding their clinical management. Nevethless, follow up for asymptomatic calcified CHs for atleast a few months in the hope that they could disappear spontaneously with out any cosmetic problem.