Cephalohematoma
Cephalohematoma presents as a localized mass that does not cross suture lines. It is usually unilateral and over the parietal bone. The blood collects between the external periosteum and the bone. The mass is firm, tense, and confined to an individual bone. The edge of the mass may feel like a ridge. Underlying linear fracture is detected in 10% to 25% of cases. Cephalohematoma is produced by forces that tend to separate the periosteum from the bone. Complications are hyperbilirubinemia, late onset anemia, and osteomyelitis. Cephalohematomas require no treatment. Complications should be treated accordingly.

Increased thickness of the skull can occur with osteopetrosis. Osteopetrosis is a disorder characterized by overgrowth of brittle bones. This results in thick, dense, and fragile bones. The bony tissue overgrowth results in encroachments of the: (1) bone marrow leading to anemia, (2) cranial nerves foramina leading to deafness, blindness, or other signs of cranial nerve dysfunction, (3) Pacchioni bodies producing communicating hydrocephalus and macrocephaly. Osteopetrosis may be an autosomal recessive or an autosomal dominant disorder but only the autosomal recessive form occurs during the neonatal period.
Neonates with osteopetrosis may present with hypocalcemic seizures. Hepatomegaly is not usually present in the neonatal period. Alkaline phosphatase is increased. This condition is diagnosed by obtaining whole-body radiographs. Radiographs show dense bones, anterior notching up the vertebral bodies, thick ribs, and a bone-within-bone appearance of the hands.