Background: The parietal and frontal bones are rarely affected in infantile cortical hyperostosis.
Case reports: Case n. 1: A 14-day-old boy developed a swelling of the left eyelid that extended to the face in a few days. It was tender and associated with fever. Laboratory findings were increased (RBC sedimentation rate and other signs of inflammation). CT scan of the sinuses, soft tissues and bones was normal, but at the age of 23 days minimal patches of rarefaction were seen on X-rays of the frontal bones. These lacunar areas gradually extended, with the inflammation persisted. A new CT scan at 6 months of age confirmed the existence of lacunar areas in the skull, but failed to find any lesions of the mandibles or nasal bones. At that time, scintigraphy showed inflammatory lesions of the skull and ribs. All clinical, laboratory and radiological findings spontaneously disappeared within 3 years. Case n. 2: Similar swellings of the face developed at the age of 15 days in the brother of case n. 1. The laboratory findings were identical to those for his brother, and there were minimal lytic areas of the vault of skull without any other lesions. At 3 months of age, X-rays confirmed the existence of skull lesions and showed cortical hyperostosis of the left humerus. Similar cortical hyperostosis of nasal bones appeared at the age of 8 months, while the inflammatory syndrome persisted. All findings gradually and spontaneously disappeared within 18 months.
Conclusions: Cortical hyperostosis are usually most prominent in the lower extremities in cases of familial infantile cortical hyperostosis. The lesions were largely confined to the skull in our cases, with no lesions of the mandible. The disease was only identified in the first case after a protracted course with unpredictable remissions and relapses and the discovery of the cortical hyperostosis in his brother.