A case report of an infant with the clinical, radiological, and histological presentations of infantile cortical hyperostosis is presented. Besides the classically described subperiosteal thickening, the present patient radiographically also had well-circumscribed intramedullary lytic lesions in both proximal tibial metaphyses, which subsequently disappeared in 3 months. These lesions have not been previously described in the literature. Resolution of these lesions suggests they may be part of the radiological picture of infantile cortical hyperostosis and probably may be managed by observation.