Hyperostosis frontalis interna: case report and review of literature

Hyperostosis frontalis interna (HFI) has been reported in high frequency among post-menopausal elderly women. Although it was widely discussed in the past, this entity is rarely mentioned in the current pathology literature. We report a postmortem case of a 56 yr-old post-menopausal woman with irregular thickening of the internal surface of the frontal bone. Histology revealed an organized trabecular pattern with overall thickening of the cancellous bone. The periosteum and cortical bone were unaffected. The finding was considered to be unrelated to her death. HFI should be recognized as a benign entity and distinguished from other disorders that involve the frontal skull bone, such as Paget's disease, acromegaly, and malignancy. The etiology of HFI is unknown, but current hypotheses implicate hormonal stimulation.