Pronounced hyperostosis frontalis interna and co-occurring lesions in the skull base suggestive of a pituitary tumor in a woman from medieval Germany

Hyperostosis frontalis interna (HFI) is an osseous overgrowth characterized by symmetrical, irregular bone apposition on the internal table of the frontal bone, which preferentially occurs in females. In 1719, Morgagni described the condition as one sign of a triad comprising HFI, hirsutism, and obesity (Morgagni's syndrome). The etiopathogenesis of HFI is largely unresolved, but the condition is frequently associated with metabolic, endocrine, and neuropsychiatric disorders. In archaeological cases, which rely solely on dry bone diagnosis, the cause of HFI generally remains unknown, as is also the case regarding accompanying signs and symptoms. Here, we report a case of pronounced HFI in the skeleton of an old-adult woman from medieval Hildesheim dating to the 8th to 11th century CE. In addition to HFI, the cranium exhibits resorptive lesions of the sella turcica with dehiscence of the roof of the sphenoid sinus. The co-occurrence of these lesions suggests an underlying common cause for them. On the basis of differential diagnosis, we consider a functioning pituitary neuroendocrine tumor (PitNET) as the most likely common cause for the two conditions.