This is possibly an example of acute middle ear sepsis that resulted in mastoiditis, which perforated the petrus temporal allowing communication with the internal soft tissue structures. The individual is from St. Andrew’s Fishergate, a medieval cemetery in York   We would like to thank York Archaeological Trust for the opportunity to present these specimens.

Left temporal

An erosive lesion on the superior surface of the petrous temporal superiorly, which has sharp margins and measures c. 6.7mm x c. 2.9, penetrates to and exposes the middle ear cavity allowing for observation of the ear ossicles.   The malleus is fused to the anterosuperior roof of the middle ear cavity (red arrow).  Internally, there is pitting of the middle ear cavity with exposure of the mastoid air cells.  Further irregular lytic lesions are located in an arch at the lateral most part of the petrous temporal and the endocranial wall, some of which expose the underlying mastoid air cells.