Distribution of Psammoma Bodies in the Internal Auditory Canal and its Extended Areas in the Human Temporal Bone

Abstract

The internal auditory canal (IAC) and its extended areas of 27 normal human temporal bone specimens were investigated histologically for the distribution of psammoma bodies. A total of 145 ± 25 (mean ± SE) psammoma bodies were counted in series of every tenth 30-μm-thick section. Psammoma bodies were observed in the IAC and around the labyrinthine portion of the facial nerve (FN), the geniculate ganglion of the FN, and the posterior ampullary nerve in the singular canal. The number of psammoma bodies increases with age. We believe that psammoma bodies are a normal finding of aging in the IAC. The compression of the FN by psammoma bodies in the labyrinthine portion of the facial canal and the distribution of numerous psammoma bodies surrounding the posterior ampullary nerve in the narrow singular canal raise the questions of the involvement of psammoma bodies in the FN and in vestibular dysfunction and the presence of psammoma bodies in the subarachnoid space.