The petrous segment of the Internal Carotid Artery (pICA) runs within the carotid canal in the temporal bone, surrounded by functional structures that are underknown by neurosurgeons. Although the ICA, lying in its bony canal, is well protected in its petrous segment, it remains exposed to dissection and other pathological entities like infections, radiation and congenital malformations that could lead to the formation of aneurysms [1], [2], [3].

In the international English literature, only few case reports of extracranial ICA aneurysms – ie. affecting its cervical or petrous segments – are available. When symptomatic, petrous aneurysms usually present with neurological or oto-rhinological signs due to mass effect or hemorrhage [4], [5], [6]. The ear, nose and throat (ENT) presentation can be characterized by abrupt massive epistaxis/otorrhagia [4] or chronic symptoms such as hearing loss. The latter presentation is rarer and thus constitutes a particularly challenging diagnostic issue, as emphasized by the case here reported along with the literature review.

The present study is about the rare and unusual clinical presentation of a patient suffering from direct compression of the Eustachian Tube (ET) by a pICA aneurysm, hence revealed by middle ear chronic otitis. We performed a literature review according to the PRISMA statement in order to identify all cases of analogous presentation to depict common as well as peculiar features [7].

Such a rare and unusual presentation appears particularly relevant to neurosurgeons as it points out the need for a thorough understanding of anatomical structures surrounding the pICA. Particularly, the authors would like to emphasize how ET and pICA course side-by-side, as this counterintuitive fact might guide the understanding of all clinical manifestations as well as the management strategy of this rare pathology.