Patient History
Right pulsatile tinnitus.
Findings
Contrast-enhanced CT was performed from the skull base to the thoracic inlet. Study shows no evidence of aggressive lesions involving the nasopharynx, oral cavity, tongue base, tonsils, larynx or hypopharynx. No evidence of enlarged lymph nodes using standard size criteria.
There is asymmetric enlargement of the right common carotid artery. There is diffuse enlargement and tortuousity to the right external carotid artery which feeds a markedly enlarged and tortuous internal maxillary artery. There are diffusely enlarged vessels involving the right masticator space that extend into the right parotid space. Specifically, there are diffusely enlarged vessels involving the right pterygopalatine fossa that extend into the right pterygoid plexus and extending into the right parotid. This is associated with an enlarged right retromandibular vein draining into an enlarged right external jugular vein.
Visualized portion of the brain is grossly within normal limits. However, dedicated brain imaging is necessary for complete diagnostic evaluation.
Visualized portion of the lungs is grossly within normal limits. However, dedicated chest CT is necessary for complete diagnostic evaluation.
Conclusions
1. Findings most consistent with a right internal maxillary artery fistula resulting in dilatation of the right external carotid artery and dilatation of the draining vascular structures which include the pterygoid plexus, right retromandibular vein and right external jugular vein.
