Sympathetic Plexus Schwannoma of Carotid Canal: 2 Cases with Surgical Technique and Review of Literature

Carotid Sympathetic Plexus Schwannoma Presenting as Middle Ear and External Auditory Canal Mass

“…Three arose from the cavernous sinus part of the carotid canal, 8,10 and the other 3 cases arose from the petrous apex of the carotid canal. 9,12 The tumors in previous cases extended intracanially. The present case arose from the petrous portion of the carotid canal and extended to the middle ear, mastoid, and EAC.…”

“…The plexus also distributes to the pupillary dilator muscle and superior tarsal muscles. 9 Therefore, Horner's syndrome (miosis, anisocoria, ptosis, and anhidrosis) can be a complication after surgical excision of a sympathetic schwannoma. 10 Lesions around the ICA do not usually affect facial sweating because it is innervated through the external carotid plexus.…”

Review of the external carotid plexus: anatomy, function, and clinical manifestations

“…The pterygopalatine fossa receives its sympathetic input through the external carotid plexus, combined with the internal carotid plexus, the vidian nerve, and the plexus of the maxillary nerve [ 13 ]. Additionally, the external carotid plexus is involved in innervating facial sweat glands [ 14 ]. Previous research suggest that the external carotid plexus innervates sweat glands on the lateral side of the forehead, whereas the internal carotid plexus innervates the medial forehead’s sweat glands [ 15 ].…”

“…Carotid sympathetic plexus schwannoma, benign brain tumors, are rare and have been documented in only three cases [ 14 ]. In these three cases, the schwannoma was present in either the cavernous sinus part of the plexus or the petrous part of the carotid canal [ 14 ]. Therefore, these schwannomas typically arise from the internal carotid nerve [ 14 ].…”

“…In these three cases, the schwannoma was present in either the cavernous sinus part of the plexus or the petrous part of the carotid canal [ 14 ]. Therefore, these schwannomas typically arise from the internal carotid nerve [ 14 ]. Removal of the schwannoma from the cavernous plexus also resulted in partial Horner syndrome [ 14 ].…”