title: An unreported variation of the cervical vagus nerve: anatomical and histological observations.
abstract: Variations involving the cervical portion of the vagus nerve are seemingly very rare. We report an adult male found to harbour a right cervical vagus nerve that crossed anterior to the right common carotid artery to terminate in the lateral aspect of the thyroid gland. A very small continuation of this nerve was found to continue distally into the thorax. Histologically, this part of the vagus nerve did not contain ganglion or other cell bodies. There were no heterologous inclusions (thyroid, parathyroid, thymus, salivary gland or branchial cleft remnants) present. Although grossly there was a connection into the thyroid gland, this was not observed histologically. No signs of trauma were found to the ipsilateral neck region. We hypothesise that this variation is due to entanglement between the thyroid gland and cervical vagus nerve during development. This rare variation might be considered by the clinician who operates in the cervical region or interprets imaging of the neck. To our knowledge, a vagus nerve with the above described morphology has not been described.
authors.affiliation: Department of Cell Biology, University of Alabama at Birmingham, and Department of Pathology and Laboratory Medicine, Children's Hospital, Birmingham, AL 35233, USA. rstubbs@uab.edu
authors.forename: R S
authors.initials: RS
authors.lastname: Tubbs
authors.forename: M
authors.initials: M
authors.lastname: Loukas
authors.forename: M M
authors.initials: MM
authors.lastname: Shoja
authors.forename: D
authors.initials: D
authors.lastname: Blevins
authors.forename: R
authors.initials: R
authors.lastname: Humphrey
authors.forename: G D
authors.initials: GD
authors.lastname: Chua
authors.forename: D R
authors.initials: DR
authors.lastname: Kelly
authors.forename: W J
authors.initials: WJ
authors.lastname: Oakes
mesh_terms: D000368:Aged; D017536:Carotid Artery, Common / Q000002:abnormalities; D002465:Cell Movement; D003238:Connective Tissue / Q000002:abnormalities; D005726:Ganglia, Parasympathetic / Q000002:abnormalities; D006801:Humans; D008297:Male; D009333:Neck / Q000002:abnormalities*; D009412:Nerve Fibers / Q000473:pathology / Q000648:ultrastructure; D038081:Organogenesis; D012009:Recurrent Laryngeal Nerve / Q000002:abnormalities; D013961:Thyroid Gland / Q000002:abnormalities* / Q000294:innervation; D014630:Vagus Nerve / Q000002:abnormalities* / Q000166:cytology / Q000473:pathology