See also:
Overview
The superior cornu of the thyroid cartilage may project into the pharynx in a submucosal fashion - with this finding occasionally attributed to previous trauma (Avrahami 1994). Congenitally determined prominence to the superior cornu of the thyroid cartilage has been reported as a reason for its appearance without considering it pathological. The prominence of this structure seen as a normal variant in elderly patients has been further highlighted by Turkmen (2012) et al who identified that 'the human skeletal system, and particularly cartilage tissues, undergo significant changes with age".
Our experience with the incidental finding of prominence of the superior cornu in the pharynx is that it is commonly asymptomatic as the patient whose images below correlated with the absence of pharyngeal symptoms:
Asymmetry to the larynx is common as identified by Hirano (1989) through study demonstrating asymmetry in each of the 50 excised human larynges they studied. These investigators identified that a directional preponderance in adults (with the right thyroid lamina tilting laterally) was not seen in newborns where there was no directional preponderance.
Investigators have attributed symptoms of dysphagia, odynophagia, throat pain, foreign body sensation and crepitus to prominence of this anatomic structure into the the pharynx. Case reports address surgical removal by transoral route (Wojtowicz 2015) and discussion about external open approach (Nadig 2006).
Heuveling et al in 2018 (Heuveling 2018) identified successful surgical treatment of 'a clicking larynx' occuring on the right side during swallowing and associated with a sore throat. They offer a nice review of the literature identifying 16 previously reported cases with 12 receiving surgical treatment. Nicely illustrated diagrams and surgical photos identify their proposal that possible causes for 'clicking larynx' include: a short distance between hyoid bone and superior part of the thyroid cartilage; displaced superior cornu; enlarged greater horn of hyoid bone; and abnormal bone formation in the thyrohyoid ligament.
A good discussion about the variability in the hyo-laryngeal anatomy focussed on embryonic development is offered by de Bakker et al (de Bakker 2018).
Refererences
Turkmen S, Cansu A, Turedi S, Eryigit U, Sahin A, Gunduz A, Shavit I. Age-dependent structural and radiological changes in the larynx. Clin Radiol. 2012;67(11):e22-26
Smith ME, Berke GS, Gray SD, Dove H, Harnsberger R. Clicking in the throat: cinematic fiction or surgical fact? Arch Otolaryngol Head Neck Surg. 2001;127(9):1129-1131.
Avrahami E, Harel M, Englender M. CT evaluation of displaced superior cornu of ossified thyroid cartilage. Clin Radiol. 1994;49(10):683-685.
Nadig SK, Uppal S, Back GW, Coatesworth AP, Grace AR. Foreign body sensation in the throat due to displacement of the superior cornu of the thyroid cartilage: two cases and a literature review. J Laryngol Otol. 2006;120(7):608-609.
Piotr Wojtowicza, Tomasz Szafarowskia, b, Wojciech Kukwaa, Ewa Migacza, Antoni Krzeskia: Extended Superior Cornu of thyroid Cartilage Causing Dysphagia and Throat Pain. Journal of Medical Cases Vol 6, Number 3, March 2015, pages 134-6
Shiozawa T, Epe P, Herlan S, Müller M, Tropitzsch A, Tsiflikas I, Hirt B. Clinically relevant variations of the superior thyroid cornu. Surg Radiol Anat. 2017 Mar;39(3):299-306. doi: 10.1007/s00276-016-1735-5. Epub 2016 Aug 29.
Heuveling DA, van Loon MC, Rinkel RNPM: A Clicking Larynx: Diagnostic and Therapeutic Challenges. Laryngoscope 128:697-700, 2018
Hirano M, Kurita S, Yukizane K, Hibi S (1989) Asymmetry of the laryngeal framework: a morphologic study of cadaver larynges. Ann Otol Rhinol Laryngol 98:135–140
de bakker BS, de Bakker HM, Soerdjbalie-Maikoe V, and dikkers FG: The Development of hte Human Hyoid-Larynx Complex Revisited Laryngoscope, 128:1829-1834, 2018
