Casal et al. Journal of Medical Case Reports 2010, 4:386 http://www.jmedicalcasereports.com/content/4/1/386 C A S E R E P O R T JOURNAL OF MEDICAL CASE REPORTS Open Access A non-recurrent inferior laryngeal nerve in a man undergoing thyroidectomy: a case report Diogo Casal*, António Peças, Daniel Sousa, Jorge Rosa-Santos Abstract Introduction: A non-recurrent variant of the inferior laryngeal nerve has been seldom reported. These reports are mostly based on cadaveric dissection studies or large chart review studies in which the emphasis is placed on the determination of the frequency of the variation, and not on the clinical appearance of this variant. We graphically describe the intraoperative identification of a non-recurrent inferior laryngeal nerve. Case Presentation: A 44-year old Caucasian man was referred to the Head and Neck Surgery Outpatient Clinic with the diagnosis of a nodular mass in his left thyroid lobe that had been growing for one year. A fine needle aspiration puncture was compatible with thyroid papillary cancer. It was decided that the patient should undergo total thyroidectomy. During surgery, a non-recurrent right inferior laryngeal nerve was noted. This nerve emanated from the right vagus nerve, entering the larynx 3 cm after its origin. The nerve did not show a recurrent course. The nerve on the left side had a normal configuration. The surgery and post-operative period were uneventful, and the patient had no change in his voice. Conclusion: This paper allows those interested to become acquainted with the normal intraoperative appearance of a non-recurrent inferior laryngeal nerve. This will undoubtedly be of significance for all of those performing invasive diagnostic and surgical procedures in the neck and upper thoracic regions, in order to minimize the risk of iatrogenic injury to this nerve. This is of extreme importance, since a unilateral lesion of this nerve may result in permanent hoarseness, and a bilateral lesion may lead to aphonia and life-threatening dyspnea. Introduction The inferior laryngeal nerve (ILN) is traditionally named recurrent due to the fact that, branching off the vagus nerve, it usually describes a loop as it turns upwards, passing under the subclavian artery on the right and under the ligamentum arteriosum on the left [1]. The ILN provides innervation to all larynx intrinsic muscles, except for the cricothyroid muscle. From a sen- sorial point of view, it innervates the mucosal surface of the larynx below the vocal cords [2]. Injury to this nerve may thus result in paralysis of the vocal cord on the same side, leading to permanent hoarseness. If the lesion is bilateral, aphonia and life-threatening dyspnea may ensue as a result of medial placement of the paralytic vocal cords, which can obstruct the glottis [3]. The relatively long course of the inferior laryngeal nerves place them at risk of iatrogenic injury in * Correspondence: diogo_bogalhao@yahoo.co.uk Head and Neck Surgery Department, Instituto Português de Oncologia de Lisboa, R. Prof. Lima Basto, 1099-023 Lisbon, Portugal numerous procedures involving the cervical and upper thoracic regions [1]. Among these, surgical procedures in the cervical region, namely thyroidectomies, are parti- cularly common. In this last setting, for example, per- manent injury to the recurrent laryngeal nerve (ILN) is reported in 0.25 to 2.6% of cases, with rates >8% in case of reoperation [4]. It has been demonstrated that dissec- tion and visualization of the ILN during such proce- dures significantly reduces the risk of lesion to this nerve [5]. To accomplish this, it is instrumental to have a sound knowledge of the normal and variant forms of the ILN [6]. Case presentation A 44-year-old Caucasian man was referred to the Head and Neck Surgery Outpatient Clinic with the diagnosis of a nodular mass in his left thyroid lobe that had been growing since the previous year. His previous medical history was unremarkable. No other enlarged masses or lymph nodes were palpated in the physical examination © 2010 Casal et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.