Endocrine Abstracts

The most feared nerve injury when treating thyroid cancer is that of the recurrent laryngeal nerve. However, there are other nerve complications, underestimated and underpublished, such as the lesion of the mandibular branch of the facial nerve, which requires a multiprofessional approach to recover functionality and esthetics, both affected.

Clinical Case: A 44 year old woman, under study for anemia, underwent a cervical ultrasound that showed in the left thyroid lobe a nodule with lobulated edges and poorly defined, iso-hypoechoic, with micro and macrocalcifications inside and peripheral vascularization of 21 mm and an adjacent adenopathy to the ipsilateral submandibular gland (level II), with microcalcifications and minimal vascularization of 16 mm. The FNA of the thyroid nodule was category VI of the Bethesda Classification and the thyroglobulin in aspirate of the adenopathy was 34.65 ng/ml. With these findings, total thyroidectomy + bilateral central lymphadenectomy and functional left lateral cervical lymphadenectomy of compartments II, III, IV and V were performed. Intraoperative neuromonitoring of both vagus and recurrent laryngeal nerves showed a superimposable signal pre and post-surgery and intraoperative PTH determination showed a decrease of 77.87% with a final PTH of 15.2 pg/ml, so that, according to our protocol, calcium and vitamin D supplementation was not required. In the post-anesthetic recovery room, facial asymmetry was observed with deviation and descent of the left labial commissure, which persisted 24 hours later, when she was discharged. The patient was referred to the speech therapist for assessment and myofunctional rehabilitative treatment.

Discussion: Injury to the mandibular branch of the facial nerve in lateral lymphadenectomy occurs when compartment II of the neck is approached. The lesion can be produced by different mechanisms: mechanical (the most frequent), thermal or chemical. To try to avoid injuring this nerve branch, it is recommended to be careful in the traction and compression with the retractors when approaching the lympho-fatty tissue of compartment II. Although it is a less described complication than spinal nerve injury, it significantly affects esthetics and oral functionality and interferes with the patients’ quality of life. For this reason, in the patient’s informed consent process for a lateral lymphadenectomy, it should be mentioned as a possible complication that, although it is generally transitory, can affect the patient’s social and working life.