Excision of Lingual Thyroid
Excision of Lingual Thyroid is a surgical procedure to remove Lingual Thyroid which is an abnormal mass of ectopic thyroid tissue seen in base of tongue.
Some facts about Excision of Lingual Thyroid:
- The approach for excision of Lingual Thyroid is oral, transhyoid, and lateral pharyngotomy.
- Lingual thyroid can be a cause of embryological aberrancy in development of thyroid gland.
- Lingual thyroid gland is a rare clinical entity which can be found at the base of the tongue and represents the most common location of functioning ectopic thyroid tissue.
- Dysphagia, choking, hemorrhage, and dyspnea and occasionally life-threatening airway obstruction may be experienced by patients with lingual thyroid tissue.
- Malignant transformation of the lingual thyroid can also happen.
- Thyroxine replacement should be introduced as initial therapy, for patients with obstructive symptoms to induce glandular shrinkage.
- Surgical removal is necessary if conservative treatment fails.
- Thyroid scintigraphy with Technetium 99 (99mTc) and neck ultrasound can be performed to diagnose lingual Thyroid.
- Magnetic resonance imaging can help in defining the extension and location of the ectopic thyroid gland
Procedure for Lingual Thyroid:
- Transoral, transmandibular, and lateral pharyngotomy are the three main approaches to surgical excision of lingual thyroid.
- Increased morbidity and prolonged hospitalization is needed for open surgery.
- CO2 laser, electrocautery assisted resection with rigid endoscope and operating microscope and suspension laryngoscopy can be performed although the approaches are limited by safe visibility and difficulty in manipulation rendering resection more difficult.
- The lingual thyroid can be accessed through a cervicotomy incision in the neck in the lateral pharyngotomy approach.
- Although important anatomical obstacles such as the lingual artery, hypoglossal nerve, superficial laryngeal nerve, and the superior thyroid artery are countered, this technique is mandible-sparing.
- Development of pharyngocutaneous fistula formation and skin scar are the risk associated with this approach.
- Transoral robotic surgery (TORS) is a feasible minimally invasive approach for excision of the lingual thyroid. It is a safe with larger three-dimensional point of view and easier manipulation due to freedom of motion of robotic instruments.
- Lingual artery injury can be a risk with transoral robotic lingual thyroid resection which can be prevented by preoperative imaging methods and careful dissection with knowledge of anatomy.
- A wide exposure of tongue in the transmandibular approach for excision of lingual thyroid and thus, the need for a tracheostomy can be reduced.
- Lip split mandibulotomy, dissection of mylohyoid muscles to reach the base of the tongue and exposure of lingual mass is involved in this approach.
- The osteotomized mandible is plated with primary closure of superficial layers after the tumor is dissected out and excised.
- Lip hypoesthesia, facial disfigurement, malocclusion of teeth, and temporomandibular joint pain are the risks associated with the transmandibular approach.
- An alternative to surgery is Thyroid ablation with radioactive iodine and is usually reserved for unfit patients or those who refuse surgical intervention.
- Llingual thyroid can be excised and autotransplanted to the muscles of neck in patients lacking thyroid tissue in the neck.
- Lifelong exogenous thyroid hormone replacement is required regardless of the surgical approach.
