Are You Confident of the Diagnosis?
What you should be alert for in the history
The diagnosis of thyroglossal duct cyst (TDC) is based on the presence of an asymptomatic midline neck mass, usually in a child. It may also present as an infected neck mass in the setting of an upper respiratory infection.
Characteristic findings on physical examination
Characteristic findings on physical examination include a midline lesion that moves upward, with swallowing and with tongue protrusion. This maneuver may not result in upward movement in cases where embryologic anlage from the foramen cecum on the base of the tongue is no longer present.
Expected results of diagnostic studies
The most common diagnostic studies are ultrasound and computed tomography (CT). Ultrasound will reveal a midline cystic structure that approximates the hyoid bone. CT is also commonly used to define extent of lesion and relationship to the surrounding anatomic structures (Figure 1). Biopsy is usually not necessary.
Ultrasound confirms the normal anatomic position of the thyroid to rule out ectopic thyroid tissue.
Other cystic lesions in the differential diagnosis include brachial cleft cysts (which are located laterally on the neck) and bronchogenic cysts (usually located in the suprasternal notch).
Who is at Risk for Developing this Disease?
TDC typically affects children (75%), but may also be seen in adults.
What is the Cause of the Disease?
The etiology of TDC is remnant tissue from the tract formed during the normal migration of thyroid tissue from the base of the tongue to the lower neck.
The pathophysiology of TDC is the failure of cells of the thyroglossal tract to involute.
Systemic Implications and Complications
A midline neck mass can rarely be ectopic thyroid tissue, so an ultrasound is helpful to confirm the normal anatomic location of the thyroid and avoid possible removal of the patient’s only functioning thyroid tissue.
There are no associated congenital abnormalities.
Definitive treatment is surgery to completely excise the lesion.
If the cyst is infected, it should be treated with antibiotics to cover typical head and neck flora prior to surgical treatment.
Optimal Therapeutic Approach for this Disease
Surgical excision is the treatment of choice. An infected cyst should be treated with antibiotics prior to resection. The surgical treatment is an outpatient procedure, performed under general anesthesia, in which the cyst and a portion of the hyoid bone are removed via a small incision on the neck (Sistrunk procedure).
Recurrence is rare after appropriate surgical excision, and would present as a midline neck cyst. Surgical re-excision is performed for confirmed recurrence to remove residual ductal tissue.
There is no need for routine monitoring postoperatively.
Surgical risk is minimal. Complications include hematoma, seroma, wound infection, abscess, and recurrence.
Unusual Clinical Scenarios to Consider in Patient Management
While most cysts are typically midline, they may also be just off center. Imaging with CT or magnetic resonance imaging will differentiate these from other congenital cystic anomalies in the neck.
Although almost all thyroglossal duct cysts are benign, other primary malignancies have been found in resected specimens. These include thyroid cancer, with papillary thyroid cancer being the most common type encountered.
There is controversy is about the necessary extent of surgical treatment of lesions revealing papillary thyroid cancer. While some advocate total thyroidectomy, others believe no further surgery is warranted. There are also reports of squamous cell cancer being found in resected specimens.
What is the Evidence?
Sistrunk, WE. “The surgical treatment of cysts of the thyroglossal tract”. Ann Surg. vol. 71. 1920. pp. 121-6. (Article by Dr. Sistrunk highlighting embryology, diagnosis, and treatment of thyroglossal duct cysts)
Wagner, G, Medina, J. “Excision of thyroglossal duct cyst: the Sistrunk procedure”. Operative Technique in Otolaryngology. vol. 15. 2004. pp. 220-3. (Detailed surgical review of the Sistrunk procedure, including step-by-step pictures)
Marianowski, R, Ait Amer, JL. “Risk factors for thyroglossal duct remnants after Sistrunk procedure in a pediatric population”. Int J of Pediatr Otorhinolaryngol. vol. 67. 2003. pp. 19-23. (Retrospective chart review done to highlight the most common risk factors for cyst recurrence. These include the number of infections prior to surgery, prior surgical procedure, age less than 2, and a multicystic lesion.)
Maddalozzo, J, Venkatesan, TK, Gupta, P. “Complications associated with the Sistrunk procedure”. The Laryngoscope. vol. 111. 2001. pp. 119-23. (Reviews rates of postoperative complications in the pediatric population undergoing the Sistrunk procedure)
Dedivitis, R, Camargo, D, Peixoto, G. “Thyroglossal duct: a review of 55 cases”. J Am Coll Surg. vol. 194. 2002. pp. 247-77. (Single institution review of the diagnosis and treatment of thyroglossal duct cysts)
Gupta, P, Maddalozzo, J. “Preoperative sonography in presumed thyroglossal duct cysts”. Arch Otolaryngol Head Neck Surg. vol. 127. 2001. pp. 200-2. (Single institution review of preoperative ultrasonography to confirm normal thyroid anatomy and avoid inadvertent removal of ectopic thyroid tissue)
Pribitkin, E, Friedman, O. “Papillary carcinoma in a thyroglossal duct remnant”. Arch Otolaryngol Head Neck Surg. vol. 128. 2002. pp. 461-2. (Reviews the pros and cons of total thyroidectomy in patients diagnosed with papillary thyroid cancer after thyroglossal duct excision)
Myssiorek, D. “Total thyroidectomy is overly aggressive treatment for papillary carcinoma in a thyroglossal duct cyst”. Arch Otolaryngol Head Neck Surg. vol. 128. 2002. pp. 464(Reviews rationale for not performing a total thyroidectomy in patients found to have thyroid cancer in resected thyroglossal duct cyst specimen)
Persky, M. “Total thyroidectomy as appropriate treatment for papillary carcinoma in a thyroglossal duct cyst”. Arch Otolaryngol Head Neck Surg. vol. 128. 2002. pp. 463(Rationale for performing total thyroidectomy in patients found to have thyroid cancer in resected thyroglossal duct cyst specimen)
Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.
No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.