|Year : 2013 | Volume
| Issue : 3 | Page : 229-231
Papillary thyroid carcinoma arising from a thyroglossal duct cyst
Nasrollah Maleki1, Manouchehr I Alamdari1, Iraj Feizi2, Zahra Tavosi3
1 Department of Internal Medicine, Imam Khomeini Hospital, Ardabil University of Medical Sciences, Ardabil, Iran
2 Department of Cardiothoracic Surgery, Imam Khomeini Hospital, Ardabil University of Medical Sciences, Ardabil, Iran
3 Department of Internal Medicine, Shohadaye Khalije Fars Hospital, Bushehr University of Medical Sciences, Bushehr, Iran
|Date of Web Publication||28-Mar-2014|
Department of Internal Medicine, Iran- Ardabil- Imam Khomeini Hospital, Ardabil University of Medical Scinces, Ardabil-6368134497
Source of Support: None, Conflict of Interest: None
Thyroglossal duct cysts (TGDCs) are the most common form of congenital cysts on the neck. The incidence of papillary thyroid carcinoma in TGDC is less than 1%. In most cases, the diagnosis is made postoperatively. We present a case of 22-year-old female with papillary thyroid carcinoma arising from a TGDC, identified in pathologic study after Sistrunk operation. There was no clinical evidence of malignancy in the cyst. There was neither invasion to adjacent tissue nor lymph node involvement. The patient then underwent total thyroidectomy and bilateral neck dissection. The patient was treated with radioactive iodine and thyroid suppression therapy was given as adjuvant treatment. She has been followed-up for 2 years without any metastasis.
Because of the rarity of TGDC, this diagnosis may be missed, drastically affecting the appropriateness of the treatment provided. Surgeons should be aware of TGDC in surgical planning and postoperative treatment and should include this pathology in differential diagnosis of anterior midline neck masses.
Keywords: Papillary thyroid carcinoma, thyroidectomy, TGDC
|How to cite this article:|
Maleki N, Alamdari MI, Feizi I, Tavosi Z. Papillary thyroid carcinoma arising from a thyroglossal duct cyst. Arch Int Surg 2013;3:229-31
| Introduction|| |
Thyroglossal duct cysts (TGDCs) are one of the most common (75%) asymptomatic midline congenital neck masses in childhood. , In general, duct cysts are benign, but about 1% of cases are malignant.  The majority of patients present within the first 2 decades of life, but nearly a third of cases may manifest in young adulthood.  TGDC carcinoma may be clinically indistinguishable from benign TGDC, and the diagnosis in most cases is incidental after surgical resection. The use of fine needle aspiration cytology (FNAC) under ultrasound guidance may enhance the preoperative diagnosis. In case of malignancy, clinicians usually consider a Sistrunk operation and a thyroidectomy. In this report, we present a female adult with a papillary carcinoma of the TGDC that was diagnosed histologically after Sistrunk operation.
| Case Report|| |
A 22-year-old woman presented with a painless midline neck swelling which had been progressively increasing in size for 6 months. There was no history of dysphagia, hoarseness, or fever. There was a painless cystic mass about 3.0 × 1.5 cm at mid-cervical line which moves with swallowing, without cervical nodes enlargement. The thyroid gland was normal. Routine blood analyses and thyroid function tests were normal. Ultrasonography of the neck showed a well-defined, cystic mass (23 × 18 × 12 mm in size) with an echogenic component (7 × 7 mm in size) [Figure 1]. A diagnosis of thyroglossal cyst was made. The patient underwent Sistrunk operation. The cyst was adherent to the hyoid bone. On gross examination, the cyst measured 3 × 2 × 1.5 cm in size and was attached to the hyoid bone. Microscopic examination revealed a cystic neoplasm composed of slender arborizing papillae with hyalinized fibrovascular cores lined by cuboidal cells, with nuclear crowding and overlapping, indicating a papillary thyroid carcinoma [Figure 2]. Total thyroidectomy and bilateral neck dissection were performed. The final postoperative pathology reported papillary carcinoma without any metastasis to the thyroid and cervical lymph nodes. One hundred mCi I 131 radioactive iodine and 200 mcg/day levothyroxine was given after the operation. One month after surgery, thyroid function tests and radioiodine scanning revealed no abnormalities. Six months, 1 year and 2 years after surgery, repeat I 131 thyroid scanning revealed no abnormality and thyroglobulin serum level was also normal.
|Figure 2: Histology of the thyroglossal duct cyst demonstrating papillary thyroid cancer|
Click here to view
| Discussion|| |
TGDCs develop from persistence of the mid portion of the thyroglossal duct which is an embryonic structure that traces the path of the descent of the thyroid gland. The duct is normally obliterated at the 8th-10th week of gestation, but if it fails to involute completely, the remaining epithelial tissue can develop a TGDC. Previous studies have suggested that this failure to involute occurs in approximately 7% of the population. 
Brentano in 1911 and Uchermann in 1915 are among the first researchers to describe a neoplasm in a thyroglossal duct remnant. A review of the literature showed that 250 cases of malignant thyroglossal cysts have been reported.  It occurs more commonly in women and is seen in the infrahyoid region along the course of the thyroglossal duct. The most common histological pattern is of papillary carcinoma of the thyroid.  The percentages of different types of neoplasia in reported cases of TGDCs are: Papillary carcinoma 81.7%; mixed papillary-follicular carcinoma 6.9%; squamous cell carcinoma 5.2%; follicular and adenocarcinoma, 1.7% each; and malignant struma, epidermoid carcinoma and anaplastic carcinoma, 0.9% each.  Benign TGDCs usually present as asymptomatic, soft, firm, or hard masses in the midline of the anterior neck, and are non-tender and generally movable. As shown in our patient malignant TGDCs present in the same manner. Carcinoma should be suspected when the cyst is hard, fixed, and irregular or has undergone recent change. A history of irradiation of the head and neck or mediastinum during childhood or adolescence should also arouse suspicion of carcinoma. 
To confirm a diagnosis of TGDC, the following criteria should be fulfilled: the cyst must be located in the median region of the neck; its wall must consist of cuboidal epithelial cells and lymphatic tissues and normal thyroid follicles must be present in the cystic wall.  On ultrasonography, a benign TGDC can be anechoic, homogenously hypoechoic, homogenously hyperechoic, or heterogenous in appearance. Calcification is the hallmark of papillary carcinoma in a TGDC.  In our case, apart from the cystic lesion, ultrasonography showed an echogenous component without calcification.
Pre-operative thyroid scan, ultrasound-guided FNAC (US-FNAC) and computed tomography (CT) or magnetic resonance imaging (MRI) imaging of the neck are gaining popularity to enhance the accuracy of preoperative diagnosis. , Although, preoperative thyroid scans confirm the presence of ectopic thyroid tissue in 33% of TGDC, such scans have not been beneficial in the preoperative diagnoses of carcinoma.  US-FNAC though simple, rapid, inexpensive with minimal risk of complications is more reliable in diagnosing solid tumors rather than cystic lesions. Additionally, FNAC is not cost-effective due to the rarity of this malignancy and remains an inappropriate tool for routine use in children. , CT or MRI imaging of the neck is rarely indicated preoperatively unless there is a high clinical or FNAC suspicion of malignancy. , Imaging features such as a solid nodule with calcification or thick wall are suggestive of malignancy. , Ogawa et al., have suggested a possible utilization of three-dimensional CT in providing accurate pre-operative diagnosis of papillary thyroid carcinoma in a TGDC. 
The diagnosis, however, is often made postoperatively on pathological examination of the resected specimen. The common surgical procedure used for a TGDC is Sistrunk procedure. In case of malignancy, additional steps should consist of thyroidectomy, radioactive iodine, and thyroid suppression.  Our patient had no nodules in the thyroid gland, no previous exposure to radiation, no lymph node metastasis, and no extracapsular spread of the TGDC carcinoma. She needs further life-long follow-up with physical examinations and imaging studies.
| Conclusion|| |
The diagnosis of TGDC may be missed because of its rarity. Surgeons should be aware of TGDC in surgical planning and postoperative treatment and should include this pathology in differential diagnosis of anterior midline neck mass. When TGDC carcinoma is suspected pre-operatively, meticulous high-resolution ultrasonography of the thyroid and neck should be performed. When features suggestive of TGDC are found, US-FNAC is recommended. If there are suspicious lesions in the thyroid or lymph node, Sistrunk operation with total thyroidectomy, and lymph node dissection should be performed.
| References|| |
|1.||Dan D, Rambally R, Naraynsingh V, Maharaj R, Seetharaman H. A Case of malignancy in a thyroglossal duct cyst-recommendations for Management. J Natl Med Assoc 2012;104:211-4. |
|2.||Kermani W, Belcadhi M, Abdelkefi M, Bouzouita K. Papillary carcinoma arising in a thyroglossal duct cyst: Case report and discussion of management modalities. Eur Arch Otorhinolaryngol 2008;265:233-6. |
|3.||Weiss SD, Orlich CC. Primary papillary carcinoma of thyroglossal duct cyst report of a case and review literature. Br J Surg 1992;79:1248-9. |
|4.||Telander RL, Deane SA. Thyroglossal and branchial cleft cysts and sinuses. Surg Clin North Am 1977;57:779-91. |
|5.||Ellis PD, van Nostrand AW. The applied anatomy of thyroglossal tract remnants. Laryngoscope 1977;87:765-70. |
|6.||Geok Chin T, Mohd Sidik SH, Manickam S, Seng Phang K, Clarence-Ko CH, Jeevanan J. Papillary carcinoma of the thyroglossal duct cyst in a 15-year-old girl. Int J Otorhinolaryngol 2007;2:732-5. |
|7.||Reede DL, Bergeron RT, Som PM. CT of thyroglossal duct cysts. Radiology 1985;157:121-5. |
|8.||Peretz A, Leiberman E, Kapelushnik J, Hershkovitz E. Thyroglossal duct carcinoma in children: Case presentation and review of the literature. Thyroid 2004;14:777-85. |
|9.||Roses DF, Snively SL, Phelps RG, Cohen N, Blum M. Carcinoma of the thyroglossal duct. Am J Surg 1983;145:266-9. |
|10.||Taori K, Rohatgi S, Mahore DM, Dubey J, Saini T. Papillary carcinoma in a thyroglossal duct cyst: A case report and review of literature. Indian J Radiol Imaging 2005;15:531-3. |
|11.||Torcivia A, Polliand C, Ziol M, Dufour F, Champault G, Barrat C. Papillary carcinoma of the thyroglossal duct cyst: Report of two cases. Rom J Morphol Embryol 2010;519:775-7. |
|12.||LaRouere MJ, Drake AF, Baker SR, Righter HJ, Magielski JE. Evaluation and management of a carcinoma arising in a thyroglossal duct cyst. Am J Otolaryngol 1987;8:351-5. |
|13.||Yang YJ, Haghir S, Wanamaker JR, Powers CN. Diagnosis of papillary carcinoma in a thyroglossal duct cyst by fine needle aspiration biopsy. Arch Pathol Lab Med 2000;124:139-42. |
|14.||Plaza CP, Lopez ME, Carrasco CE, Meseguer LM, Perucho AF. Management of well-differentiated thyroglossal remnant thyroid carcinoma: Time to close the debate? Report of five new cases and proposal of definitive algorithm for treatment. Annal Surg Oncol 2006;13:745-2. |
|15.||Motamed M, McGlashan JA. Thyroglossal duct carcinoma. Curr Opin Otolaryngol Head Neck Surg 2004;12:106-9. |
|16.||Ogawa C, Kammori M, Onose H. Utilization of three-dimensional computed tomography for papillary thyroid carcinoma arising in the thyroglossal duct remnant: Report of a case. Surg Today 2010;40:650-3. |
[Figure 1], [Figure 2]