Contents lists available at ScienceDirect

J Ped Surg Case Reports 10 (2016) 3e6

Journal of Pediatric Surgery CASE REPORTS

journal homepage: www.jpscasereports .com

Sublingual thyroglossal duct cyst (SLTGDC): An unusual location

Sailesh Mukul*, Amit Kumar, Ejaz MokhtarAll India Institute of Medical Sciences (AIIMS) Patna, India

a r t i c l e i n f o

Article history:Received 23 December 2015Received in revised form11 April 2016Accepted 13 April 2016

Key words:Sublingual thyroglossal duct cystFine needle aspiration cytologySistrunk surgery

* Corresponding author.E-mail address: dr.saileshmukul@yahoo.co.in (S. M

2213-5766/� 2016 The Authors. Published by Elsevierhttp://dx.doi.org/10.1016/j.epsc.2016.04.010

a b s t r a c t

Thyroglossal duct cyst is the most common cause of midline congenital swelling in the neck. Classically, itpresents as an asymptomatic midline swelling below the hyoid bone that moves with deglutination andprotrusion of the tongue. Sometimes thyroglossal duct cyst presents atypical posing a diagnostic chal-lenge. A sublingual location of thyroglossal duct cyst is rare, and differs quite remarkably in presentationfrom the classical thyroglossal duct cyst. We describe here the case of a young boy who presented withepisodes of postural dyspnea due to elevation of the tongue which was secondary to huge sublingualswelling. Surgical decompression of the lesion was planned on an emergency basis with feasiblepreoperative workup. The aim of this case report is to highlight the unique presentation and a variedapproach in the management of an unusually located sublingual thyroglossal duct cyst. Sublingual/intralingual thyroglossal duct cyst needs to be analyzed in a larger study population for establishingdefinitive management protocols.� 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND

license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Thyroglossal duct cyst is the commonest cause of a midlineneck masses in children [1]. Approximately 7% of the populationhas thyroglossal duct remnants which account for 70% ofcongenital neck abnormalities [2]. Thyroglossal duct cyst presentsbefore the age of 6-years in 76% of cases [3]. It has also beendetected in the fetus in utero [4]. In 85% of cases the thyroglossalduct cyst is found below the hyoid bone [5]. However, it may besituated anywhere between the foramen cecum and the supra-sternal notch.

The sublingual location of thyroglossal duct cyst with itsinferior boundary located around mylohyoid region was a diag-nostic challenge until it was histopathologically established.Thyroglossal duct cyst (TGDC) is usually diagnosed clinically.Classically the cyst moves upward on protrusion of the tonguewhich is path gnomic. Ultrasonography is the preferred imagingtechnique in children. Here we report the case of a young boywith an atypical presentation of sublingual thyroglossal cyst. Hepresented with a huge midline sub lingual cystic swelling, inter-fering with respiration and causing progressive postural (supineposition) dyspnea. Its atypical presentation, the varied approachto its management and the rarity of the case, encouraged us topresent it.

ukul).

Inc. This is an open access article u

1. Case report

A 6-year old male child from the low socio economic status,resident of rural area presented to the department of Oral &Maxillofacial Surgery with the chief complain of swelling under thetongue for 6 months and difficult in breathing during sleep for 1month. He also had difficulty in speech and swallowing. Therewas ahistory of two previous surgeries for the same problem 3-years and6 months back, the records of which were not available. Althoughby history the procedures seemed to be carried trans-orally. Oralexamination revealed a marked midline swelling of the floor of themouth extending bilaterally, with normal overlying mucosa (Fig. 1).On examination no neck scars were evident which could suggestany trans-cervical approach or sistrunk procedure. There wasmidline sublingual scar present which could have been due toincision and drainage or incomplete enucleation of the lesion.

Examination of the neck was normal. In particular no obvioussub mental swelling could be appreciated. An Ultrasound of theneck was performed which showed a large cystic lesion locateddeep to the geniohyoid and mylohyoid muscles ({arrows}Fig. 2). Nocalcifications or mural nodules were noted in the cyst. ColorDoppler did not show any vascularity in the wall or the septum. Preand post ultrasound of the neck revealed normal thyroid gland.

Advanced imaging of the lesion like MRI or CT was not possibledue to associated postural dyspnea and lack of an intubation facilityat the center. Relevant preoperative investigations were normal.The intubation was anticipated to be difficult and appropriate

nder the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Fig. 1. Marked midline swelling of the floor of mouth extending bilaterally, withnormal overlying mucosa.

Fig. 2. High resolution ultrasonography image of the floor of mouth showing a largecystic lesion located deep to the geniohyoid and mylohyoid muscles (arrows). The cysthad a single internal septum (*) andwas inmidline reaching toward the posterior aspectof the tongue (**). It was casting bright posterior acoustic shadowing. There were lowlevel internal echoes within the cyst contents. No calcification or mural nodule werenoted in the cyst. Colour Doppler did not show any vascularity in the wall or septum.

S. Mukul et al. / J Ped Surg Case Reports 10 (2016) 3e64

provisions were made by the anesthetic team accordingly. Theinitial surgical plan was decompression of the swelling along withpossible exploration to relieve the postural dyspnea. Under generalanesthesia a midline sublingual incision was given and layer wisedissection was done to reach the lining of the cyst (Fig. 3). Theinferior extent of the lesion was found to be extending up to themylohyoid. The lining was dissected away to reach superiorly andposteriorly towards the intrinsic muscles of the tongue. The sacnarrowed towards the superior aspect in the form of a cul -de- sacto terminate over the dorsal surface of the posterior 2/3rd of thetongue. There was no identifiable tract and the sac plunged into themylohyoid muscle. The intraoperative findings and the yellowishcolor of the cystic fluid provisionally established it to be a thyro-glossal duct cyst. The cyst was removed in totality from the foramencecum to floor of the mouth. The surgical specimen (Fig. 4) was sentfor histopathological examination, which showed it to be a cysticstructure lined by pseudo-stratified to cuboidal epithelium. Atplaces squamous met aplastic changes were also evident (Fig. 5).These histopathological findings confirmed the diagnosis ofthyroglossal cyst established during the surgery. Three monthspostoperative USG finding are shown in (Fig. 6).

2. Discussion

Thyroglossal duct cyst (TGDC) is usually considered to be abenign embryonic malformation where the thyroglossal duct failsto obliterate after the descent of the thyroid gland [6]. The thyroidgland is originally located in the floor of the pharynx, between thetuberculum impar and the copula, during the 4th week of fetal life[7]. During development, the thyroid gland reaches its final position

in front of the trachea. It leaves the thyroglossal duct, a narrowcanal with an epithelial lining along the descending route of thethyroid gland. Normally, the thyroglossal duct completely disap-pears before the 10th week [7,8]. However, if the thyroglossal ductis not obliterated, the secretory epithelium of the thyroglossal ductmay result in a TGDC.

TGDC is the second most common pediatric neck mass afterlymphadenopathy [9]. Thyroglossal duct remnants occur inapproximately 7% of the population, although only a minority ofthese becomes symptomatic [9]. TGDCsmay be observed at any age,but most commonly they are noted during childhood, usually by5-years of age. TGDCs are present at birth in approximately 25% ofthe cases; one third become apparent after the age of 30 [7]. Unlikemost thyroid disorders which are found more frequently in females[7]. TGDCs are found with equal frequency in both sexes. Thyro-glossal cyst occurs in 6 different locations [10] viz. infrahyoid cysts(26e65% of TGDCs), suprahyoid cysts (20e25% of TGDC), juxtahyoidcysts (15% of TGDCs), Intralingual cysts (2% of TGDCs), Suprasternalcysts (fewer than 10%), intralaryngeal cysts (very rare) [10]. Thiscase had a location of TGDC which is also very rare.

Infection and abscess formation are frequent complications dueto a communication between the cyst and themouthwhich leads tocontamination by the oral flora. This is the most common presen-tation in adults [11]. One fourth of the patients present with adraining sinus that results from either spontaneous drainage orsurgical drainage of an abscess [12]. These lesions can also fluctuatein size, Other rare presentations can be severe respiratory distressor sudden infant death syndrome due to lesions at the base of thetongue, a lateral cystic neck mass, an anterior tongue fistula orcoexistence with branchial anomalies [12]. The two most commoncomplications of TDC are infection and malignancy. The latteroccurs in 1e4% of cases [5,13].

Fig. 5. Squamous metaplastic changes are evident.

Fig. 3. A midline sublingual incision was given and layer wise dissection was done toreach the lining of the cyst.

S. Mukul et al. / J Ped Surg Case Reports 10 (2016) 3e6 5

A sublingual cyst differs from a classical thyroglossal cyst inmany ways. First, it does not present as a neck swelling, secondlythe chief complaint is different. The common differential diagnosesof such a swelling include dermoid cyst, infected lymph node,lipoma, sebaceous cyst, branchial cyst laryngocele and cystic

Fig. 4. The surgical specimen.

hygroma [14]. Lymph nodes are often multiple and hypo echoic andshow the presence of an echogenic hilus. On aspiration there ischeesy secretion from a dermoid cyst, purulent secretion from aninfected lymph node, and air from laryngocele. The aspiratedmaterial shows fat globules and cholesterol crystals in a branchialcyst [15e17]. Lipoma has slippery edges and sebaceous cyst has adoughy feel. In cystic hygroma trans illumination is brilliantlypositive as compared to TGDC. Eric et al., stated that in a highpercentage of cases (1e2%) the thyroglossal cyst is associated withan ectopic thyroid which may be the only thyroid tissue present.Hence preoperative thyroid scan is mandatory to prevent post-operative hypothyroidism. In most cases, ultrasound supplementedby fine needle aspiration cytology is adequate for pre-treatmentassessment [18]. FNAC serves as a complementary diagnosticmethod to histopathological examination [14,19]The cytologicalfindings of a thyroglossal cyst are similar to those of a thyroid cyst.However, squamous epithelial cells are usually not seen in a thyroidcyst. This may be the only significant cytomorphologic differencebetween a thyroglossal duct cyst and a thyroid cyst [15]. A detailedhistological examination is essential not only to establish thediagnosis of TGDC but also to rule out carcinoma. No ectopic thyroid

Fig. 6. Three months post-operative USG. Post operative follow up high resolutionultrasonography image of the floor of mouth showing complete removal of the largecystic lesion. An irregular median scar is seen at the operative site (arrow).

S. Mukul et al. / J Ped Surg Case Reports 10 (2016) 3e66

was found in our patient. On ultrasonography, TGDC is highlyvariable in echogenicity. On CT scan, a TGDC cyst is seen as a wellcircumscribed, low-density lesion with a smooth, thin wall. Rimcontrast enhancement may also be observed [20]. MRI shows thetypical appearance of a simple cystic swelling which is hypo intensein T1 weighted image and hyper intense in T2 weighted images.However, CT and/or MRI scan are rarely needed in the preoperativeassessment of a suspected TGDC.

A thyroglossal cyst presenting in the neck is managed surgicallyto prevent infection, for cosmetic purpose and to prevent thedevelopment of carcinoma in 1% of cases [1]. A “Sistrunk” procedureis the recommended procedure of choice [21]. This techniqueinvolves removal of the central portion of the hyoid bone. Thisprocedure has successfully reduced the rate of recurrence comparedto local excision of the cyst [1, 7, 10]. The recurrence rate followingthis procedure is 5% [21]. Endoscopic surgery is occasionally used,particularly when the appearance of scar is concern [22]. In oursubject local excision of the cyst was done rather than the Sistrunkprocedure. Three months follow up did not show any clinical evi-dence of recurrence. This was also verified with USG (Fig. 6). It maysuggest that atypically presenting TGDC like an intralingual or asublingual TGDC does not require Sistrunk procedure. This can bethe subject for further study on a larger sample population.

References

[1] Gupta P, Maddalozzo J. Preoperative sonography in presumed thyroglossalduct cysts. Arch Otolaryngol Head Neck Surg 2001;127(2):200e2. http://dx.doi.org/10.1001/archotol.127.2.200.

[2] Ewing CA, Kornblut A, Greeley C, Manz H. Presentations of thyroglossal ductcysts in adults. Eur Arch Otorhinolaryngol 1999;256(3):136e8. Available at:http://www.ncbi.nlm.nih.gov/pubmed/10234482.

[3] Allard RH. The thyroglossal cyst. Head Neck Surg 1982;5(2):134e46. Availableat: http://www.ncbi.nlm.nih.gov/pubmed/7169333.

[4] Lindstrom DR, Conley SF, Arvedson JC, Beecher RB, Carr MH. Anterior lingualthyroglossal cyst: antenatal diagnosis, management, and long-term outcome.Int J Pediatr Otorhinolaryngol 2003;67(9):1031e4. Available at: http://www.ncbi.nlm.nih.gov/pubmed/12907063.

[5] Boswell WC, Zoller M, Williams JS, Lord SA, Check W. Thyroglossal ductcarcinoma. Am Surg 1994;60(9):650e5. Available at: http://www.ncbi.nlm.nih.gov/pubmed/8060034.

[6] Cheng C, Chang Y, Hsiao J, Wang C. Metachronous thyroglossal duct cyst andinferior parathyroid cyst: a case report 2008;24(9).

[7] Organ GM, Organ CH. Thyroid gland and surgery of the thyroglossal duct:exercise in applied embryology. World J Surg 2000;24(8):886e90. Availableat: http://www.ncbi.nlm.nih.gov/pubmed/10865031.

[8] Shahin A, Burroughs FH, Kirby JP, Ali SZ. Thyroglossal duct cyst: a cytopa-thologic study of 26 cases. Diagn Cytopathol 2005;33(6):365e9. http://dx.doi.org/10.1002/dc.20346.

[9] Enepekides DJ. Management of congenital anomalies of the neck. Facial PlastSurg Clin North Am 2001;9(1):131e45. Available at: http://www.ncbi.nlm.nih.gov/pubmed/19673381.

[10] Mittal M,Malik A, Sureka B, Thukral B. Cystic masses of neck: a pictorial review.Indian J Radiol Imaging 2012;22(4):334e43. http://dx.doi.org/10.4103/0971-3026.111488, http://www.ijri.org/article.asp?issn¼0971-3026;year¼2012;volume¼22;issue¼4;spage¼334;epage¼343;aulast¼Mittal;t¼5.

[11] Mohan PS, Chokshi RA, Moser RL, Razvi SA. Thyroglossal duct cysts: a consid-eration in adults. Am Surg 2005;71(6):508e11. Available at: http://www.ncbi.nlm.nih.gov/pubmed/16044932.

[12] Foley DS, Fallat ME. Thyroglossal duct and other congenital midline cervicalanomalies. Semin Pediatr Surg 2006;15(2):70e5. http://dx.doi.org/10.1053/j.sempedsurg.2006.02.003.

[13] Heshmati HM, Fatourechi V, van Heerden JA, Hay ID, Goellner JR. Thyro-glossal duct carcinoma: report of 12 cases. Mayo Clin Proc 2015;72(4):315e9.http://dx.doi.org/10.4065/72.4.315.

[14] Brewis C, Mahadevan M, Bailey CM, Drake DP. Investigation and treatment ofthyroglossal cysts in children. J R Soc Med 2000;93(1):18e21. Available at:http://www.ncbi.nlm.nih.gov/pubmed/10700841.

[15] Sade J, Rosen G. Thyroglossal cysts and tracts. A histological and histo-chemical study. Ann Otol Rhinol Laryngol 1968;77(1):139e45. Available at:http://www.ncbi.nlm.nih.gov/pubmed/5645136.

[16] Pounds LA. Neck masses of congenital origin. Pediatr Clin North Am 1981;28(4):841e4. Available at: http://www.ncbi.nlm.nih.gov/pubmed/7312455.

[17] Layfield LJ. Fine-needle aspiration of the head and neck. Pathology (Phila)1996;4(2):409e38. Available at: http://www.ncbi.nlm.nih.gov/pubmed/9238365.

[18] Wong KT, Lee YYP, King AD, Ahuja AT. Imaging of cystic or cyst-like neckmasses. Clin Radiol 2008;63(6):613e22. http://dx.doi.org/10.1016/j.crad.2007.12.007.

[19] Cozens NJ, Sharp JF, Carney AS. Assessment of pre-operative investigationsof thyroglossal cysts. J R Coll Surg Edinb 1996;41(6):423e4. Available at:http://www.ncbi.nlm.nih.gov/pubmed/8997042.

[20] Samara C, Bechrakis I, Kavadias S, Papadopoulos A, Maniatis V, Strigaris K.Thyroglossal duct cyst carcinoma: case report and review of the literature,with emphasis on CT findings. Neuroradiology 2001;43(8):647e9. Availableat: http://www.ncbi.nlm.nih.gov/pubmed/11548172.

[21] Brown PM, Judd ES. Thyroglossal duct cysts and sinuses: results of radical(Sistrunk) operation. Am J Surg 1961;102(4):494e501.

[22] Cai Q, Huang X, Liang F, Chen J, Liang M, Pan Y, et al. Endoscope-assistedconcurrent resection of thyroglossal duct cysts and benign thyroid nodules viaa small submental incisions. Eur Arch Otorhinolaryngol 2014;271(6):1771e5.