Thyroid Science 6(10):CR1-3, 2011	www.ThyroidScience.com
Case Reports

Papillary Carcinoma in a Thyroglossal Duct Cyst:

A Case Report, Review of Literature, and

Diagnostic Pitfalls in Fine Needle Aspiration Cytology

Narayani Joshi,	MD1	and B.P. Nag	,	MD2

1Mahatma Gandhi Medical College & Hospital Jaipur, Department of Pathology

2Mahatma Gandhi Medical College & Hospital Jaipur

*Corresponding Author: Dr. B.P.Nag

D-174, Vineet Marg, Bapu Nagar, Jaipur (Rajasthan) 302015

Phone no.: 09828087246	E-mail: drbpnag@gmail.com

Received: August 7, 2011

Accepted: September 28, 2011

Abstract. The incidence of papillary carcinoma arising in a thyroglossal duct cyst is rare and occurs less than 1% of thyroglossal cysts. We report a case of cystic swelling in the mid-line neck in a young female patient. Fine needle aspiration of the cyst revealed colloid material and macrophages CT scan showed a cystic lesion with calcification. Histopathological examination of the cyst showed papillary carcinoma of the thyroid gland.

Keywords • Papillary carcinoma • Thyroglossal duct cyst • Psammoma bodies

Introduction

Thyroglossal duct cysts are the most common non-odontogenic (tooth-forming) cysts in the neck.[1] The cysts are a congenital anomaly that arises from remnants of the thyroglossal duct. It is estimated that 7% of the adult population have these remnants.[2]

The cysts are usually asymptomatic and presen
tation of the patient with carcinoma is indistin
guishable from the benign common thyroglossal duct cyst.[3] Papillary carcinoma occurs in less than 1% of patients. In majority of patients, histological features of papillary carcinoma of the thyroid tissue are de
monstrated.[4] Approximately 150 cases of papillary carcinoma arising in thyroglossal duct cysts have been documented in the English language literature.[5]

Case Report

A 20-year-old female patient who was asympt
omatic presented to the Department of ENT, Mahatma Gandhi Medical College and Hospital. The patient had midline neck swelling for 1.5 years. On exam
ination, the swelling was 2 x 2 x 1.5 cm in size, cystic, and moved with deglutination and on protrusion of her tongue. She had no history of pain, and she had no as
sociated cervical lymphadenopathy.

Fine needle aspiration cytology was done. The smear revealed colloid material and a few macro
phages (Figure 1). Indirect laryngoscope was done and both vocal cords were found to be normal.

Figure 1. Cytosmear showing

macrophages and colloid in

the background.

Thyroid function laboratory tests and other bio
chemical and hematological parameters were within their reference ranges. Ultrasonography showed a septate cyst of 3 x 3 cm in size in the submandibular region. The cyst extended up to the upper pole of the right lobe of the thyroid gland and reached to midline. Both lobes of the thyroid gland were nor
mal in size and echotexture. CT scan revealed cystic swelling of 3 x 3 cm in size on the right side and

Figure 2. CT scan showing cystic

lesion with irregular calcification.

anterior to the right lobe of the thyroid gland with foci of calcification (Figure 2).

The patient underwent excision of the cyst by Sistrunk operation.[6] The cyst was adherent to the hyoid bone. The resected specimen was sent to the department of pathology. On gross examination, the cyst measured 2 x 2 x 1.5 cm in size and was attached

Figure 3. Malignant cells arranged in

papillary structure with central fibro-

vascular core. HE 4 x 10 = 40.

to a piece of hyoid bone. On cutting, a roughened in
ternal surface of the cyst wall was seen. Microscopic examination revealed malignant cells arranged in a papillary structure with a central fibrovascular core with multiple calcifications (Psammoma bodies) (Figure 3). The malignant cells displayed optically clear nuclei and some of the cells contained intra
nuclear inclusions (Figure 4).

Discussion

Carcinoma of the thyroglossal duct cyst is rare. The clinical presentation is identical to that of a benign cyst.[1] The first case was reported by Ucher
mann in 1915.[7] The cysts occur most commonly in young women. Geok et al reported a case of papil
lary carcinoma of the thyroglossal duct cyst in a 15 yrs old girl.[8] Yang also reported papillary carcino
ma in thyroglossal cysts in younger women with a sex ratio of 1.5:1.[9] In the present case, FNAC was

Figure. 4. Malignant cells display optically

clear nuclei, some of the central.

done. Cytosmear showed only macrophages and colloid material. The false negative result on fine needle aspiration cytology (FNAC) was due to cystic fluid that was aspirated leading to hypocellularity. Godara et al reported on fine needle aspiration the features of colloid goiter with no evidence of malig
nancy in thyroglossal duct cyst carcinoma.[10] Only fifteen cases of papillary carcinoma in thyroglossal duct cysts diagnosed by FNAC has been reported. Agarwal et al.[11] discussed the diagnostic pitfall of FNAC of papillary carcinoma arising in thyroglossal duct cyst.

Ultrasonography of the cyst revealed a cystic mass with normal thyroid tissue. Smiti reported ultrasono
graphy of the neck showing a well-defined cystic mass in the left paramedian region at the level of hyoid bone with calcification and a normal thyroid gland.[12] CT scan done in our case showed a cyst of 3 x 3 cm in size septate with multiple foci of calcification similar to the findings reported by Taori et al. They reported a midline multi cystic lesion with foci of irregular cal
cification, a normal thyroid gland, and absence of involvement of neck lymph nodes.[13]

The most common histological pattern demon
strated in patients is that of papillary carcinoma of the thyroid gland, similar to the histological findings described in our case. A case of papillary carcinoma in the thyroglossal cyst without carcinoma in the thyroid gland has also been reported by Yavu et al.[14]

Papillary carcinoma in the thyroglossal duct cyst has a good prognosis and metastasis is reported to be exceedingly rare.[9]

Conclusion

We conclude that papillary carcinoma should be suspected when there are imagine features such as calcification in a midline cystic mass with a normal thyroid gland. This case is reported in view of its rarity and highlights the diagnostic pitfalls of fine needle aspiration cytology.

References

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2.	Ellis, P. and Van Nostrand, A.W.: The applied anat
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3.	Billy, R., Walton, D.O., and Koch, K.E.: Presentation and management of thyroglossal duct cyst with a papillary carcinoma. South Med. J., 90(7):758-761, 1997.

4.	Reede, D.L., Bergeron, R.T., and Som, P.M.: CT of thyroglossal duct cysts. Radiology, 1985; 157:121-
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5.	Chen, F., Sheridan, B., and Nankervis, J.: Carcinoma of thyroglossal duct: case report and a literature re
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6.	Sistrunk, W.E.: The surgical treatment of cyst of the thyroglossal tract. Ann. Surg., 71:121-124, 1920.

7.	Kristensen, S., Juul, A., and Moesner, J.: Thyroglos

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8.	Geok, C.T., Mohd Sidik Shiran, M.S., Swarminathan, M., et al.: Papillary carcinoma of thyroglossal duct cyst in a 15 years old girl. Int. J. Paediatr. Otorhin
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9.	Yang, Y.J., Haghir, S., Wanamaker, J.R., et al.: Diag
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10.	Godara, R., Marwah, S., Ahuja, V., et al.: Papillary carcinoma in thyroglossal duct cyst: A case report and literature review. J. Chin. Clin. Med., 4 (4): 238-240, 2009.

11.	Agrawal, K., Puri, V., and Singh, S.: Critical ap
praisal of FNAC in the diagnosis of primary papillary carcinoma arising in thyroglossal cyst: A case report with review of the literature on FNAC and its diagnostic pitfalls. J. Cytol., 27(1): 22-25, 2010.

12.	Smiti, S. and Mahmood, N.S.: Papillary carcinoma arising from a thyroglossal duct cyst. Ind. J. Radiol. Imag., 19 (2): 120-122, 2009.

13.	Taori, K., Rohatgi, S., Mahore, D.M., et al.: Papillary carcinoma in a thyrogalossal duct cyst: a case report and review of literature. Ind. J. Radiol. Imag., 15 (4):531-533, 2005.

14.	Albayrak, Y., Albayrak, F., Kuf Kaya, Z.U.,et al.: A case of papillary carcinoma in a thyroglossal cyst without a carcinoma in the thyroid gland. Diagn. Cytopathol., 39: (1) 38-41, 2011.