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| Year : 1984 | Volume
: 30
| Issue : 3 | Page : 175-8 |
Thyroglossal cyst (a clinicopathological evaluation with special reference to its malignant potential).
Ranadive NU, Shroff CP
How to cite this article:
Ranadive N U, Shroff C P. Thyroglossal cyst (a clinicopathological evaluation with special reference to its malignant potential). J Postgrad Med 1984;30:175 |
How to cite this URL:
Ranadive N U, Shroff C P. Thyroglossal cyst (a clinicopathological evaluation with special reference to its malignant potential). J Postgrad Med [serial online] 1984 [cited 2023 Mar 31];30:175. Available from: https://www.jpgmonline.com/text.asp?1984/30/3/175/5455 |
Thyroglossal cyst is a common congenital anomaly of the thyroid gland. The clinical diagnosis of the lesion is usually accurate due to its anatomical location. Complications like infection or sinus formation are common. But malignant transformation is rather rare. First case was reported in 1915 and through 1981, 100 cases are added.[1],[5] One case of papillary carcinoma in our series was compared with remaining benigh thyroglossal cysts.
The records of surgical pathology were studied from the period 1978 to 1982. Two hundred ninetynine thyroid specimens and 16 thyroglossal cysts were received during the period. Histologically, nineteen were malignant lesions but of these, nine were follicular carcinomas, nine were papillary carcinomas, and only one was a medullary carcinoma. Thyroglossal cyst specimens were processed entirely for histological study. Clinical data in these cases did not reveal any abnormality in thyroid functions.
The clinical data, anatomical site, gross appearance of cysts and histology are shown in [Table - 1] The presenting symptom was painless swelling in the middle of the neck which was gradually increasing in size over a period of six months to two years. In the case of malignancy, sudden increase in size was observed over two months.
Gross appearance
The size of the cysts varied between 1.5 and 5 cm in diameter. On cutting open, the cysts were found to contain either serous or haemorrhagic fluid in majority of the cases and colloid material in one. The walls were smooth. In the case of malignancy in median ectopic thyroid, the cyst was 5 x 1.5 x 4.5 cm in size, and was multi loculated. Tiny projections were seen in some loculi. A few gritty areas were felt in the thickened fibrosed wall.
Histopathologic features
In the case of malignancy, the cyst lining revealed columnar epithelium in some areas; in other areas, the lumen was filled with papillary processes covered with cuboidal to columnar epithelium in double or multilayers [Fig. 1]. The cells were irregularly arranged with loss of polarity. The nuclei were ground glass type [Fig. 2]. The epithelium rested on a thin or broad fibro vascular connective tissue cone. Bluish purple laminated calcific structures, the psammoma bodies, were seen at the base of papillae, outside the mucosa of the cyst and in the walls of blood vessels. The tumour was infiltrating into the cyst beyond the mucosa [Fig. 3]. The cyst wall revealed islands of normal thyroid acini filled with colloid, separated by fibrous connective tissue, lymphocytic infiltrate and tumour tissue. All these components were seen in multiple sections.
This patient with papillary carcinoma had her thyroid gland in its normal anatomic situation. Thyroid imaging in the case with papillary carcinoma and thyroglossal cyst was not done. Follow-up examination during the last five months did not show any abnormality in the thyroid gland and at the operation site.
Histologic features in the remaining fifteen cases showed squamous epithelial lining in five cases, columnar lining in eight cases and ulceration and granulation tissue in two cases. [Table - 1].
The male to female ratio in 16 cases of thyroglossal cyst was 1:.22. The female preponderence in thyroglossal cyst as well as in papillary carcinoma cases was also reported by others.[2],[3],[4],[8] The age incidence of the cysts in the present series varied between 7 and 54 years. This was because the lesion is usually asymptomatic.
Papillary carcinoma was seen in a 30 year old female patient [Table - 1]. In India, the first, second and the third decades were shown to be the commonest age groups in cases of papillary carcinoma of the thyroid gland.[2] Sudden increase in size was the only warning symptom in case of malignant transformation, in our series. Yet we know that papillary carcinomas present as occult cancers.
Histology in the majority of thyroglossal cysts showed columnar epithelium [Table - 1]. Squamous lining was seen in the cases of fistulae which could be due to metaplastic change as a result of infection. The ectopic thyroid tissue was found only in the case of papillary carcinoma. Judd's study on 381 cases of thyroglossal cysts did not reveal either ectopic thyroid gland or a malignant change.[4] Yet, in another series of 371 cases of thyroglossal cysts, ectopic thyroid tissue was present in 45% and in 1.8% of these, there was a malignant transformation.[5] Presence of an ectopic thyroid in a thyroglossal cyst wall must be studied carefully and multiple sections be taken to rule out any malignant change.
Eightyfive per cent of cancers in relation to thyroglossal cysts were papillary carcinomas. Papillary carcinoma is one of the common type of malignancies affecting the anatomical normal thyroid gland. This is one of the reasons why papillary carcinomas are more commonly seen in ectopic thyroid tissue. Yet, as to why follicular carcinoma which is another common histological type is much rarer in the thyroglossal duct carcinomas is difficult to explain. Hypothetically, one may be tempted to state that a cyst favours a papillary growth as seen in other cystic tumours like ovarian tumours. Literature review indicates that prognosis of papillary carcinoma arising in the median ectopic thyroid appears to be very good.[5]
Presence of ectopic thyroid in a thyroglossal duct, a symptomless normal thyroid gland indicates that the papillary carcinoma originated from the ectopic gland in the wall of the cyst. Nuttal[7] had put forward three objections to this theory. His first objection was lack of adequate microscopic documentation of normal thyroid or thyroglossal duct remnants in the neck which is not so in the present case. His second objection was that all documented cases were papillary. But currently, other histological types including follicular, squamous, basal cell, and anaplastic carcinomas were reported.[1],[3],[6] His third objection was that the pathological examination of the main gland was sketchy or lacking. A short follow-up in our case is not substantial or conclusive. We suggest a long term follow-up to exclude the possibility of a probable metastasis from the anatomically normal thyroid gland in such cases.
We are grateful to the Dean, Lokmanya Tilak Municipal Medical College and Lokmanya Tilak Municipal General Hospital, for allowing us to publish this paper.
| 1. | Akbari, Y., Richter, P. M. and Papadakis, L. E.: Thyroid carcinoma arising in thyroglossal duct remnants. Arch. Surg., 94: 235-239, 1967.  |
| 2. | Diwan, R. V.: Thyroid carcinoma-A clinico-radiological study and review of literature. J. Assoc. Phys. India, 28: 837845, 1978. |
| 3. | Joseph, T. J. and Komorowski, R. A.: Thyroglossal duct carcinoma. Hum. Pathol., 6: 717-729, 1975. |
| 4. | Judd, E. S.: Thyroglossal duct cysts and sinuses. Surg. Clin. North Amer., 43: 1023-1032, 1963. |
| 5. | LiVolsi, V. A., Perzin, K. H. and Savetsky, L.: Carcinoma arising in median ectopic thyroid (including thyroglossal duct tissue). Cancer, 34: 1303-1315, 1974. |
| 6. | Nussbaum, M., Buchwald, R. P., Ribner, A., Mori, K. and Litwins, J.: Anaplastic carcinoma arising from median ectopic thyroid (thyroglossal duct remnant) Cancer, 48: 2724-2728, 1981. |
| 7. | Nuttal, F. Q.: Cystic metastases from papillary adenocarcinoma of the thyroid with comments concerning carcinoma associated with thyroglossal remnants. Amer. J. Surg., 109: 500-505, 1965. |
| 8. | Page, C. P., Kenmerer, W. J., Haff, R. C. and Mazzaferri, E. L.: Thyroid Carcinomas arising in thyroglossal ducts. Alan. Surg., 180: 799-803, 1974. |
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