Thyroid transcription factor 1 (TTF-1) and p63 expression in two primary thyroid papillary carcinomas of branchial cleft cysts

Abstract

Malignant lateral cervical cysts can be related to metastatic tumors or rarely to primary thyroid carcinoma arising in branchial cleft cysts. This study evaluates the expression of thyroid-associated transcription factor-1 (TTF-1) and p63 in three branchial cleft cysts and in two primary thyroid papillary carcinoma of branchial cleft cysts. TTF-1 was negative in the nuclei of the lining epithelia of branchial cleft cysts, but positive in the adjacent normal thyroid tissue, while TTF-1 was positive in the nuclei of the lining epithelia and in the nuclei of the papillae and follicles in branchial cleft cysts with ectopic thyroid carcinoma. P63 was positive in the nuclei of the lining epithelia of branchial cleft cysts, but negative in the adjacent normal thyroid tissue. Papillary thyroid carcinoma of branchial cleft cysts displayed p63-positive foci. In conclusion, our results demonstrate that TTF-1 cannot distinguish between primary and metastatic tumors of branchial cleft cysts. The detection of p63 in papillary thyroid carcinomas of branchial cleft cysts could suggest that p63 contributes to the onset of this tumor. It is really important to evaluate if the case has a metastatic derivation or represents papillary thyroid carcinoma arising in ectopic thyroid tissue in a branchial cleft cyst.

Expression of Cytokeratin 19 and Protein p63 in Fine Needle Aspiration Biopsy of Papillary Thyroid Carcinoma

“…35 It is strongly expressed in the basal and parabasal layers, the stem cell reservoir of squamous epithelia and tumors of squamous origin. 36,37 p63 Has been recently found in many different benign lesions of the thyroid, such as Hashimoto's thyroiditis, 18,38 massive squamous metaplasia 39 and solid cell nests 19 and in malignant tumors, such as sclerosing mucoepidermoid carcinoma with eosinophilia, 40 thyroid carcinoma showing thymuslike differentiation 41 and primary thyroid papillary carcinomas of branchial cleft cysts 42 and in papillary carcinoma 20,22,43 and anaplastic carcinoma. 24,44 In our cases, p63 positivity was observed in 74% of cytologic smears and in 93% of PTC histologic specimens, while only 1 benign case (4.5%) showed a few p63-positive cells in FNAB smears, but coexpression of CK19 was not present.…”

Thyroid papillary carcinoma arising in ectopic thyroid tissue within a branchial cleft cyst

“…In order to characterise a thyroid carcinoma in ectopic positions as primary, some criteria must be taken into account, such as the absence of an individual history of malignancy, a normal or absent orthotopic thyroid gland and separate blood supply from extracervical vessels 7. Immunohistochemical positive staining of Tg and TTF-1, as in our case, could help in the identification of a PTC located in the branchial cyst, although it cannot distinguish between primary and metastatic tumours 18. The differential diagnosis should also be made from a cystic lymph node metastasis of occult orthotopic PTC and is often difficult 19…”

Clinicopathological significance of DNA fragmentation factor 45 and thyroid transcription factor 1 expression in benign and malignant lesions of the gallbladder

“…Recent findings show that TTF-1 expression level is significantly correlated with growth, development, malignant behavior and prognosis of thyroid carcinoma and non-small-cell lung cancer (NSCLC). Tumors with high TTF-1 expression are well differentiated, progress slowly with almost no lymph node metastasis, and usually have a good prognosis [16,18,24]. In addition, many studies show that TTF-1 expression is significantly correlated with growth, development, malignant be- havior and prognosis of other tumors, such as cervical small cell neuroendocrine carcinomas, ovarian cancer and some rare intracranial tumors [14,19,20].…”

“…The expression level of TTF-1 is significantly correlated with growth, development, malignant behavior and prognosis of thyroid and lung cancer [16][17][18]. In addition, recent studies have suggested that TTF-1 is significantly correlated with growth, development and malignant behavior of cervical small cell neuroendocrine carcinomas, ovarian cancer and some rare intracranial tumors [14,19,20].…”