Cytokeratin 19 and Galectin-3 in thyroid neoplasms

Positivity in normal thyroid and in Hashimoto's thyroiditis has been observed⁴.

	Cytokeratin 19				Galectin-3
	negative	weak	moderate	strong	negative	weak	moderate	strong
normal thyroid	61/611				61/611
multinodular goitre	6/8 (including areas of papillary hyperplasia, which were negative)1	1/81	1/81	0/81	5/8 (including areas of papillary hyperplasia, which were negative)1, 5/53	0/81, 0/53	2/81, 0/53	1/81, 0/53
					15/35 (staining of a dominant nodule: weak staining was classified as not significant)4		20/35 (staining of a dominant nodule: 12 focal and 8 diffuse staining)4
follicular adenoma	15/20 (including areas of papillary hyperplasia, which were negative)1	1/201	2/20 (the staining was patchy)1	2/20 (although strong, the staining was extremely patchy)1	18/20 (including areas of papillary hyperplasia, which were negative)1, 5/113	1/201, 5/113	0/201, 0/113	1/201, 1/113
					9/32 (weak staining was classified as not significant)4		23/32 (10 focal and 13 diffuse staining)4
follicular carcinoma	7/121	2/121	1/121	2/121	0/121, 2/63	1/121, 1/63	6/121, 1/63	5/121, 2/63
					5/19(weak staining was classified as not significant)4		14/19 (5 focal and 9 diffuse staining)4
papillary carcinoma	0/221	0/221	2/221	24/221	4/221, 0/103	3/221, 1/103	1/221, 2/103	14/221, 7/103
					3/38(weak staining was classified as not significant)4		35/38 (7 focal and 28 diffuse staining)4
follicular variant of papillary carcinoma	0/41	0/41	0/41	4/41	1/41	0/41	0/41	3/41
anaplastic carcinoma	0/11	0/11	0/11	1/11	1/11	0/11	0/11	0/11
medullary carcinoma	0/21	0/21	1/21	1/21	1/21	0/21	0/21	1/21

Galectin-3 shows the most intense staining in the advancing tongues of minimally invasive follicular carcinoma^1,2,4 and may be helpful in differentiating a follicular adenoma from a minimally invasive carcinoma. Some consider the predictive value limited:

	Accuracy of galectin-3 in differentiating thyroid malignancy from benign lesions4
	sensitivity for malignancy	86%
	specificity for malignancy	36%
	positive predictive value	53%
	negative predictive value	75%
	diagnostic accuracy	59%

Positivity for cytokeratin 19 favours a papillary carcinoma and may be useful in the identification of the follicular variant of papillary carcinoma. Conversely, the absence of immunoreactivity for cytokeratin 19 in areas of papillary hyperplasia in any lesion may help to avoid the misdiagnosis of papillary carcinoma.

References

¹Beesley, M.F. and McLaren, K.M. Cytokeratin 19 and galectin-3 immunohistochemistry in the differential diagnosis of solitary thyroid nodules. Histopathology 2002;41:236-43.

²Bartolazzi, A., Gasbarri, A., Papotti, M., Bussolati, G., Lucante, T., Khan, A., Inohara, H., Marandino, F., Orlandi, F., Nardi, F., Vecchione, A., Tecce, R. and Larsson, O. Application of an immunodiagnostic method for improving preoperative diagnosis of nodular thyroid lesions. Lancet 2001;357:1644-50.

³Marker AJ et al. Galectin-3 immunohistochemsitry in fine needle aspirates of thyroid nodules. Pathological Society Janary 2005, abstract 48.

⁴Mehrotra, P., A. Okpokam, et al. (2004). "Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms." Histopathology 45(5): 493-500.

This page last revised 12.1.2005.

©SMUHT/PW Bishop