The accurate diagnosis of differentiated thyroid
tumors is very important for clinical management of patients. The histopathological distinction between some types of differentiated thyroid
tumors can be very difficult even for experienced pathologists. We used immunohistochemical markers from published data obtained from
DNA expression profiling, tissue microarray analysis, and immunohistochemistry to analyze a series of 157 thyroid
tumors and 5 normal thyroids. These analyses showed that several
antibodies were useful in distinguishing
follicular adenomas from follicular variant of
papillary thyroid carcinomas including HBME-1, CITED1,
galectin-3,
cytokeratin 19, and S100A4 (p < 0.0001). A combination of markers consisting of a panel of HBME-1,
galectin-3, and CK19 or a panel of HBME-1, CITED1, and
galectin-3 was usually most effective in distinguishing
follicular adenoma from follicular variant of
papillary thyroid carcinoma. Because individual
tumors may not express some of these markers, the use of a panel of
antibodies is recommended. These results indicate that some individual
antibodies or a panel of
antibodies combined with histopathological analysis can be useful in separating
follicular adenoma (FA) from follicular variant of
papillary thyroid carcinoma (FVPTC).