Thyroid tumors with encapsulated follicular pattern : a diagnost?c dilemma

We aimed to determine the immunoreactivity for B type Raf kinase BRAF Cytokeratin CK Hector Battifora mesothelial HBME and Galectin GAL antibodies in single and combination forms to define their potential role on diagnosis in encapsulated follicular thyroid tumors creating diagnostic difficulties One hundred thirty fivethyroid tumors diagnosed with follicular adenoma FA n encapsulated minimally invasive follicular carcinoma MIFC n and encapsulated follicular variant of papillary carcinoma FVPC n were evaluated for immunohistochemically For a single antibody HBME was the most sensitive antibody for the diagnosis of FVPC vs FA whereas CK had the lowest sensitivity among the markers HBME GAL combination has the most sensitivity value for diagnosing MIFC vs FA The combination of CK HBME GAL and CK HBME BRAF have the highest sensitivity values for diagnosing FK vs FA The coexpression of the four antibodies showed average sensitivity and high specificity results as in sensitivity and in spesifity for MIFC vs FA FVPC vs FA and FVPC vs MIFC For optimum sensitivity and specificity the combination of the four markers was suggested for the diagnosis of MIFC vs FA In conclusion immunohistochemical evaluation of BRAF CK HBME and GAL in tyhroid tumors would aid the differentiation of malignant follicular lesions from benign follicular lesion Combination of different forms of antibodies in accordance with the lesion type to be distinguished may increase the sensitivity of diagnosis which needs to be confirmed with further studies