Abstract
An Immunohistochemical examination was conducted using commercially available primary antibodies to evaluate their utility for differential diagnosis of equine thyroid tumors i.e. non-functional C-cell adenoma, medullary carcinoma and follicular adenocarcinoma. The primary antibodies used in the study were antibodies against calcitonin, calcitonin-gene-related peptide (CGRP), thyroglobulin, chromogranin A, neuron specific enolase (NSE), synaptophysin and somatostatin. Calcitonin, NSE and synaptophysin were found to be useful to identify the origin of tumors as C-cells and thyroglobulin as follicular epithelial cells. In addition, it was found that detection of CGRP and chromogranin A is related with the functional status of C-cells. The carcino-related-gene (CRG) product, bcl-2, was positive in medullary carcinoma and follicular adenocarcinoma, and weakly positive to negative in non-functional C-cell adenoma. Another CRG product, p53, was positive in non-functional C-cell adenoma and follicular adenocarcinoma, and negative in medullary carcinoma. These results suggest that the expression pattern of 9 antigens used may be of help for the differential diagnosis of these tumors.
