Immunohistochemical study proves valuable in the diagnosis of neoplastic pathology. Its application allows us to differentiate the origin of tumors, as seen with thyroglobulin and TTF1 in well-differentiated tumors of follicular origin and calcitonin or other neuroendocrine markers for tumors arising from C cells. At times, immunohistochemical study becomes necessary for the classification of thyroid carcinomas arising from follicular cells, although specific antibodies that would enable the exclusion of malignancy or differentiation between follicular carcinomas and papillary carcinomas have generally not been found; hence, various antibody panels are utilized. HMBE1 and galectin 3 can be beneficial in distinguishing malignancy from benignity, while CK19, galectin 3, and HMBE1 aid in identifying papillary carcinomas of follicular variant. In the differential diagnosis depending on histological morphology, various panels with automated protocols prove greatly useful.