The tall cell variant (TCV) of papillary carcinoma has been associated with an aggressive biological behavior. Histologically, these tumors are characterized by the presence of tall oxyphilic cells with the height twice the size of the width. The immunohistochemical profile of these neoplasms, however, has not been reported. We intend to study 18 cases of TCV and to evaluate several tumor markers by the immunohistochemistry technique to investigate if the antigenic profile of TCV differs from usual papillary cancer and if it causes any prognostic significance.
