Papillary thyroid tumors: Diagnostic value of CD56 and Cytokeratin 19.

Introduction: Noninvasive Follicular Thyroid Neoplasm With Papillary-like Nuclear Features (NIFTP) is a tumor composed exclusively of follicles lined by cells having nuclear characteristics of papillary carcinoma. Morphological diagnosis is often difficult especially in the cases in which these nuclear abnormalities are focal.

Aim: To investigate the contribution of the immunohistochemical study with anti CD56 and anti cytokeratin 19 in the positive diagnosis of NIFTP.