Fine needle aspiration of a warthin-like thyroid tumor -: Report of a case with differential diagnostic criteria vs. other lymphocyte-rich thyroid lesions

BACKGROUND: Warthin-like papillary carcinoma of the thyroid (WLT), a recently described entity, should be included among lymphocyte-rich lesions of the thyroid. The diffuse sclerosing variant of papillary carcinoma (DSV), the oxyphilic variant of Hashimoto thyroiditis (OHT) and primary lymphoplasmacytic lymphoma (PLT), the FNA appearances of which have many similarities, belong to the same category. CASE REPORT: A case of WLT occurred in a 31-year-old female, who was admitted with a 1.5-cm, nodular lesion of the thyroid; fine needle aspiration (FNA) yielded a diagnosis of papillary carcinoma. Histologic examination revealed the characteristic picture of WLT, with papillae lined with large, oxyphilic thyreocytes, with nuclear pseudoinclusions and grooves filled with lymphocytes, mostly mature plasma cells. The FNA picture of WLT was compared with those of the other lymphocytic-rich lesions of the thyroid-DSV, OHT and PLT. CONCLUSION: The differences between these forms provide diagnostic criteria that could be useful for the preoperative management of patients affected by suspicious, inflammationlike thyroid lesions.