The Warthin-like variant of papillary thyroid carcinomas: a clinicopathologic analysis report of two cases.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma, comparising various subtypes including classical PTC (accounting for approximately 55–65 % of cases) and several variants. The identified variants include papillary microcarcinoma, encapsulated variant, follicular variant, diffuse sclerosing variant, tall cell variant, columnar cell variant, cribriform-morular variant, and Warthin-like variant (WLV-PTC). WLV-PTC is a rare malignant neoplasm. The present study introduced two cases of WLV-PTC from Affiliated Hospital of Chengde Medical College in retrospect. The macroscopic characteristics, histological feature, immunophenotyping, gene mutations, local invasion, and distant metastasis of the tumors were observed, and the relevant literature on WLV-PTC was reviewed. The tumor cells exhibited nuclear the characteristics similar to those of classic papillary thyroid carcinoma. Immunohistochemical analysis showed strong positivity for thyroid transcription factor 1, cytokeratin 19, Galectin-3, and CK, weak positivity for thyroglobulin, and the Ki-67 proliferation index ranging from 5 to 10 %. Gene mutation analysis revealed that Case 1 had a BRAF V600E mutation, whereas Case 2 had a wild-type mutation. WLV-PTC has histological features similar to those of Warthin tumor originating from salivary gland. The prognosis of WLV-PTC is similar to that of conventional PTC of comparable size and stage. [ABSTRACT FROM AUTHOR]