Warthin-like papillary thyroid carcinoma accompanying classical papillary carcinoma: Report of three cases and systematic review of the literature

Background: We present three cases of Warthin-like papillary thyroid carcinoma (WLPTC) and perform a systematic review of the literature to evaluate the relationship between WLPTC and clinicopathological features. Methods: Relevant articles were obtained by searching the PubMed and KoreaMed databases using the following Medical Subject Headings (MeSH) terms and keywords: "Warthin papillary thyroid carcinoma". The following data were extracted from the eligible studies: age, gender, tumor size, lymphocytic thyroiditis, lymph node metastasis, extrathyroidal extension, multifocality, and BRAF mutation. Results: A total of 48 publications were identified, and 32 studies including the current study were ultimately included. A total of 164 patients were included in analysis. We found 31% of patients (51/164) had lymph node metastasis. Only four case reports described the histologic type of the metastasized lymph nodes. We found that lymph node metastases were primarily from classical PTC. Only one case of seven metastatic lymph nodes metastasized from WLPTC. We noted that five WLPTC tumors were accompanied by classical PTC on background. Conclusions: WLPTC does not metastasize to lymph node frequently and further studies of the mechanism of metastatic lymph nodes presenting a Warthin tumor-like pattern are needed.