Endocrine Abstracts

JOINT2587

Introduction: Papillary thyroid cancer of the Warthin type (WLPTC) is a rare subtype of papillary thyroid cancer named for its similarity to Warthin’s tumor of the salivary glands. Histopathologically, it is characterized by the formation of papillary like structures, the presence of oxyphil cells, and lymphocytic infiltration. WLPTC has been shown to occur more frequently in women, especially in the 4th decade of life, and is often associated with autoimmune thyroid disease.

Aim of the Study: A retrospective review of data from 30 patients with WLPTC diagnosed from 2021 to 2025 was performed. The aim of the analysis was to characterize the patients, including demographic data, histopathological findings, and treatment course. In the group of 30 patients, the majority were women (n = 26, 86%) and the remainder were men (n = 4, 14%). The mean age of the patients was 46 ± 11 years, with a median of 49 years. According to the TNM classification, the distribution was as follows: pT1a in 13 patients (43%), pT1b in 12 patients (40%), and pT2 in 5 patients (16%); no nodules were larger than 4 cm. Multifocality was observed in 24 cases (80%), and coexisting subtypes—classic, follicular, oncocytic, and hobnail—were identified. Lymph node metastases were confirmed in the central compartment (pN1a in 5 of 29 cases, 17%) and in the lateral compartment (pN1b in 1 of 29 cases, 3%). No distant metastases were found. In 18 cases (60%), the nodule was found to be intrathyroidal; in 5 cases (17%), there was extension into the capsule; and in 7 cases (24%), microscopic extrathyroidal extension was observed. Angioinvasion was present in 5 cases (17%). Coexisting autoimmune thyroiditis was found in 26 cases (86%). According to the AJCC 8th edition classification, 100% of the patients were classified as Stage I. Based on the ATA 2015 risk stratification: 9 out of 29 patients (31%) were assessed as low risk, and 20 out of 29 patients (69%) as intermediate risk. In our group, 29 out of 30 patients (96%) received radioactive iodine (RAI) treatment; the response to treatment was excellent in 26 cases (90%), with 1 case showing a biochemically incomplete response, while 3 patients are awaiting results.

Conclusions: The Warthin subtype, although very characteristic, is rarely diagnosed. It is associated with autoimmune thyroiditis, exhibits a clinical course like other papillary carcinoma subtypes, and has a good prognosis that also depends on the coexisting subtype.