Warthin-like variant of papillary thyroid carcinoma: single institution experience.

BACKGROUND: Correct diagnosis of the variants of papillary thyroid carcinoma (PTC) is important because these variants differ in clinical course. The Warthin-like variant (WLV) is relatively uncommon and is recognized as not different from conventional PTC. We therefore assessed the clinicopathological features of patients with WLV of PTC who were diagnosed and treated at our institution. METHODS: Of the 8179 patients treated for PTC at the Thyroid Cancer Center, Gangnam Severance Hospital, Yonsei University College of Medicine, between January 2007 and December 2012, 16 patients (0.2%) were pathologically diagnosed with WLV of PTC. Their clinicopathological features and post-operative follow-up for local recurrence and distant metastasis were retrospectively investigated. RESULT: Mean patient age was 44.9 years (range: 23-61 years), with seven (44%) being younger than 45 years. Only one of the 16 patients was male (6%). Mean tumour size was 8.9 mm (range: 3-22 mm). Extrathyroidal extension was observed in seven patients (44%), associated thyroiditis in 11 (69%) and lymph node metastasis in six (38%). The mean follow-up period was 37 months (range: 13-78 months), during which none of the 16 patients experienced recurrence or metastasis. Fifteen patients (94%) had MACIS score <6, with the remaining patient having a MACIS score of 6.33. CONCLUSION: WLV of PTC is rare, with favourable prognosis. Nevertheless, it is important to determine the histopathological features of these tumours.