Risk of malignancy from thyroid nodular disease as an element of clinical management of patients with Hashimoto's thyroiditis

Abstract

Background: Many studies have investigated the association between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC), but clinical management of this condition has never been addressed specifically, even in recent guidelines. Surprisingly the likelihood of a nodule as being cancerous in a CLT has never been explicitly expressed in terms of relative risk.

Methods: This study was based on a retrospective analysis of 404 patients undergoing total thyroidectomy.

Results: Sixty-nine patients (17.1%) had histological findings of true CLT, and 36.2% had concurrent PTC versus 22.6% of patients in the non-CLT group (p < 0.05), with a tumour risk in the CLT group of ×1.6 (95% CI = 1.21-1.94, likelihood ratio = +1.63).

Conclusions: Patients with CLT and a nodular condition have a ×1.6 increased risk of harbouring a PTC. Moreover, these patients develop multicentric PTC more frequently, and, as a result, total thyroidectomy should always be considered.