Endocrine Abstracts

Introduction: The association between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC) has been investigated for several years from different perspectives. In spite of that, there were only few attempts to design a common frame of references to understand the complex mutual interactions between the various pathways of inflammatory response and of thyroid tumor induction and progression. The aim of this study is to investigate the clinical characteristics and outcome of the association between chronic lymphocytic thyroiditis and papillary thyroid carcinoma.

Materials and Methods: Our study was retrospective, realized on 13 cases of simultaneous chronic lymphocytic thyroiditis and papillary thyroid carcinoma collected in ENT department of Fattouma Bourguiba Hospital of Monastir a 20-year period (2000-2020).

Results: Among the 13 patients, there were 2 men and 11 women. Mean age was 41 years [20-56]. 4 patients were under hormone replacement therapy for hypothyroidism. Patients presented to our consultation for management of anterior neck swelling in 10 cases, associated to compression symptoms in one case. We noted 2 cases of an incidental finding of thyroid nodule during an ultrasound (US) examination of neck. Thyroid nodules were highly suspicious for malignancy on US in 4 cases. The mean size of nodule was 4 cm. We noted the presence of antithyroidal antibodies in 2 cases. All of patients underwent a total thyroidectomy, associated to bilateral central neck lymph node dissection in 10 cases. Histologic examination confirmed the diagnosis of papillary carcinoma in all cases. Surgical treatment was followed by radioactive iodine therapy except in one case which was a papillary microcarcinoma measuring 4 mm. In all cases, Thyroglobulin level was undetectable after withdrawal of T4 treatment with an average follow-up of 3 years.

Conclusion: The association between chronic lymphocytic thyroiditis and papillary thyroid carcinoma is not a rare entity. Patients with CLT were younger and predominantly female. The presence of CLT in patients with PTC has been associated with better prognostic outcome, lower recurrence rate and less aggressive disease, which are the most important and well-known prognostic variables for thyroid cancer mortality.