Thymic Hyperplasia Presenting as a Neck Mass in Graves Disease - Case Report

Abstract
We describe a female patient who presented with Graves disease and a neck mass. Radiological characteristics of the mass suggested thymic hyperplasia. She was treated with methimazole, and because the mass did not regress after six months of therapy, the patient had total thyroidectomy and thymectomy. Pathological examination was consistent with chronic lymphocytic thyroiditis and thymic hyperplasia. Microscopic changes in the thymus can be detected in one third of patients with Graves disease, but massive enlargement is rare. It has been reported that regression occurs in most patients after a euthyroid state has been achieved; however, in some patients, thymectomy may be indicated.