Riedel's Thyroiditis in a Patient with Recurrent Subacute Thyroiditis: A Case Report and Review of the Literature

Abstract

Abstract. Riedel's thyroiditis is a rare form of chronic thyroiditis, characterised by a fibroinflammatory process that partially destroys the thyroid and often involves surrounding tissues. The relationship of Riedel's thyroiditis to other forms of thyroiditis is not clear. A case of Riedel's thyroiditis in a 51-year-old woman presenting with symptoms of subacute thyroiditis, is reported. She was diagnosed with subacute thyroiditis based on clinical manifestation and laboratory results. She was treated with glucocorticoids for six weeks, and then followed-up for 12 months. Three years later, she visited with tenderness and enlargement of thyroid mass, and laboratory and radiology findings suggested that she had a malignant thyroid tumor as well as subacute thyroiditis. After thyroidectomy, histopathologic findings showed that she had Riedel's thyroiditis in the presence of subacute thyroiditis. Until now, few cases of Riedel's thyroiditis in patients with a history of subacute thyroiditis have been reported in the literature. Although the etiology of Riedel's thyroiditis is unknown, it may develop in the course of subacute thyroiditis. Case ReportA 51-year-old woman presented in our clinic with sudden onset of painful swelling in anterior neck. She had been treated for upper respiratory infection at another clinic 2 weeks prior to this visit. Her height was 156 cm, weight 61 kg, blood pressure 140/90 mmHg, pulse rate 106 per minute, respiration rate 18 per minute, and body temperature 37.1°C. Her thyroid was diffusely enlarged, quite firm, and tender. A fairly fixed nodule (2.0 × 1.0 cm) was palpated in the left thyroid gland. Abnormal laboratory findings included elevated erythrocyte sedimentation rate (ESR) of 61 mm/hr, and elevated serum T 3 of 209 ng/dL (normal, 84-157 ng/dL), elevated serum T 4 of 13.0 µg/dL (normal, 4.7-9.3 µg/dL), and a decreased TSH level of 0.1 µIU/mL (normal, 0.39-3.68 µIU/mL). Both anti-thyroperoxidase (anti-TPO) antibody and antithyroglobulin (anti-Tg) antibody were negative and anti-TSH receptor antibody was also negative. Thyroid radioiodine uptake ratio was 3.42% after 2 hours and 3.10% after 24 hours. Fine needle aspiration cytology (FNAC) of the suspect thyroid nodule was negative, however, there was infiltration of lymphocytes and leukocytes, and several giant cells were observed.

A misdiagnosed Riedel's thyroiditis successfully treated by thyroidectomy and tamoxifen

“…Cho et al thought that the subacute thyroiditis was superimposed on RT and there was no relationship between the two diseases. 13 In our case, subacute thyroiditis was diagnosed based on clinical presentation and RT was diagnosed by thyroidectomy. The histopathological examination did not show any feature of subacute thyroiditis.…”

“…9e11 There are three cases of RT reported in the literature associated with subacute thyroiditis. 12,13 Kabalak et al considered that RT may develop in the course of subacute thyroiditis because the case they reported had histopathologic features of both RT and subacute thyroiditis. 12 In the study of Papi et al, the presenting symptoms of Riedel's thyroiditis could mimic subacute thyroiditis.…”

“…12 In the study of Papi et al, the presenting symptoms of Riedel's thyroiditis could mimic subacute thyroiditis. 5 Cho et al reported a case of RT with recurrent subacute thyroiditis, 13 which presented clinical symptoms of subacute thyroiditis and pathological features of RT. Cho et al thought that the subacute thyroiditis was superimposed on RT and there was no relationship between the two diseases.…”

Atypical Presentation of Riedel’s Thyroiditis: Multifocal Nodular Fibrosis and Resolution with Levothyroxine

“…Our patient has a number of features consistent with a diagnosis of both Hashimoto’s and Riedel’s thyroiditis. Patients with Riedel’s thyroiditis are euthyroid in the early stages of their disease, although the majority become hypothyroid with progressive destruction of the thyroid parenchyma [2,14,15]. When hypothyroid, these patients usually present with either subclinical or mild hypothyroidism, and the corresponding antimicrosomal antibody titre is elevated in most cases [2,15].…”

A Case of Asymptomatic Riedel Thyroiditis with Follicular Adenoma in a Patient with a Multinodular Goiter: An Unusual Association

“…There are many reports of RT in conjuction with other thyroid diseases [6,7,8], but to our knowledge, RT with FA has not been reported yet. We describe a case of RT associated with FA occurring in a 42-year-old female patient.…”