Ultrasound, elastography, and fluorodeoxyglucose positron emission tomography/computed tomography imaging in Riedel's thyroiditis: report of two cases

Riedel's thyroiditis: report of 7 patients and review of literature

Riedel's thyroiditis is a rare inflammatory-sclerosing thyroid disease, and its aetiology remains unknown. After a surgical biopsy to establish the diagnosis, the treatment of Riedel's thyroiditis is still challenging in most patients. The aim of this article is to report seven patients with Riedel's thyroiditis seen in a department of Endocrinology and Metabolic diseases over a period of 24 years, and based on the patient's data and the review of the literature to discuss the indications of surgery, glucocorticoids, tamoxifen and immunosuppressive drugs in the personalized treatment of patients with Riedel's thyroiditis.

IgG4-related sclerosing thyroiditis (Riedel-Struma): a review of clinicopathological features and management

We present a thorough review of the literature on Riedel thyroiditis (RT) with emphasis on aetiology, diagnosis and management, using the PubMed, Sinomed, and China National Knowledge Infrastructure databases. Although the exact aetiology of RT remains obscure, the histopathological features are consistent with a localized form of IgG4-related systemic disease (IgG4-RSD). Nevertheless, IgG4-RSD as a systemic fibroinflammatory disorder per se rarely affects the thyroid in the context of multiorgan manifestations. The initial diagnosis of RT is based on clinical history and imaging, but confirmation by histopathological examination is mandatory. In contrast to the historical surgical approach, glucocorticosteroid therapy is currently considered first line therapy, in line with the RT currently being viewed as a manifestation of, or analogous to, IgG4-RSD. For disease relapse, immunomodulatory agents (azathioprine, methotrexate, rituximab) can be used.

Reshaping the Concept of Riedel's Thyroiditis into the Larger Frame of IgG4-Related Disease (Spectrum of IgG4-Related Thyroid Disease)

Recently, Riedel's thyroiditis (RT) was assimilated into the larger spectrum of immunoglobulin IgG4-related disease (IgG4-RD) in addition to a particular frame of IgG4-related thyroid disease (IgG4-RTD), underlying IgG4-RT, IgG4-associated Hashimoto's thyroiditis (and its fibrotic variant), and IgG4-related Graves's disease. Our objective was to overview recent data on RT, particularly IgG4-RD and IgG4-RTD. The case and study- sample analysis (2019-2023) included 293 articles and selected 18 original studies: nine single case reports (N = 9, female/male = 2/1, aged: 34-79 years, 5/9 patients with serum IgG4 available data, 2/5 with high serum IgG4) and four case series (N = 21; 4/5 series provided data on IgG4 profile, 3/21 had serum IgG4 assays, and 2/3 had abnormally high values). IgG4-RD and thyroid findings were analyzed in three cohorts (N = 25). Another two studies (N = 11) specifically addressed IgG4-RTD components. On presentation, the patients may have hypothyroidism, transitory thyrotoxicosis, goiter, long-term history of positive anti-thyroid antibodies, and hypoechoic ultrasound thyroid pattern. The 5-year analysis (N = 66) showed the rate of serum IgG4 evaluation remained low; normal values do not exclude RT. Mandatory histological and immunohistochemistry reports point out a high content of IgG4-carrying plasma cells and IgG4/IgG ratio. Unless clinically evident, histological confirmation provides a prompt indication of starting corticoid therapy since this is the first-line option. Surgery, if feasible, is selective (non-responders to medical therapy, emergency tracheal intervention, and open/core needle biopsy). Current open issues are identifying the role of serum IgG4 assays in patients with IgG4-RD, finding out if all cases of RT are IgG4-mediated, applying IgG4-RTD criteria of differentiation among four entities, and providing an RT/IgG4-RTD guideline from diagnosis to therapy. It remains that the central aim of approaching RT in daily practice is the early index of suspicion in order to select patients referred for further procedures that provide enough histological/immunohistochemistry material to confirm RT and its high IgG4 burden.

Reidel's Thyroiditis, a Diagnostic and Management Challenge: A Case Report and Review of the Literature

Riedel's thyroiditis is a very rare inflammatory condition. It affects not only the thyroid gland but also the adjacent vital structures. It may also be associated with different forms of systemic fibrotic disorders. The exact etiology is unknown, but currently, the most favorable opinion is that it is a localized form of the systemic fibrotic process. We report the case of a 38-year-old woman, presented with a 10-month history of progressive hypothyroidism, dysphonia, and dysphagia. A Doppler ultrasound study revealed massive thyroid enlargement with multiple Eu TIRADS 3 and 4 nodules. Fine needle aspiration was noncontributive on two occasions. A hard subtotal thyroidectomy was performed. Pathological study confirmed Riedel's thyroiditis with the presence of IgG4 antibodies in immunohistochemistry. The patient was successfully treated with levothyroxine replacement and corticosteroid therapy with rapid resolution of obstructive symptoms. The case descriptions highlight the diagnostic challenge of this disease, describe the response to surgical management and corticosteroid therapy, and give a short review of the subject.

Riedel Thyroiditis

CONTEXT

Riedel thyroiditis (RT) is a rare inflammatory autoimmune disease that is often a clinically diagnostic dilemma because of its insidious presentation and nonspecific symptoms.

OBJECTIVE

The aim of the present systematic review and meta-analysis is to clarify the presentation, management, and outcomes of RT.

STUDY SELECTION

A systematic search of PubMed/MEDLINE and Web of Science was conducted to identify relevant reports published up to September 2019.

DATA EXTRACTION

First author, country, patient sex, ethnicity, presentation, biochemical status, duration of symptoms, histology, treatment, follow-up duration, and short- and long-term outcomes.

DATA SYNTHESIS

Data from 212 RT patients were retrieved. The mean age was 47 years with a predominantly female population (81%). Neck swelling (89%), dyspnea (50%), and neck pain (41%) were the most common presenting symptoms. Inflammatory markers were elevated in 70% to 97% and thyroid antibody positivity was present in less than 50%. Up to 82% underwent surgical intervention, with the most common being total thyroidectomy in 34% of individuals. Glucocorticoids were used in 70% of individuals with median duration 3 months. Prognosis was reasonable with 90% having resolution or improvement of symptoms.

CONCLUSIONS

This analysis is the largest and most comprehensive to date of RT and provides clinicians with vital information on the common presentation features that may alert to the diagnosis and highlight management options.

The Role of 18F-FDG PET/CT in the Management of the Autoimmune Thyroid Diseases

Objective: It is a well-known fact that positron emission tomography (PET) is an effective tool in the assessment of thyroid focal lesions, however only few studies so far have investigated its role in monitoring of autoimmune thyroid diseases (AITDs). The aim of this study is to assess if PET scan may be useful for the assessment of the thyroid gland in patients with an AITD-Hashimoto's thyroiditis. Methods: We evaluated twenty subjects with diagnosed Hashimoto's thyroiditis (proven by presence of elevated thyroid antibodies level and by thyroid imaging). The maximum standardized uptake value (SUV-max) of the thyroid parenchyma was measured using ¹⁸F-FDG-PET/CT. Control group consisted of patients who have been in carcinoma remission for other reasons than thyroid cancer and who had been investigated by PET scan to exclude carcinoma recurrence. All control group subjects had their thyroid glands intact, none of them had a medical history of thyroid disease including thyroid nodules. AITDs had been excluded in all control group subjects. STATISTICA 13.1 software was used for statistical analysis. Results: Results: The SUV-max was significantly higher in patients with an AITD than in healthy subjects (median SUV-max 3.94 vs. 1.95; p = 0.005). Conclusions: ¹⁸F-FDG-PET/CT scan may differentiate normal thyroid parenchyma from the diffused inflammatory changes of the thyroid gland in patients with AITDs. However, the researchers must be continued.

Ultrasound elastography of the thyroid: principles and current status

Ultrasound (US) elastography has been introduced as a non-invasive technique for evaluating thyroid diseases. This paper presents a detailed description of the technical principles, peculiarities, and limitations of US elastography techniques, including strain elastography and shear-wave elastography. This review was conducted from a clinical perspective, and aimed to assess the usefulness of US elastography for thyroid diseases in specific clinical scenarios. Although its main focus is on thyroid nodules, the applications of US elastography for other thyroid diseases, such as diffuse thyroid diseases and thyroiditis, are also presented. Furthermore, unresolved questions and directions for future research are also discussed.

Riedel's thyroiditis

This article describes an unusual case of Riedel's thyroiditis and discusses its imagery, pathology, and treatment.

Riedel's Thyroiditis with Intense FDG Uptake Demonstrated on FDG PET/CT

A 39 year old female presented with rapidly enlarging goitre, minimal obstructive symptoms and no constitutional symptoms. Clinical examination revealed diffusely enlarged, firm, non-tender thyroid gland. Biochemical investigations showed subclinical hypothyroidism, positive thyroid antibodies and unremarkable inflammatory markers. Ultrasound examination and CT scan of the neck were suspicious of Riedels thyroiditis. The patient was referred for a FDG PET scan to evaluate for systemic fibro-inflammatory process or lymphoma. Subsequent core biopsy of the thyroid gland demonstrated a chronic inflammatory process with fibrosis consistent with Riedels thyroiditis. A FDG PET/CT study showed diffuse FDG uptake in the thyroid gland and no abnormal retroperitoneal FDG uptake elsewhere to suggest active retroperitoneal fibrosis. The goitre reduced in size with thyroid hormone replacement and steroids, however the patient was lost to follow up.

The use of (18)F-FDG-PET/CT for diagnosis and treatment monitoring of inflammatory and infectious diseases

FDG-PET, combined with CT, is nowadays getting more and more relevant for the diagnosis of several infectious and inflammatory diseases and particularly for therapy monitoring. Thus, this paper gives special attention to the role of FDG-PET/CT in the diagnosis and therapy monitoring of infectious and inflammatory diseases. Enough evidence in the literature already exists about the usefulness of FDG-PET/CT in the diagnosis, management, and followup of patients with sarcoidosis, spondylodiscitis, and vasculitis. For other diseases, such as inflammatory bowel diseases, rheumatoid arthritis, autoimmune pancreatitis, and fungal infections, hard evidence is lacking, but studies also point out that FDG-PET/CT could be useful. It is of invaluable importance to have large prospective multicenter studies in this field to provide clear answers, not only for the status of nuclear medicine in general but also to reduce high costs of treatment.

A case of asymptomatic riedel thyroiditis with follicular adenoma in a patient with a multinodular goiter: an unusual association

BACKGROUND

Riedel's thyroiditis (RT) is a rare inflammatory disease that results in fibrosis of the thyroid gland and invasion to the surrounding structures of the neck. Follicular adenoma (FA) of the thyroid is the most common benign neoplasm of the gland.

PATIENT FINDINGS

A 42-year-old woman was referred to the outpatient clinic due to a multinodular goiter and thyroiditis. The patient was euthyroid and thyroid function tests were within normal limits. Thyroid antibodies (thyroid peroxidase antibody and thyroglobulin antibody) were high. Thyroid ultrasonography showed multiple iso-hypoechoic nodules and thyroiditis. Fine-needle aspiration cytology was performed, and it was consistent with 'suspicious for a follicular neoplasm' according to the Bethesda system. Due to the clinical findings, which included weight loss and sweating, and the cytological results indicative of a follicular neoplasm, the patient underwent a total thyroidectomy. The histopathological diagnosis was RT associated with FA. The patient was started on thyroid hormone (thyroxine) replacement therapy after surgery and was evaluated for additional fibrosis related to RT.

CONCLUSIONS

To our knowledge, this is the first case of RT associated with FA in an asymptomatic patient with a multinodular goiter and high thyroid antibodies reported in the literature.

Benign conditions of the thyroid gland

Infectious and autoimmune diseases account for the majority of benign conditions of the thyroid gland. They are usually diagnosed and followed by clinical examination and laboratory analyses, but when imaged, ultrasonography and computed tomography are the modalities of choice. In particular, fine needle aspiration under ultrasound guidance may be invaluable for diagnostic and therapeutic purposes.

The role of sonoelastography in acute, subacute and chronic thyroiditis: a novel application of the method

OBJECTIVE

Reports on sonoelastography, which provide an objective estimation of tissue elasticity, are scarce in terms of thyroiditis. The aim of this study was to prospectively assess the applicability of sonoelastography in different types of thyroiditis.

DESIGN

The study assessed and compared the thyroid tissue stiffness in patients with acute thyroiditis (AT), subacute thyroiditis (SAT), and chronic autoimmune thyroiditis (CAT) with healthy control subjects (CS), followed up for 10 weeks.

METHODS

The study group consisted of two patients with AT, 18 patients with SAT, 18 patients with CAT, and 40 CS matched for age and gender. Sonoelastography was performed at baseline, at a 4-week follow-up during treatment, and at 10 weeks following diagnosis and treatment initiation.

RESULTS

Thyroid tissue stiffness was higher in SAT at baseline (214.26 ± 32.5 kPa) in comparison with values recorded at a 4-week follow-up (45.92 ± 17.4 kPa) and at 10 weeks following diagnosis and treatment initiation (21.65 ± 5.3 kPa, P < 0.0001). Baseline thyroid stiffness in SAT was higher than that found in CAT (36.15 ± 18.7 kPa, P < 0.0001) and CS (16.18 ± 5.4 kPa, P < 0.0001). In the remission of SAT, thyroid stiffness was lower than that found in CAT (P = 0.006), while it was higher than that in CS (P = 0.0008). No difference was observed between thyroid stiffness in SAT at 4-week follow-up and in CAT. Patients with CAT presented higher thyroid stiffness than CS (P < 0.0001), which was not influenced by L-thyroxine treatment. Thyroid stiffness in patients with AT was 216.6 and 241.9 kPa at baseline; after treatment, it decreased to 17.93 and 85.348 kPa respectively.

CONCLUSIONS

Sonoelastography may assist in the diagnosis and treatment monitoring of AT, SAT and CAT, as well as in the differentiation of the various types of thyroiditis.