Positron emission tomography as an aid in the diagnosis and follow-up of Riedel's thyroiditis

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.

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.

Rituximab: a novel treatment for refractory Riedel's thyroiditis

This case report reviews the rare condition of Riedel's thyroiditis via a patient case. The report highlights the difficulties that one may encounter when managing such a case in regards to patient symptoms, side effects of medications and the relapsing nature of the condition. The case report also highlights novel treatment in the treatment of Riedel's thyroiditis, rituximab, how this works and the resolution of symptoms that we have achieved with our patient on this treatment.

Learning points

Riedel's thyroiditis is characterised by chronic inflammation, which causes dense fibrosis in the thyroid gland.Riedel's thyroiditis can present with neck pain, dysphagia and dyspnoea with a firm, non-tender mass found on examination.Riedel's thyroiditis is part of the IgG4-related systemic disorders.Rituximab is a monoclonal antibody that works against the protein CD20.

Assessment of Therapy Response by FDG PET in Infection and Inflammation

Positron emission tomography (PET) is a well-known imaging modality in assessing the treatment response to chemotherapy or radiotherapy in various malignancies. A systematic review of the literature reveals a few publications reporting evaluation of the treatment response in benign conditions using PET/computed tomography. PET holds a promising future role in the follow-up of inflammatory or infectious diseases. In this article, [(18)F]Fluorodeoxyglucose PET as a tool in the evaluation, treatment, and follow-up of infectious and inflammatory diseases is discussed.

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.

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

BACKGROUND

Riedel's thyroiditis (RT) is a rare disease characterized by a chronic inflammatory lesion of the thyroid gland with invasion by a dense fibrosis. Publications of the imaging features of RT are scarce. To our knowledge, ultrasound elastography (USE) findings have not been previously reported. Therefore, we describe two patients with RT who were imaged with ultrasonography (US), USE, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

SUMMARY

Two women were referred for a large, hard goiter with compressive symptoms (dyspnea and dysphagia); in one patient, the goiter was associated with retroperitoneal fibrosis. In both cases, RT was confirmed by surgical biopsy with pathological examination. Thyroid US imaging was performed with a US scan and a 10-13 MHz linear transducer. The hardness of the tissues was analyzed using transient USE (ShearWave, Aixplorer-SuperSonic Imagine). PET/CT scanning was performed with a Philips Gemini GXL camera (GE Medical Systems). In the first patient, US examination revealed a compressive multinodular goiter with large solid hypoechoic and poorly vascularized areas adjacent to the nodules. The predominant right nodule was hypoechoic with irregular margins. The second patient had a hypoechoic goiter with large bilateral hypoechoic areas. In both cases, an unusual feature was observed: the presence of tissue surrounding the primitive carotid artery, associated with thrombi of the internal jugular vein. Further, USE showed heterogeneity in the stiffness values of the thyroid parenchyma varying between 21 kPa and 281 kPa. FDG-PET/CT imaging showed uptake foci in the thyroid gland. In both cases, US showed a decrease in the thyroid gland volume and the disappearance of encasement of the neck vasculature in response to corticosteroid treatment. In contrast, the FDG-PET/CT features remained unchanged.

CONCLUSIONS

US features, such as vascular encasement and improvement under corticosteroid treatment, seem to be specific to this rare disease. For the first time, USE documents the hardness of RT tissues. Apart from the FDG-PET/CT findings that merit further investigation, US and USE prove useful tools in the assessment of such a rare disease.

Invasive fibrous thyroiditis (Riedel thyroiditis): the Mayo Clinic experience, 1976-2008

BACKGROUND

Invasive fibrous thyroiditis (IFT) is the rarest form of thyroiditis, and reports are often limited to case reports and small case series. In this study, we aimed to summarize our institutional experience with IFT since 1976.

METHODS

We retrospectively reviewed the cases of all patients with IFT evaluated at Mayo Clinic, Rochester, Minnesota, from 1976 through 2008, with special emphasis on clinical presentation, associated risk factors, associated comorbid conditions, complications, and treatment.

RESULTS

Twenty-one patients met our inclusion criteria of (i) IFT confirmed by pathologic review at our institution and (ii) evidence of extension of fibrosis outside the thyroid capsule. Most patients (17, 81%) were women (mean age, 42 years). Presenting symptoms included pain (24%), dysphagia (33%), vocal cord paralysis (29%), and tracheal narrowing (48%). Three patients had associated hypoparathyroidism. Sixteen (76%) had a history of tobacco use, and 10 (48%) were current smokers. Fibrosing mediastinitis was present in four, orbital fibrosis in one, retroperitoneal fibrosis in three, and pancreatic fibrosis in one (38% had extracervical fibrotic processes). Eighteen patients had partial thyroidectomy, 7 (39%) of whom had surgical complications involving vocal cords and parathyroid. Two required tracheostomy. Thirteen had corticosteroid therapy; six received tamoxifen. There was no cause-specific mortality, and the fibrotic process stabilized or partially resolved in all patients.

CONCLUSIONS

IFT often is associated with a systemic extracervical fibrotic process and tobacco use. Attempted thyroid resection often results in postoperative complications. Long-term follow-up showed no deaths from IFT and showed stability of the thyroiditis.

Riedel’s thyroiditis: impact and strategy of a challenging surgery

BACKGROUND

No surgical standard for Riedel's thyroiditis (RT) is established. Salvage surgery follows severe cervical and compressive airway symptoms or strong suspicion of malignancy. Obscured planes and multi-infiltrative extension prevent sufficient surgery with considerate complications. No alternative definitive treatment is available. In failing conservative treatment, the role of surgery in RT remains unclear.

MATERIALS AND METHODS

Clinical manifestation, treatment, outcome and follow-up in a unique series of eight consecutive patients with RT are presented.

RESULTS

Seven female patients and one male patient with cervical tumor growth or thyroiditis underwent four total and three sub-total thyroidectomies, respectively, one patient declined remedial surgery. Complications were one bilateral laryngeal nerve palsy and one transient hypoparathyroidism. Histology confirmed RT with perithyroidal extension and excluded malignancy in all. Symptomatic relief of cervical and airway obstruction was achieved in all. Follow-up revealed two extensive mediastinal RT recurrences 1 and 6 years after surgery.

CONCLUSION

Favourable symptomatic outcome and alleviation of steroids in the majority render surgery for RT valuable when conservative treatment fails. However, more radical procedures show no advantages and recurrences are not prevented. The demanding technique in RT requires special surgical expertise and highly recommends intra-operative neuromonitoring.