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.