Riedel’s thyroiditis: A case report and review of the ultrasound findings of this rare disease entity

Riedel's thyroiditis is a difficult condition to diagnose due to rarity, varied presentation, with non-specific clinical, biochemical and radiographic findings which often mimic thyroid cancers. Definitive diagnosis of Riedel's thyroiditis requires histological analysis, and while fine-needle aspirations are typically insufficient, diagnostic samples can be taken with ultrasound-guided core biopsies.