A CASE STUDY AND A CONCISE ACCOUNT OF RIEDEL'S THYROIDITIS

Riedel's thyroiditis (fibroinvasive thyroiditis) is a rare form of chronic inflammatory disease of the thyroid gland, characterized by progressive replacement of glandular tissue with fibrous tissue with spread into the capsule and surrounding tissues. The disease can lead to compression symptoms, such as difficulty breathing, pain when swallowing and compression of blood vessels and trachea. Diagnosis is based on clinical data and the results of instrumental studies, such as ultrasound (hypoechoic areas), scintigraphy, CT and MRI, as well as elastography, showing tissue rigidity. Riedel's thyroiditis is often associated with fibrosis of other organs (orbits, mediastinum, retroperitoneal space) and can be associated with IgG4-mediated inflammation, but an increase in IgG4 levels in the blood is not always observed. Despite the rarity of the disease, it represents a significant diagnostic and therapeutic problem, especially in the case of complications associated with compression of vital structures. The article discusses the clinical features, diagnostic methods and modern approaches to the treatment of Riedel's thyroiditis, as well as possible associations with other fibrosing diseases.