Pattern Recognition: Diffuse Thyroid Disease

Abstract

Diffuse enlargement of the thyroid gland is a common finding during both physical examination and during ultrasound evaluation. While chronic lymphocytic thyroiditis (CLT), Hashimoto’s thyroiditis, is the most common cause of goiter and hypothyroidism in countries with adequate iodine intake, thyroiditis refers to a diverse group of conditions caused by thyroid inflammation. The sonographic hallmark of thyroid autoimmunity is diffuse hypoechogenicity and heterogeneity, with multiple variants having been described. Understanding the various features of thyroiditis provides valuable clinical insight into the disease process. Moreover, pattern recognition of the various sonographic presentations of autoimmune diffuse thyroid disease is essential in determining if a focal abnormality represents a true nodule which may require fine-needle aspiration biopsy or is simply part of the inflammatory process. Doppler interrogation of the thyroid in a patient with thyrotoxicosis can often differentiate Graves’ disease from silent or subacute thyroiditis. Reactive appearing lymph nodes in the paratracheal and adjacent lateral neck regions are common in thyroiditis. Real-time imaging or the use of cine-clips is superior to static imaging in detecting diffuse thyroid disease and ideally is performed by the clinician caring for these patients. As such, this chapter includes electronic supplementary material (ESM).