Papillary microcarcinoma and adjacent Hashimoto thyroiditis

Symmetrical
enlargement with
lobular yellow
gray color (AFIP)

With large cell lymphoma

With large cell lymphoma

Thyroid gland
Thyroiditis
Hashimoto thyroiditis

Revised: 10 February 2017, last major update March 2009

Vesicular nuclei of thyroid follicles similar to PTC nuclei

Prominent
lymphoid follicles,
abundant colloid
in this section

Numerous large germinal centers

Hashimoto thyroiditis (or Hashimoto’s thyroiditis) is characterized by the destruction of thyroid cells by various cell- and antibody-mediated immune processes. It is the most common cause of hypothyroidism in the United States after age 6 years. Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs). [24] (See Etiology, Presentation, and Workup.)

By strict criteria, Hashimoto thyroiditis is a histologic diagnosis first described by Hakaru Hashimoto, a Japanese surgeon working in Berlin, Germany. His report, published in 1912, was based on the examination of 4 postoperative cases. He is also credited with introducing the term struma lymphomatosa in reference to the syndrome.

Elevated blood pressure (typically diastolic hypertension)

Other antithyroid antibodies found in AITD (including Hashimoto thyroiditis) include thyroid-stimulating antibody and cytotoxic antibody.

See Autoimmune Disorders: Making Sense of Nonspecific Symptoms, a Critical Images slideshow, to help identify several diseases that can cause a variety of nonspecific symptoms.

Hashimoto thyroiditis is part of the spectrum of autoimmune thyroid diseases (AITDs) and is characterized by the destruction of thyroid cells by various cell- and antibody-mediated immune processes. This condition is the most common cause of hypothyroidism in the United States in individuals older than 6 years. [24]

Total and fractionated lipid profile: Possibly elevated total cholesterol, LDL, and triglyceride levels in hypothyroidism

Cosmetic reasons (eg, large, unsightly goiters)

Other variants of AITD include the following conditions:

  • diffusely enlarged thyroid gland with a heterogeneous echotexture is a common sonographic presentation 6
  • the presence of hypoechoic micronodules (1-6 mm) with surrounding echogenic septations is also considered to have a relatively high positive predictive value 3,4 . This appearance may be described as pseudonodular or a giraffe pattern
  • colour Doppler study usually shows normal or decreased flow, but occasionally there might be hypervascularity similar to a thyroid inferno
  • prominent reactive cervical nodes may be present, especially in level VI, but they have normal morphologic features
  • patients are at higher risk for papillary thyroid carcinoma, so a discrete nodule should be considered for biopsy

It is difficult to reliably sonographically differentiate Hashimoto thyroiditis from other thyroid pathology. Ultrasound features can be variable depending on the severity and phase of disease 1,5 :

5%) can present with hyperthyroidism (a.k.a. Hashithyrotoxicosis (Htx)). There is often a gradual painless enlargement of the thyroid gland during the initial phase with atrophy and fibrosis later on in the course.

In some situations, large nodules may be present, which may be referred to as nodular Hashimoto thyroiditis 10 .

Typically affects middle-aged females (30-50 year age group with an F:M ratio of 10-15:1).

Hashimoto thyroiditis (HT), also known as lymphocytic thyroiditis or chronic autoimmune thyroiditis, is a subtype of autoimmune thyroiditis. It is one of the most common thyroid disorders.

  • lymphocytic aggregates
  • transformed follicular cells (Askanazy/oxyphilic/Hurthle cells)

70% of cases 2

  • thyroid peroxidase antibodies (TPO): found in 90-95% of cases 2
  • Later stages show superadded fibrosis.