Thyroid & parathyroid


Hashimoto thyroiditis

Last author update: 1 March 2009
Last staff update: 17 March 2023 (update in progress)

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PubMed Search: Hashimoto thyroiditis thyroid gland

Related Topics: Fibrous (fibrosing) variant

Shahid Islam, M.D., Ph.D.
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Cite this page: Islam S. Hashimoto thyroiditis. website. Accessed March 21st, 2023.
Definition / general
  • Autoimmune disease with goiter, elevated circulating antithyroid peroxidase and antithyroglobulin antibodies
  • First described by Hakaru Hashimoto in 1912 (World J Surg 2008;32:688)
  • Also called Hashimoto disease, struma lymphomatosa, lymphocytic thyroiditis
  • Hashitoxicosis: features of Hashimoto thyroiditis and Graves disease
Diagrams / tables

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Grading of thyroiditis on cytological material

Clinical features
  • Adults present with painless, gradual thyroid failure due to autoimmune destruction, may initially have transient hyperthyroidism
  • Children have variable hypothyroidism and reversion to euthyroidism so must monitor thyroid function (Clin Endocrinol (Oxf) 2009;71:451)
  • No female predominance in children with Down syndrome (Horm Res 2008;70:278)
  • Associated with HLA-DR5 (goitrous form), HLA-DR3 (atrophic form)
  • May coexist with SLE, rheumatoid arthritis, Sjögren syndrome, pernicious anemia, type 1 diabetes, Graves disease, chronic active hepatitis, adrenal insufficiency, MALT lymphoma of gastrointestinal tract (80:1 relative risk), other B cell lymphomas
  • Associated with well differentiated thyroid cancer (J Am Coll Surg 2007;204:764)
  • May evolve into thyroid lymphoma (J Clin Pathol 2008;61:438)
  • At thyroidectomy, cancer is common, even if not suspected preoperatively (Thyroid 2008;18:729)
  • Autoantibodies include:
    • Anti TSH (specific for Hashimoto and Graves disease)
    • Antithyroglobulin (less sensitive but similar specificity as antithyroid peroxidase, Clin Chem Lab Med 2006;44:837)
    • Antithyroid peroxidase (previously called antimicrosomal antibody, sensitive but not specific as 20% of adult women without disease have these antibodies); anti-iodine transporter (rare)
    • Note: anti TSH antibodies block the TSH receptor in Hashimoto disease but stimulate the TSH receptor in Graves disease
Radiology images

Contributed by Ayana Suzuki, C.T.

Isoechoic nodule

Case reports
  • Often no treatment needed, thyroid hormone for hypothyroidism (may remain euthyroid after 1 year when drug is withdrawn), subtotal thyroidectomy to relieve mass effect
  • Rarely progresses to lymphoma
Gross description
  • Diffuse symmetric enlargement of thyroid gland (25 - 250 g) with intact capsule, pyramidal lobe may be prominent
  • May have adhesions but thyroid gland is easily separated from other structures
  • Cut surface resembles lymph nodes with tannish yellow color
  • May have increased interlobular fibrosis or be fibrotic, particularly in elderly patients
  • Gland may atrophy
  • Occasionally gland is nodular or asymmetric
  • No necrosis or calcification
Gross images

Contributed by Mark R. Wick, M.D.

Various images

Large cell lymphoma

AFIP images

Symmetrical enlargement

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Atrophic gland

Nodular gland

Microscopic (histologic) description
  • Extensive lymphocytic infiltrate with germinal center formation
  • Lymphocytes are predominantly T cells and plasma cells (polyclonal)
  • Atrophic follicles with abundant Hürthle cells / oncocytes but no / reduced colloid
  • Fibrosis may be increased but does not extend beyond capsule
  • May see giant cells
  • Epithelium may have enlarged or overlapping nuclei with partial nuclear clearing, large squamous nests, hyperplastic follicles, ductal metaplasia (Am J Surg Pathol 2006;30:774)
  • Squamous metaplasia of follicular epithelium can be confused with solid cell nests (J Clin Endocrinol Metab 2012;97:2209)
  • Occasionally is nodular
  • Initial lesion is focal, then oxyphilic metaplasia of follicular cells and nodularity; later little thyroid parenchyma is present
Microscopic (histologic) images

Scroll to see all images.

Contributed by Andrey Bychkov, M.D., Ph.D.

Lymphoid follicles with germinal centers

Diffuse lymphoplasmacytic infiltration

Squamous metaplasia: p63+ cells in many follicles

Evolution of squamous metaplasia

Intense immunostaining

Lobulation of thyroid tissue by fibrotic bands

Vesicular nuclei of thyroid follicles similar to PTC nuclei

Aggregation of lyphoid follicles mimic thyroid nodule

Hashimoto thyroiditis with lymphoepithelial cyst

Nodular Hashimoto thyroiditis

Papillary microcarcinoma and Hashimoto thyroiditis

Contributed by Mark R. Wick, M.D.

Hashimoto thyroiditis

Branchial cyst-like change

With large cell lymphoma

Sclerosing variant

With marginal zone lymphoma

With sequestered thyroid nodule

AFIP images

Squamous lined cyst

Clear cell change

Clear nuclei

Circumscribed nodules

Benign follicular nodule

Images hosted on other servers:

Nodular gland with prominent lymphoid follicles

Atrophic thyroid follicles and prominent lymphoid follicles

Lymphoid follicle and prominent Hürthle cells

Lymphocytes, plasma cells, Hürthle cells and giant cells

Chronic inflammation and Hürthle cells

Oxyphilic degeneration of epithelium

follicles and
abundant colloid

Lymphoplasmacellular inflammation, destroyed follicles with sparse colloid, prominent Hürthle cells

With residual Graves disease

CD68+ giant cells

Antimicrosomal antibody

Antithyroglobulin antibody

Cytology description
  • Moderately cellular with aggregates of oncocytes (finely granular cytoplasm, large hyperchromatic nuclei, variable pleomorphism) and mature lymphocytes; also follicular cells, plasma cells, macrophages, neutrophils
  • Can grade based on lymphocytic infiltration from 0 to 3+ (see Diagrams / Tables section above), but does not correlate with clinical parameters (Cytojournal 2007;4:10)
Cytology images

Contributed by Ayana Suzuki, C.T.

Lymphocytes and oncocytes

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Oncocytic cells with atypical nuclei

Sheet of follicular cells with oncocytic change mixed with benign lymphoid cells

Resembles lymphoma

Grade I: mild lymphocytic inflammatory infiltrate

Grade II: moderate lymphocytic inflammation

Grade III: marked
inflammation with

ThinPrep versus Pap stain

Positive stains
Electron microscopy description
  • Oncocytic cells have many large mitochondria, reduced numbers of other organelles
Molecular / cytogenetics description

Thyroid: compare and contrast

Histopathology thyroid: Hashimoto thyroiditis

Differential diagnosis
Additional references
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