Citation, DOI & article data
Hashimoto thyroiditis, also known as lymphocytic thyroiditis or chronic autoimmune thyroiditis, is a subtype of autoimmune thyroiditis. It is one of the most common thyroid disorders.
Typically affects middle-aged females (30-50 year age group with an F:M ratio of 10-15:1).
Patients usually present with hypothyroidism +/- goiter. However, a very small proportion of cases (~5%) can present with hyperthyroidism (also known as Hashitoxicosis). There is often a gradual painless enlargement of the thyroid gland during the initial phase with atrophy and fibrosis later on in the course.
The Hashitoxicosis phase, if present, usually only lasts 1-2 months. Although rare cases last much longer 16.
There is autoimmunity to the thyroid gland which bears both humoral- and cell-mediated features. This is followed by lymphocytic infiltration of the thyroid gland with lymphoid follicles replacing thyroid follicles. This may affect the thyroid gland in either a diffuse or focal manner. Cell populations include:
transformed follicular cells (Askanazy/oxyphilic/Hurthle cells)
Later stages show superadded fibrosis.
antithyroglobulin antibodies: found in ~70% of cases 2
thyroid peroxidase antibodies (TPO): found in 90-95% of cases 2
Hashimoto encephalopathy (rare)
other autoimmune disorders
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:
diffusely enlarged thyroid gland with a heterogeneous echotexture is a common sonographic presentation (especially initial phase) 6
the glands may be atrophic and small in chronic cases.
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
color Doppler study usually shows normal or decreased flow, but occasionally there might be hypervascularity similar to a thyroid inferno
the hypervascularity does not reflect thyrotoxicosis, indeed it appears to be more common in hypothyroid Hashimoto patients 11
prominent reactive cervical nodes may be present, especially in level VI, but they have normal morphologic features
In some situations, large nodules may be present, which may be referred to as nodular Hashimoto thyroiditis 10.
early stages: may show increased uptake
late stages: single or multiple areas of reduced uptake (cold spots)
diffuse high uptake throughout the thyroid is consistent with chronic thyroiditis (or a normal variant) 14,15
superimposed focal high uptake should raise concern for a thyroid nodule including the possibility of carcinoma
History and etymology
It was first described in 1912 by Hakaru Hashimoto (1881-1934), a Japanese physician 7 while working in Germany; in his original description, he called it 'struma lymphomatosa' 13.
patients are at higher risk for papillary thyroid carcinoma, so a discrete nodule should be considered for biopsy
For ultrasound appearances consider:
- 1. Langer J, Khan A, Nisenbaum H et al. Sonographic Appearance of Focal Thyroiditis. AJR Am J Roentgenol. 2001;176(3):751-4. doi:10.2214/ajr.176.3.1760751
- 2. Intenzo CM, Capuzzi DM, Jabbour S et-al. Scintigraphic features of autoimmune thyroiditis. Radiographics. 21 (4): 957-64. Radiographics (full text) - Pubmed citation
- 3. Yeh H, Futterweit W, Gilbert P. Micronodulation: Ultrasonographic Sign of Hashimoto Thyroiditis. J Ultrasound Med. 1996;15(12):813-9. doi:10.7863/jum.1922.214.171.1243
- 4. Set PA, Oleszczuk-raschke K, Von lengerke JH et-al. Sonographic features of Hashimoto thyroiditis in childhood. Clin Radiol. 1996;51 (3): 167-9. - Pubmed citation
- 5. Moon H, Kim E, Kim M, Kwak J. Lymphocytic Thyroiditis on Fine-Needle Aspiration Biopsy of Focal Thyroid Nodules: Approach to Management. AJR Am J Roentgenol. 2009;193(4):W345-9. doi:10.2214/ajr.09.2413
- 6. Takashima S, Matsuzuka F, Nagareda T et-al. Thyroid nodules associated with Hashimoto thyroiditis: assessment with US. Radiology. 1992;185 (1): 125-30. Radiology (abstract) - Pubmed citation
- 7. H. Hashimoto: Zur Kenntnis der lymphomatösen Veränderung der Schilddrüse (Struma lymphomatosa). Archiv für klinische Chirurgie, Berlin, 1912, 97: 219−248.
- 8. Takashima S, Fukuda H, Tomiyama N, Fujita N, Iwatani Y, Nakamura H. Hashimoto Thyroiditis: Correlation of MR Imaging Signal Intensity with Histopathologic Findings and Thyroid Function Test Results. Radiology. 1995;197(1):213-9. doi:10.1148/radiology.197.1.7568826
- 9. Vitti P, Rago T, Mazzeo S et al. Thyroid Blood Flow Evaluation by Color-Flow Doppler Sonography Distinguishes Graves' Disease from Hashimoto's Thyroiditis. J Endocrinol Invest. 1995;18(11):857-61. doi:10.1007/BF03349833
- 11. Chaudhary V & Bano S. Thyroid Ultrasound. Indian J Endocr Metab. 2013;17(2):219. doi:10.4103/2230-8210.109667
- 12. Schaffer A, Puthenpura V, Marshall I. Recurrent Thyrotoxicosis Due to Both Graves’ Disease and Hashimoto’s Thyroiditis in the Same Three Patients. Case Reports in Endocrinology. 2016;2016:1-4. doi:10.1155/2016/6210493
- 13. Sawin C. The Heritage of Dr. Hakaru Hashimoto (1881-1934). Endocr J. 2002;49(4):399-403. doi:10.1507/endocrj.49.399
- 14. Chen Y, Chen Y, Cheng R, Yeh C, Lee C, Hsu C. The Significance of FDG Uptake in Bilateral Thyroid Glands. Nucl Med Commun. 2007;28(2):117-22. doi:10.1097/mnm.0b013e328013eaf7
- 15. Tsubaki F, Kurata S, Tani J, Sumi A, Fujimoto K, Abe T. Clinical Significance of Patterns of Increased [18F]-FDG Uptake in the Thyroid Gland: A Pictorial Review. Jpn J Radiol. 2017;36(3):181-93. doi:10.1007/s11604-017-0715-y
- 16. Shahbaz A, Aziz K, Umair M, Sachmechi I. Prolonged Duration of Hashitoxicosis in a Patient with Hashimoto’s Thyroiditis: A Case Report and Review of Literature. Cureus. 2018;10(6). doi:10.7759/cureus.2804
- 17. Anderson L, Middleton W, Teefey S et al. Hashimoto Thyroiditis: Part 1, Sonographic Analysis of the Nodular Form of Hashimoto Thyroiditis. AJR Am J Roentgenol. 2010;195(1):208-15. doi:10.2214/ajr.09.2459 - Pubmed
- 18. Anderson L, Middleton W, Teefey S et al. Hashimoto Thyroiditis: Part 2, Sonographic Analysis of Benign and Malignant Nodules in Patients With Diffuse Hashimoto Thyroiditis. AJR Am J Roentgenol. 2010;195(1):216-22. doi:10.2214/ajr.09.3680