Discordance of serological and sonographic markers for Hashimoto’s thyroiditis with gold standard histopathology

Abstract

Objective To investigate the concordance of serologic and sonographic evidence of Hashimoto’s thyroiditis with its gold standard histopathologic identification. Design We performed a retrospective analysis on a cohort of 825 consecutive patients in whom TPOAb and thyroid ultrasound were performed, and in whom thyroid nodule evaluation led to surgical and histopathologic analysis. The presence or absence of Hashimoto’s thyroiditis on histopathology was correlated with serologic and sonographic markers. We further assessed the impact of low versus high titers of TPOAb upon this concordance. Results Of 825 patients, 277 (33.5%) had histologic confirmation of Hashimoto’s thyroiditis, 235 patients (28.4%) had elevated serum levels of TPOAb, and 197 (23.8%) had sonographic evidence of diffuse heterogeneity. Of those with histopathologic evidence, only 64% had elevated TPOAb (sensitivity: 63.9%; specificity: 89.4%), while only 49% were sonographically diffusely heterogeneous (sensitivity: 49.1%; specificity: 88.9%). A subset of only 102 of 277 (37%) with histologically proven Hashimoto’s thyroiditis was positive for both TPOAb and diffusely heterogeneous. Concordance analysis demonstrated that TPOAb and histopathology had higher agreement (κ = 0.55) than did ultrasound and histopathology (κ = 0.40) for the diagnosis of Hashimoto’s thyroiditis. Higher titers of TPOAb correlated with a higher likelihood of Hashimoto’s thyroiditis, with a best cutoff of 2.11-fold the upper normal level of TPOAb. Conclusion Only moderate concordance exists between serological evidence of Hashimoto’s thyroiditis and histopathologic findings, though it increases with higher TPOAb concentration. Diffuse heterogeneity on ultrasound is a less-sensitive diagnostic tool than elevated TPOAb.

An update on the pathogenesis of Hashimoto’s thyroiditis

“…A recent study of largely euthyroid patients with thyroid nodules found that the presence of TPO antibodies or diffuse heterogeneity on ultrasound examination showed high specificity (89.4% and 88.9%, respectively) but only moderate sensitivity (63.9% and 49.1%, respectively) in identifying histologically-defined coincidental HT [37]. The positive predictive value of TPO antibodies for the presence of HT was only 75%, reminding us that in the evolution of HT, circulating autoantibodies are not essential for disease initiation.…”

The Presence of Hypoechoic Micronodules in Patients with Hashimoto′s Thyroiditis Increases the Risk of an Alarming Cytological Outcome

“…Elevated TPOab are regarded as sensitive and an especially specific diagnostic tool in the case of HT. However, we are aware that an abnormal TPOab concentration may be found in healthy individuals, as well as in patients with Graves disease, and that US features of HT may precede TPOab positivity [2,3,37]. Our data show that the microscopic examination, which is regarded as a gold standard by some investigators, is not fully reliable either.…”

“…A combination of the above-mentioned methods brings the best sensitivity and specificity for diagnosing HT. However, the clinical, serological, and sonographic presentation is highly variable as all these features of HT are present concurrently in less than 30% of cases [1][2][3]. An elevated level of serum anti-thyroid peroxidase antibodies (TPOab) is widely considered to be the best serological marker of HT.…”

Influence Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: Hashimoto’s Thyroiditis Has a Weak Effect on Central or Lateral Lymph Node Metastasis

“…The serological or ultrasound evidence had a moderate concordance with the gold standard histological findings. 24 If pathological diagnoses were not performed and we had tissue in the tissue bank for that specific patient, we proceeded with a pathological diagnosis when TPOAb was 2.11-fold above the upper reference range value, which is the optimal cutoff, or when ultrasound showed a diffusely enlarged gland with a thickened isthmus and uneven internal echo.…”