Can Serum Thyroglobulin Levels Help to Identify the Involved Neck Compartment of Differentiated Thyroid Carcinoma?

We aimed to evaluate the predictive ability of serum thyroglobulin (Tg) levels on the localization of the metastatic lymph node compartments in locoregional metastases of papillary thyroid cancer (PTC). This retrospective study included 143 patients who underwent neck dissections for a total of 172 for persistent/recurrent locoregional PTC. They were grouped according to the localization of lymph node metastasis (LNM): Central (C-LNM), Lateral (L-LNM), both central and lateral LNM (C+L LNM). To confirm that the Tg cutoff discriminated LNM localizations, the sample was categorized as suppressed (<0.1 mU/l) or non-suppressed (>0.1 mU/l) according to TSH and ROC analysis. Mixed-effects models were used to investigate the effect of LNM localization on Tg levels and to eliminate the confounding effects of TSH, tumor burden (defined as the number and the largest diameter of LNM), and RAI. Mean Tg levels were 1.43 µg/l for C-LNM (n=47), 3.7 µg/l for L-LNM (n=99), and 8.60 µg/l for C+L LNM (n=26). Independent of TSH, tumor burden and RAI, the mean Tg levels of L-LNM and C+L LNM groups were not significantly different, while that of C-LNM was significantly lower than those of L-LNM and C+L LNM. To discriminate C-LNM from L-LNM and C+L LNM in patients with TSH>0.1 mU/l, the optimal cutoff for Tg was 1.05 µg/l (sensitivity=74.7%, specificity=70.4%, PPV=87.7%). L-LNM increases serum Tg levels more than C-LNM in persistent/recurrent locoregional nodal disease of PTC. Tg above 1.05 µg/l may indicate lateral LNM. Tg may be an important marker for the localization of LNM in the neck.

Is lifelong follow-up necessary for low-risk papillary thyroid carcinoma? Case series and a review of the literature.

ABSTRACT: Late recurrences of papillary thyroid carcinoma (PTC) are seen rarely, especially for low-risk PTC. However, there are cases of late metastasis described in the literature, even four decades after the first treatment. We presented three low-risk PTC cases with late recurrences. In the first case, recurrence with distant organ metastasis without locoregional disease occurred 36 years after the first treatment. Recurrences in second and third cases were seen with lateral neck metastasis without central (skip metastasis), 17 and 10 years after the primary treatment. Initial treatment was ideal, and all three were followed with a complete response for years, after recurrences were diagnosed and appropriate treatments were administered. Increasing frequency of low-risk PTC increases medical costs of these patients. Thus, some suggest shortening the follow-up period not only because the increasing health burden but also because of the rarity of late recurrences as well. Some authors suggest that dynamically risk-stratified (DRS) low-risk thyroid cancer patients having excellent response to treatment after 5 years of follow-up can be discharged to primary care. Primary care facilities may follow patients with unmeasurable Thyroglobulin (Tg) levels; however, our cases suggest continuing thyroglobulin measurements (annual or at least every few years) for the exceptional but possible late recurrences.

Primary hyperparathyroidism and sarcoma: A case report and literature review.

ABSTRACT: The relationship between primary hyperparathyroidism (PHPT) and bone sarcoma is debatable, especially after wider use of teriparatide treatment, concerns have intensified on the issue. Extensive search in English literature revealed 10 cases reported having PHPT and sarcomas. Besides, three cases of bone sarcoma occurring after teriparatide treatment had been reported. Hereby, we report a 51-year-old woman with a prolonged history of PHPT. She was diagnosed with chondrosarcoma 9 years after refusal and lack of treatment for PHPT. She was cured surgically for both chondrosarcoma and parathyroid adenoma at 1-year interval. So far, large cohorts did not show an increase in the incidence of bone sarcomas in PHPT. Several case observations, including the current one, as well as data from in vitro and rat studies, pointed out prolonged parathormone exposure, may be a risk for bone sarcomas. Under these circumstances, a safer attitude on individual basis would be the prevention of prolonged parathormone exposures.

Long-term effects of radioiodine treatment on thyroid functions and ultrasonographic features in patients with toxic adenoma and toxic multinodular goitre.

OBJECTIVE: This study aimed to investigate the long-term effect of radioiodine (RAI) treatment on thyroid functions and ultrasonographic changes in the thyroid gland and toxic nodules. METHODS: Thyroid function tests and ultrasonography reports of patients diagnosed with toxic adenoma (TA) or toxic multinodular goitre (TMNG) between 2000 and 2021 were retrospectively analysed. RESULTS: We included 100 patients whom thyroid function and ultrasonography results were obtained from our outpatient clinic before and at least 36 months post-RAI. At the end of the follow-up period, the mean thyroid volume reduction in patients with TA and TMNG was 56.6% ± 3.1% and 51.1% ± 6.7%, respectively; the mean volume decrease of all toxic nodules was 80.5% ± 1.9%. The volume of the thyroid and toxic nodules was significantly reduced up to 12 years (p < 0.01). Between 3 and 10 years after RAI therapy, the annual incidence of hypothyroidism was 2.0% and 1.5% in the TA and TMNG groups, respectively. Toxic nodules were more frequently solid and hypoechoic in post-RAI ultrasounds (p < 0.01). CONCLUSIONS: The volume of thyroid gland and toxic nodules continuously decreases, as the risk of hypothyroidism increases up to 10 years after RAI treatment. After RAI treatment, patients should be followed up to check their thyroid functions. In post-RAI examinations, toxic nodules may show ultrasonographic features suspicious for malignancy. History taking should include previous RAI therapies and old scintigraphy scans should be evaluated to avoid unnecessary procedures and non-diagnostic biopsy results.

The sonographer's and pathologist's perspective of echogenic microfoci in papillary thyroid carcinoma.

Objective: Punctate echogenic foci (PEF)/microcalcifications are thought to represent psammoma bodies (PB) in histopathology. However, there are few and contradictory data on this. Different types of sonographic echogenic microfoci (EMF) are seen in papillary thyroid carcinoma (PTC), and their histopathological equivalents are not clearly known. There is also conflicting data on the interobserver agreement between the sonographers on EMF. Methods: We prospectively collected US video records of PTC nodules with and without EMF in two large thyroid centers. All video recordings were independently interpreted by three blinded, experienced sonographers. EMF were classified as true microcalcifications (punctate echogenic foci (PEF) ≤1 mm long), linear microechogenities (>1 mm long, posterior acoustic enhancement of the back wall of a microcystic area), comet-tail artifacts/reverberations or linear microechogenities with comet-tail artifacts/reverberations, non-shadowing coarse echogenic foci (>1 mm nonlinear areas) and unclassifiable. Histopathological evaluation was performed by two blinded, qualified pathologists. Results: A total of 114 malignant nodules were included. The average Cohen's kappa (κ) of three sonographers for the EMF presence was 0.775, indicating substantial agreement. A substantial agreement for PEF with 0.658 κ, only fair agreement for other types of EMF with 0.052 to 0.296 κ were detected. EMF were significantly associated with PB and papillae. PEF had an evident relationship with PB in multivariate analysis. There was a strong positive correlation between the amount of PEF and PB (r = 0.634, P < 0.001). Conclusions: PEF in PTC mainly correspond to PB on histopathology. Although observation of EMF varies among sonographers, this inconsistency can be reduced by classifying EMF into subgroups and keeping the term 'PEF' only for true microcalcifications.

Subacute THYROiditis Related to SARS-CoV-2 VAccine and Covid-19 (THYROVAC Study): A Multicenter Nationwide Study.

CONTEXT: The aims of the study are to compare characteristics of subacute thyroiditis (SAT) related to different etiologies, and to identify predictors of recurrence of SAT and incident hypothyroidism. METHODS: This nationwide, multicenter, retrospective cohort study included 53 endocrinology centers in Turkey. The study participants were divided into either COVID-19-related SAT (Cov-SAT), SARS-CoV-2 vaccine-related SAT (Vac-SAT), or control SAT (Cont-SAT) groups. RESULTS: Of the 811 patients, 258 (31.8%) were included in the Vac-SAT group, 98 (12.1%) in the Cov-SAT group, and 455 (56.1%) in the Cont-SAT group. No difference was found between the groups with regard to laboratory and imaging findings. SAT etiology was not an independent predictor of recurrence or hypothyroidism. In the entire cohort, steroid therapy requirement and younger age were statistically significant predictors for SAT recurrence. C-reactive protein measured during SAT onset, female sex, absence of antithyroid peroxidase (TPO) positivity, and absence of steroid therapy were statistically significant predictors of incident (early) hypothyroidism, irrespective of SAT etiology. On the other hand, probable predictors of established hypothyroidism differed from that of incident hypothyroidism. CONCLUSION: Since there is no difference in terms of follow-up parameters and outcomes, COVID-19- and SARS-CoV-2 vaccine-related SAT can be treated and followed up like classic SATs. Recurrence was determined by younger age and steroid therapy requirement. Steroid therapy independently predicts incident hypothyroidism that may sometimes be transient in overall SAT and is also associated with a lower risk of established hypothyroidism.