Mildly Elevated Basal Calcitonin Level in Patients With Thyroid Goiter: Using the Calcitonin Measurement in Fine-Needle Aspirate Washout Fluid of the Healthy Lobe to Define Medullary Thyroid Cancer and Reactive C-Cell Hyperplasia

Background: Mildly elevated basal calcitonin level (bCT), that suggests a bCT increase up to 100 pg/ml, may testify either medullary thyroid carcinoma (MTC) or reactive thyroid C-cell hyperplasia (CCH). The latter is observed under many conditions such as hypercalcemia, hypergastrinemia, thyroiditis, neuroendocrine tumors (NET), renal end-stage kidney disease, obesity, and smoking. The research is aimed at analyzing the clinical significance of the calcitonin measurement in the fine needle aspiration washout fluid sample (FNA-CT) for screening certain patients with nodular thyroidopathy and elevated bCT. Patients and Methods: 70 patients with mildly elevated bCT (for women 6-100 pg/ml, for men 19-100 pg/ml) underwent ultrasound-guided FNA-CT measurement of the thyroid nodules and healthy lobe tissue. After obtaining a FNA-CT specimen, the needle was washed with 0.5 ml of saline solution. The calcitonin (CT) was measured by ECLIA (LIAISON XL). Results: There were 51 females and 19 males, with a mean age of 46.8 ± 14.4 years (range 16-81). The mean value of bCT was 23.3 ± 19 pg/ml (range: 7-86.5). According to ultrasound, 66 patients (95%) presented with thyroid nodules, in 4 cases previously identified nodes were not confirmed. The mean lesion size was 10.8 ± 4.9 mm (range: 4-26). Thyroid nodules were evaluated by FNA biopsy which revealed according to the Bethesda system category I in 6 cases, II - 44, III - 2, IV - 4, V - 6, and VI - 1. Analyzing FNA-CT results we identified 13 cases (18%) with MTC with low CT level of healthy lobe tissue (1-89.6 pg/ml) and high CT level of the lesion (>2000 pg/ml), which was confirmed by final histological examination. Low CT level from both healthy lobe and the nodule (<20 pg/ml) was observed in 10 cases, we carried out the measurement of stimulated CT to exclude the extrathyroidal CT production, which was confirmed in 1 case. All 4 patients with no nodules possessed significantly higher T-rates (1650-2000 pg/ml). The remaining 43 cases (61%) had an increased CT-level of healthy tissue (>2000 pg/ml) with a lower level from the lesion. Among these patients, the probable predisposing CCH factors were obesity - 8 cases, thyroiditis - 12, NET - 3, hypercalcemia - 3, renal kidney disease - 1, and smoking - 3. These 54 patients were kept under dynamic control. The observation period for patients - 1 year. 4 patients underwent surgical treatment, subsequently, histological examination revealed papillary thyroid cancer, follicular adenoma, colloid goiter against CCH, and CT-producing NET. Conclusion: The measurement of FNA-CT of the healthy lobe tissue may be useful to differentiate MTC and CCH, but requires new data in a major cohort of patients. The disadvantage of this study is the impossibility of CCH histological verification in the follow-up group.

Diagnostic Utility of INSM1 in Medullary Thyroid Carcinoma

Insulinoma-associated protein 1 (INSM1) is shown to be an excellent marker for neuroendocrine differentiation. However, the diagnostic utility of INSM1 in medullary thyroid carcinoma (MTC) has not yet been extensively investigated. INSM1 staining was performed on 21 MTCs, 7 MTC mimickers (including 3 papillary carcinomas, 2 poorly differentiated carcinomas, 1 follicular adenoma, and 1 nodular plasma cell hyperplasia), and 3 cases of C-cell hyperplasia. INSM1 staining of these cases was compared with the traditional MTC markers including calcitonin (CT), monoclonal carcinoembryonic antigen (mCEA), chromogranin A (CgA), and synaptophysin (Syn). The H-score was generated using the QuPath program, an open-source image analysis software. All 21 MTC cases and 3 C-cell hyperplasia cases were positive for all markers. The MTC mimickers were entirely negative for INSM1. INSM1 and Syn displayed, more consistently, high expression with minimal variability than CgA that showed a wide range of expression with significant variability. mCEA and CT exhibited mostly a high expression with some variability. Being a nuclear stain, interpretation was easier with INSM1 compared to other cytoplasmic markers. INSM1 is an excellent marker for neuroendocrine differentiation, entirely applicable in the diagnosis of MTC and C-cell hyperplasia with high sensitivity and specificity. In comparison with the traditional MTC markers, INSM1 is unique in the crisp nuclear staining pattern with a consistent, diffuse, and strong expression. INSM1 can be potentially combined with CT or mCEA as a dual stain, especially when the lesional tissue is limited for a panel of immunostains.

The Association of Myo-Inositol and Selenium Contrasts Cadmium-Induced Thyroid C Cell Hyperplasia and Hypertrophy in Mice

Previous studies have demonstrated that, in addition to inducing structural changes in thyroid follicles, cadmium (Cd) increased the number of C cells. We examined the effects of myo-inositol (MI), seleno-L-methionine (Se), MI + Se, and resveratrol on C cells of mice exposed to cadmium chloride (Cd Cl2), as no data are currently available on the possible protective effects of these molecules. In contrast, we have previously shown this protective effect against CdCl2 on the thyroid follicles of mice. Ninety-eight C57 BL/6J adult male mice were divided into 14 groups of seven mice each: (i) 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); (ii) Se (0.2 mg/kg/day per os); (iii) Se (0.4 mg/kg/day per os); (iv) MI (360 mg/kg/day per os); (v) Se (0.2 mg/kg/day) + MI; (vi) Se (0.4 mg/kg/day) + MI; (vii) resveratrol (20 mg/kg); (viii) CdCl2 (2 mg/kg/day i.p.) + vehicle; (ix) CdCl2 + Se (0.2 mg/kg/day); (x) CdCl2 + Se (0.4 mg/kg/day); (xi) CdCl2 + MI; (xii) CdCl2 + Se (0.2 mg/kg/day) + MI; (xiii) CdCl2 + Se (0.4 mg/kg/day) + MI; (xiv) CdCl2 + resveratrol (20 mg/kg). After 14 days, thyroids were processed for histological, immunohistochemical, and morphometric evaluation. Compared to vehicle, Cd significantly decreased follicle mean diameter, increased CT-positive cells number, area and cytoplasmic density, and caused the disappearance of TUNEL-positive C cells, namely, the disappearance of C cells undergoing apoptosis. Se at either 0.2 or 0.4 mg/kg/day failed to significantly increase follicular mean diameter, mildly decreased CT-positive cells number, area and cytoplasmic density, and was ineffective on TUNEL-positive C cells. Instead, MI alone increased significantly follicular mean diameter and TUNEL-positive cells number, and decreased significantly CT-positive cells number, area and cytoplasmic density. MI + Se 0.2 mg/kg/day or MI + Se 0.4 mg/kg/day administration improved all five indices more markedly. Indeed, follicular mean diameter and TUNEL-positive cells number increased significantly, while CT-positive cells number, area and cytoplasmic density decreased significantly. Thus, all five indices overlapped those observed in vehicle-treated mice. Resveratrol improved significantly all the considered parameters, with a magnitude comparable to that of MI alone. In conclusion, the association Myo + Se is effective in protecting the mouse thyroid from the Cd-induced hyperplasia and hypertrophy of C cells. This benefit adds to that exerted by Myo + Se on thyrocytes and testis.

Enzootic calcinosis in sheep in Uruguay: a brief review and report of two outbreaks

ABSTRACT: This study aimed to do a brief review of enzootic calcinosis in sheep and to report two outbreaks of Nierembergia rivularis poisoning in sheep in Uruguay. The outbreaks occurred in farms located on an island (Outbreak A) and on the border (Outbreak B) of the Rincón del Bonete lake. Sheep of all ages were affected, with the exception of suckling lambs. The first clinical signs occurred in early October, and deaths occurred from December to February. Outbreaks A and B had morbidity of 10%, and the mortality was 7.2% and 2.8% in Outbreaks A and B, respectively. The clinical signs included weight loss, retracted abdomen, stiff gait, and kyphosis. An autopsy was performed on one sheep from each outbreak. Pulmonary and arterial calcification, nephrocalcinosis, and osteopetrosis were observed in gross and microscopic examination in both sheep. Thyroid C-cell hyperplasia and carcinoma was observed in sheep A. Sheep B showed thyroid C-cell hyperplasia and parathyroid chief cell atrophy. The parathyroid was not examined in the sheep from Outbreak A. The differential diagnosis of enzootic calcinosis in southern South America should consider four toxic plants in the Solanaceae family: Solanum glaucophyllum, Solanum stuckertii, Nierembergia veitchii, and Nierembergia rivularis.

Effects of a Long-Term Administration of Aqueous Extract of Prunella vulgaris L. on Survival, Spontaneous Thyroid Carcinoma and Neoplastic C-cell Hyperplasia in Rats

Background: The continued global rise in thyroid carcinoma calls for alternative prevention and treatment strategies. Prunella vulgaris L. (PV) is a herbaceous plant with a medicinal property in the treatment of thyroid gland dysfunction, but its influence on thyroid carcinoma is unclear so far. This study was designed to investigate the effects of aqueous extract of PV on survival, spontaneous thyroid carcinoma and its preneoplastic lesion in rats.Methods: A total of 552 Wistar rats (half female and half male) were randomly assigned into 4 groups and given one of the following diets for 24 months: chow diet (control), 2.5 (low), 8.25 (middle) and 25 (high) g/kg bw PV diets. After intervention, serum metabolic parameters including indicators of liver and renal function, glucose and lipid profiles were measured. Histological examination was conducted to confirm the types of thyroid carcinoma and its preneoplastic lesion. Results: After intervention, serum aspartate transaminase of male rats in high PV group decreased significantly. No statistical differences among groups in terms of survival, body weight and other metabolic parameters were detected. In the control, low, middle and high PV groups, 14, 14, 15 and 8 rats developed thyroid carcinoma, respectively. Medullary thyroid carcinoma (MTC) emerged as the most common histological type in both sexes. Although PV failed to decrease risk of total thyroid carcinoma or each histological type, the incidence rates of neoplastic C-cell hyperplasia (CCH, a preneoplastic lesion of hereditary MTC) in PV groups were lower than that of control, and the lowest was observed in high PV group, manifesting as 5.25-time decrease in female rats and 5.5-time decrease in male rats.Conclusion: Our results suggested for the first time that, a long-term administration of aqueous extract of PV decreased the incidence of neoplastic CCH without impairing survival and metabolic parameters.

Ought to the Changes within the Immunophenotype of Solid Cell Nests (SCNs) and Follicular Cells in Hashimoto’s Thyroiditis be Considered as Premalignant Lesions?

Background: Papillary thyroid carcinoma (PTC) is more frequently reported in patients with Hashimoto’s thyroiditis (HT), which may be associated with the presence of solid cell nests (SCNs) and focal PTC-like nuclear alterations in the thyroid gland. The point of this consideration was to assess the morphological and immunohistochemical features of SCNs and follicular epithelial changes in Vietnamese patients with HT.Materials and methods: Hematoxylin – Eosin and immunohistochemistry were performed on 20 samples of HT patients who underwent thyroidectomy and were diagnosed with Hashimoto's thyroiditis at Military Medical Hospital 103 from 6/2018 to 6/2019. The expression of five markers (P63, Calcitonin, TTF1, CK19, and HBME-1) to be up-regulated in SCNs and follicular epithelial changes were evaluated.Results: 90% of samples had SCNs with an average of 10 SCNs per section. Only type 1 and type 4 of SCNs were presented (85% and 55%, respectively) and all SCNs were composed of main cells (p63-positive). 15 of 18 cases having SCNs possessed nuclear features of PTC. C-cell hyperplasia was found in one case with 20 clusters. All SCNs showed strong staining with CK19 and weak staining with HBME-1. Follicular epithelial changes were Hürthle cell metaplasia, PTC-like nuclear alterations, atypical solid nodules, papillary and glomerular-like forms (40%, 100%, 25%, and 50%, respectively). Follicular cells of glomerular-like forms (new alteration) especially were positive with CK19 (2 + ~ 3+), HBME-1 (1+), and TTF1, while the components in these follicles were negative with CK19, HBME-1, and TTF1. Among PTC-like nuclear alterations, all of the atypical solid nodules related to HT showed markers related to PTC and without SCNs.Conclusions: Increasing the number of SCNs, as well as PTC-like nuclear alterations of main cells in SCNs and follicular epithelial changes, which were co-expressed CK19 and HBME-1, may suggest precancerous changes in Hashimoto's thyroiditis.

MON-457 Reactive Thyroid C-Cell Hyperplasia or Medullary Thyroid Cancer in a Patient with Nodular Thyroidopathy. May the Calcitonin Measurement in Fine-Needle Aspirate Washout Fluid of the Healthy Lobe Help to Define These Conditions?

Background: Serum basal calcitonin (bCT) is used as a biomarker of medullary thyroid carcinoma (MTC) but bCT can also be elevated in patients with hypercalcemias, hypergastrinemias, thyroiditis, neuroendocrine tumors, renal end-stage kidney disease, obesity and cigarette smoking. The application of bCT and calcitonin measured in the FNA washout fluid sample (FNA-CT) for screening certain patients with nodular thyroidopathy can be controversial. Case: A 44 yo patient presented with elevated bCT level - 24pg/ml (N for male <18). He had a morbid obesity (BMI-45kg/m2) and thereby received GLP-1 receptor agonists Liraglutide 18 mg in total throughout one month. The ultrasound thyroid examination showed 2 nodules in the right lobe: 11mm and 9 mm (EU-TIRADS 2 and 4). Thyroid nodules were evaluated by fine needle aspiration biopsy (FNAB) which revealed benign colloid nodules (Bethesda II). Following the most updated ATA guidelines, to accurately diagnose MTC we performed FNA-CT measurement. The concentration from both nodules exceeded the upper reporting range of 2000 pg/ml. The patient stopped his therapy with Liraglutide and after one month of following, his bCT dropped at 18 pg/ml. He underwent a second workup with same results. We examined FNA-CT of contralateral healthy lobe and obtained 913 pg/ml. After this case, 17 patients with high-normal rate of bCT: 14 of them had a nodule (Bethesda II) and elevated FNA-CT of healthy tissue of the contralateral lobe (>2000 pg/ml) were determined in follow-up group. The remaining 3 patients with nodules (Bethesda IV-VI) and FNA-CT of healthy lobe which did not exceed bCT rate, were operated. MTC was confirmed. Discussion: Our patient had not only many factors which can occur his bCT level (obesity, smoking), but also unfavourable FNA washout results. Additionally, since in clinical studies GLP-1 receptor activation has been associated with C-cell hyperplasia (CCH), we cannot completely exclude the possible effect of this treatment on patient’s bCT level. We confronted a situation when, on the one hand, FNA-CT data indicate the MTC nature of hypercalcitoninemia, but on the other hand, decreasing bCT-level in dynamic observation is not common for MTC. FNAB of the healthy lobe and obtaining high rates of CT in the washout fluid sample allowed us to confirm the diffuse CCH process, thus to follow up these patients. CT stimulation test cannot distinguish between minimal MTC and CCH and has no reference range. The weak point of the proposed study is the lack of morphological data in the follow-up group of patients. Conclusion: It is possible to use rate of FNA-CT of the healthy lobe to differentiate between various C-cell diseases, but requires new data.