Localization and characterization of thyroid microcalcifications: A histopathological study

Calcium oxalate crystals as a cause of multiple punctate echogenic foci in benign thyroid lesions

PURPOSE

Multiple punctate echogenic foci (MPEF) on thyroid ultrasonography reflects psammoma bodies in papillary thyroid carcinomas. However, MPEF is also observed in benign thyroid lesions. The aim of this study was to determine the origin of MPEF in patients with benign thyroid lesions.

METHODS

We enrolled 26 patients with Graves' disease (GD) and 24 with follicular nodular disease (FND) who exhibited MPEF and underwent surgery. As controls, we enrolled 40 patients with GD and 32 with FND, but without MPEF, who underwent surgery.

RESULTS

MPEF was observed in both lobes in 80.8% of GDs with MPEF, but was limited to a single lobe in the remaining cases. MPEF was diffusely distributed in 72.3% of the cases and focally distributed in the remaining cases. On ultrasonography, most (92.3%) FNDs with MPEF were solid lesions, and seven nodules (26.9%) were interpreted as intermediate suspicion and their frequencies were higher than in those without MPEF (p < 0.01). Microscopically, calcium oxalate (CaOx) crystals were observed more frequently in GDs and FNDs with MPEF (100% and 88.5%, respectively) than in those without MPEF (p < 0.001). These differences were particularly significant for CaOx crystals > 100 μm. In GD cases, large CaOx crystals were observed more frequently in the lobes with MPEF than in those without (p < 0.05). No psammoma bodies were present in any of the cases.

CONCLUSION

Appearance of MPEF in GDs and FNDs is not because of psammoma bodies; it is attributable to CaOx crystals larger than 100 μm. Therefore, MPEF is not an indicator of malignancy.

The interplay between crystallinity and the levels of Zn and carbonate in synthetic microcalcifications directs thyroid cell malignancy

One of the key challenges in diagnosing thyroid cancer lies in the substantial percentage of indeterminate diagnoses of thyroid nodules that have undergone ultrasound-guided fine-needle aspiration (FNA) biopsy for cytological evaluation. This delays the definitive diagnosis and treatment plans. We recently demonstrated that hydroxyapatite microcalcifications (MCs) aspirated from thyroid nodules may aid nodule diagnosis based on their composition. In particular, Zn-enriched MCs have emerged as potential cancer biomarkers. However, a pertinent question remains: is the elevated Zn content within MCs a consequence of cancer, or do the Zn-enriched MCs encourage tumorigenesis? To address this, we treated the human thyroid cancer cell line MDA-T32 with synthetic MC analogs comprising hydroxyapatite crystals with varied pathologically relevant Zn fractions and assessed the cellular response. The MC analogs exhibited an irregular surface morphology similar to FNA MCs observed in cancerous thyroid nodules. These MC analogs displayed an inverse relationship between Zn fraction and crystallinity, as shown by X-ray diffractometry. The zeta potential of the non-Zn-bearing hydroxyapatite crystals was negative, which decreased once Zn was incorporated into the crystal. The MC analogs were not cytotoxic. The cellular response to exposure to these crystals was evaluated in terms of cell migration, proliferation, the tendency of the cells to form multicellular spheroids, and the expression of cancer markers. Our findings suggest that, if thyroid MCs play a role in promoting cancerous behavior in vivo, it is likely a result of the interplay of crystallinity with Zn and carbonate fractions in MCs.

Alteration Trend and Overlap Analysis of Positive Features in Different-Sized Benign and Malignant Thyroid Nodules: Based on Chinese Thyroid Imaging Reporting and Data System

Purpose

This study aimed to investigate the alteration trends and overlaps of positive features in benign and malignant thyroid nodules of different sizes based on the Chinese Thyroid Imaging Reporting and Data System (C-TIRADS).

Patients and Methods

1337 patients with 1558 thyroid nodules were retrospectively recruited from November 2021 to December 2023. These nodules were divided into three groups according to maximum diameter: A (≤10 mm), B (10-20 mm), and C (≥20 mm). C-TIRADS positive features were compared between benign and malignant thyroid nodules of different sizes. In addition, the trends of positive features with changes in nodule size among malignant thyroid nodules were analyzed.

Results

The incidence of positive features in malignant thyroid nodules was higher than that in benign. As benign nodules grow, the incidence of all positive features showed a linear decreasing trend (Z values were 72.103, 101.081, 17.344, 33.909, and 129.304, P values < 0.001). With the size of malignant thyroid nodules increased, vertical orientation, solid, marked hypoechogenicity, and ill-defined/irregular margins/extrathyroidal extension showed a linear decreasing trend (Z = 148.854, 135.378, 8.590, and 69.239, respectively; P values < 0.05), while suspicious microcalcifications showed a linear increasing trend (Z = 34.699, P<0.001). In terms of overlapping characteristics, group A had a significantly higher overlapping rate than the other two groups, and the overlapping rate of solid indicators remained the highest among all three groups (P < 0.05).

Conclusion

Differences in positive features were observed between thyroid nodules of different sizes. Except for suspicious microcalcifications, the incidence of other four positive features decreased with increasing nodule size. In addition, a negative correlation was observed between the overlap rate and nodule size. These results may provide a basis for sonographers to upgrade or downgrade thyroid nodules based on their own experience.

Ultrasonographic, clinical, and pathological features of papillary thyroid carcinoma in children and adolescents with or without Hashimoto's thyroiditis

Objective

To compare the ultrasonographic, clinical, and pathological features of children and adolescents with papillary thyroid carcinoma (PTC) with and without Hashimoto's thyroiditis (HT).

Materials and methods

A total of 52 children and adolescent patients surgically diagnosed with PTC between 2017 and 2022 were included; 14 children and adolescent patients with PTC were diagnosed with HT via pathological examination. The preoperative ultrasonographic, postoperative histological, and molecular and clinical characteristics were retrospectively analyzed.

Results

The prevalence rate of PTC in patients with HT was 27%. Papillary thyroid microcarcinomas were found in 11 of 38 patients without HT, but none in patients with HT (p = 0.023). Extrathyroidal extension, capsular invasion, and lymph node metastases were more frequent in patients with PTC and HT than in patients with PTC alone (p < 0.05 for both). The ultrasonographic features of nodule composition, echogenicity, shape, margin, Thyroid Imaging Reporting and Data System categories, and total points were similar. The patterns of echogenic foci were more prominent in the nodules of patients with HT than in those of patients without HT (p = 0.016).

Conclusion

The frequency of papillary thyroid microcarcinomas in patients with PTC and HT was less, whereas that of extrathyroidal extension, capsular invasion, and lymph node metastasis was significantly higher in patients with PTC and HT than in those with PTC alone. The patterns of echogenic foci on ultrasonography may represent a risk for PTC.

Zinc in microscopic calcifications isolated from thyroid fine needle aspiration may serve as a biomarker of thyroid nodule malignancy: A promising proof-of-concept

Thyroid nodules (TNs) are common neck ultrasonography (US) findings, yet only 5-10% of these nodules harbor thyroid cancer (TC). When US characteristics are consistent with an intermediate or high suspicion for TN malignancy, fine needle aspiration for cytology (FNAC) is indicated. The main limitation of FNAC is that cytological results can be indeterminate in up to 30% of cases, necessitating reevaluation through repeated FNAC, expensive molecular testing, or diagnostic thyroid lobe resection. As such, there is a need for further refinement of current diagnostic algorithms for TNs without subjecting patients to additional invasive procedures. As calcifications detected during thyroid US are considered a high-risk feature for malignancy, we used the material remaining following routine thyroid FNAC to isolate microscopic calcifications (MCs). We then characterized the elemental composition, morphology, and crystal phases of these MCs, ultimately revealing differences between the MCs from benign and malignant TNs. Specifically, thyroid MCs were identified as calcium phosphate crystals containing varying levels of magnesium, sodium, iron, and zinc. MCs obtained from malignant TNs, mainly papillary thyroid carcinoma, were composed of sub-micrometer spherical particles, whereas MCs from benign TNs consisted of faceted particles. While samples from most patients with a final diagnosis of malignant TNs (50% of them with indeterminate cytology) harbored zinc-containing MCs, zinc was largely absent in MCs from benign TNs (23% with indeterminate or non-diagnostic cytology). Together, these data suggest that the presence of zinc in MCs isolated from samples collected during routine FNAC may potentially offer value as a biomarker of TN malignancy. STATEMENT OF SIGNIFICANCE: As up to 40% of patients assessed for thyroid malignancy do not receive a definite diagnosis following thyroid nodule (TN) fine needle aspiration (FNA), there is a pressing need to improve the accuracy of current diagnostic algorithms. Chemical analyses of microscopic calcifications (MCs) may serve as a diagnostic target. We developed a straightforward protocol to chemically characterize MCs from excess material collected from TNs during routine FNA and found that these MCs differed between benign and malignant TNs. Specifically, zinc in TN-derived MCs may indicate a higher nodule malignancy risk, thus increasing the diagnostic accuracy of the FNA procedure, reducing the need for recurrent biopsies and diagnostic surgical procedures, and decreasing the costs, uncertainty, and stress faced by affected patients.

Sarcoidosis: Various Presentations, Coexisting Diseases and Malignancies

Sarcoidosis is a rare, chronic inflammatory disease with a characteristic non-caseating granuloma formation. It affects women more than men. The lung is the most commonly affected organ, however, extrapulmonary involvement is also seen. Sarcoidosis can affect any organ or tissue and can also involve multiple organs simultaneously. As a disease, it shares clinical symptoms with a variety of autoimmune, non-autoimmune disorders and malignancies. Not only it mimics clinically, but it also coexists with these diseases, posing a significant diagnostic challenge. During this literature review, we obtained data from the previously published PubMed articles within the last five years and reviewed the possible etiological association and clinical coexistence between sarcoidosis and other diseases/malignancies. We aimed to determine the common clinical manifestations, various complex presentations of sarcoidosis and pathophysiological considerations for the association, and to emphasize the link with other diseases, particularly thyroid disorders/malignancies. Physicians should be aware of these associated diseases and should always make a clinical suspicion when confronting a sarcoidosis patient. Thus, a comprehensive diagnostic evaluation for these associated conditions ought to be done in sarcoidosis patients to avoid any delay in the curative treatment for these coexisting diseases and to prevent substandard outcomes.

Value of Combining Clinical Factors, Conventional Ultrasound, and Contrast-Enhanced Ultrasound Features in Preoperative Prediction of Central Lymph Node Metastases of Different Sized Papillary Thyroid Carcinomas

Purpose

Early and accurate preoperative diagnosis of central lymph node metastasis (CLNM) is crucial to improve surgical management of patients with clinical lymph node-negative papillary thyroid carcinoma (PTC). Towards improving diagnosis of CLNM, we assessed the value of combining preoperative clinical characteristics, conventional ultrasound, and contrast-enhanced ultrasound (CEUS) in preoperative prediction of CLNM of different sized PTCs.

Patients and Methods

Patients were divided according to tumor size: a PTC group (>10 mm) and a papillary thyroid microcarcinoma (PTMC) group (≤10 mm). We retrospectively analyzed the clinical and ultrasonographic features of 120 PTC patients and 165 PTMC patients. Multivariate logistic regression analysis was used to screen independent risk factors and establish prediction models. Receiver operating characteristic curves were used to determine the best cut-off values for continuous variables and assess the performance of prediction models.

Results

Independent risk predictors of CLNM for the PTC group were extrathyroidal extension in CEUS (OR=7.923), tumor size >14 mm (OR=5.491), and multifocality (OR=3.235). For the PTMC group, the independent risk factors were the distance from the thyroid capsule =0 mm (OR=4.629), male (OR=3.315), tumor size >5 mm (OR=3.304), and microcalcification (OR=2.560). The predictive model of combined method had better performance in predicting CLNM of PTC compared with models based on CEUS and conventional ultrasound alone (area under the curve: 0.832 vs 0.739, P=0.0011; 0.832 vs 0.678, P=0.0012). For PTMC, comparing with CEUS, the combined method and conventional ultrasound performed better than CEUS alone in predicting CLNM (area under the curve: 0.783 vs 0.636, P=0.0016; 0.738 vs 0.636, P=0.0196).

Conclusion

The predictive models of combined method obtained from significant preoperative clinical and ultrasonographic features can potentially improve the preoperative diagnosis and individual treatment of CLNM in patients with PTC and PTMC. CEUS may be helpful in predicting CLNM of PTC, but CEUS would be ineffective in predicting CLNM of PTMC.

Molecular Aspects and Prognostic Significance of Microcalcifications in Human Pathology: A Narrative Review

The presence of calcium deposits in human lesions is largely used as imaging biomarkers of human diseases such as breast cancer. Indeed, the presence of micro- or macrocalcifications is frequently associated with the development of both benign and malignant lesions. Nevertheless, the molecular mechanisms involved in the formation of these calcium deposits, as well as the prognostic significance of their presence in human tissues, have not been completely elucidated. Therefore, a better characterization of the biological process related to the formation of calcifications in different tissues and organs, as well as the understanding of the prognostic significance of the presence of these calcium deposits into human tissues could significantly improve the management of patients characterized by microcalcifications associated lesions. Starting from these considerations, this narrative review highlights the most recent histopathological and molecular data concerning the formation of calcifications in breast, thyroid, lung, and ovarian diseases. Evidence reported here could deeply change the current point of view concerning the role of ectopic calcifications in the progression of human diseases and also in the patients' management. In fact, the presence of calcifications can suggest an unfavorable prognosis due to dysregulation of normal tissues homeostasis.

Local strong acids: A driving force for metastasis

Carcinogenesis was postulated as the result of the local buildup of strong acids such as hydrogenchloride which may trigger metastasis. A previous study revealed that bicarbonate raised tumor pH and suppressed metastases. The phosphate groups in DNA on neutrophil extracellular traps possess hydrogen bonding capacity and can accept protons. The proteins commonly found in neutrophil extracellular traps such as CCDC25, myeloperoxidase (MPO), histone H3, peptidylarginine deiminase 4 (PAD4) possess basic amino acid content at about 20.2%, 12.8%, 24.3% and 13.0% respectively, which attracts anions such as chloride. The striking 20.2% basic amino acid content in CCDC25 is similar to that of typical oncoproteins. Local hydrogenchloride may be the dominant impetus for metastasis, accounting for the anticancer effects of virtually all weak organic acids, acetic acid and lactic acid in particular.

On the chemical composition of psammoma bodies microcalcifications in thyroid cancer tissues

Recently the knowledge of chemical composition of pathological mineralizations is an important topic extensively studied because it could give more in-depth information to understand pathologies themselves and to improve prevention methods. In this work, psammoma bodies (PBs) microcalcifications in thyroid cancer tissue are investigated by different and complementary analytical methods as: micro-Fourier transformed spectroscopy, X-ray fluorescence spectroscopy, Inductively Coupled plasma Optical Emission Spectroscopy (ICP-OES) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy imaging (EDX). For the first time the micro-FTIR analysis of the only inorganic phase isolated from PBs was reported. Signals of the recorded spectrum showed that the main component of the calcifications is the amorphous carbonated calcium phosphate, and the IR spectrum of thyroid PBs is strongly consistent with that of PBs in human ovarian tumors. The XRF and the ICP analysis detected also the presence of iron ad zinc in thyroid PBs. These results are validated by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy imaging (EDX) carried out on tissue samples of the papillary thyroid carcinoma. By these analytical methods magnesium and sodium were detected within PBs while the presence of iron was confirmed by the Perls test. Summarizing the results of applied analytical methods, the main detected elements within the thyroid psammoma bodies are Ca, P, Mg, Na, Fe and Zn. Magnesium and sodium are found in malignant breast cancer microcalcifications, thus they seem correlated to neoplastic transformation. The Fe and Zn elements could give information about the origin of these pathological microcalcifications.