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Open access

Caroline Y. Hayashi, Danilo T. A. Jaune, Cristiano C. Oliveira, Bárbara P. Coelho, Hélio A. Miot, Mariângela E. A. Marques, José Vicente Tagliarini, Emanuel C. Castilho, Carlos Sp Soares, Flavia Rk Oliveira, Paula Soares, and Glaucia M.f.s Mazeto

Background: Thyroid nodules diagnosed as “Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance” (AUS/FLUS) or “Follicular Neoplasm/Suspected Follicular Neoplasm” (FN/SFN)”, according to Bethesda's classification, represent a challenge in clinical practice. Computerized analysis of nuclear images (CANI) could be a useful tool for these cases. Our aim was to evaluate the ability of CANI to correctly classify AUS/FLUS and FN/SFN thyroid nodules for malignancy.

Methods: We studied 101 nodules cytologically classified as AUS/FLUS (n=68) or FN/SFN (n=33) from 97 thyroidectomy patients. Slides with cytological material were submitted to manual selection and analysis of the follicular cell nuclei for morphometric and texture parameters using ImageJ software. The histologically benign and malignant lesions were compared for such parameters which were then evaluated for the capacity to predict malignancy using the Classification and Regression Trees Gini model. The Intraclass Coefficient of Correlation was used to evaluate method reproducibility.

Results: In AUS/FLUS nodule analysis, the benign and malignant nodules differed for Entropy (p<0.05), while the FN/SFN nodules differed for Fractal analysis, coefficient of variation (CV) of roughness, and CV-Entropy (p<0.05). Considering the AUS/FLUS and FN/SFN nodules separately, it correctly classified 90.0% and 100.0% malignant nodules, with a correct global classification of 94.1% and 97%, respectively. We observed that reproducibility was substantially or nearly complete (0.61-0.93) in 10 of the 12 nuclear parameters evaluated.

Conclusion: CANI demonstrated an high capacity for correctly classifying AUS/FLUS and FN/SFN thyroid nodules for malignancy. This could be a useful method to help increase diagnostic accuracy in the indeterminate thyroid cytology.

Open access

Flávia O Valentim, Bárbara P Coelho, Hélio A Miot, Caroline Y Hayashi, Danilo T A Jaune, Cristiano C Oliveira, Mariângela E A Marques, José Vicente Tagliarini, Emanuel C Castilho, Paula Soares, and Gláucia M F S Mazeto

Background

Computerized image analysis seems to represent a promising diagnostic possibility for thyroid tumors. Our aim was to evaluate the discriminatory diagnostic efficiency of computerized image analysis of cell nuclei from histological materials of follicular tumors.

Methods

We studied paraffin-embedded materials from 42 follicular adenomas (FA), 47 follicular variants of papillary carcinomas (FVPC) and 20 follicular carcinomas (FC) by the software ImageJ. Based on the nuclear morphometry and chromatin texture, the samples were classified as FA, FC or FVPC using the Classification and Regression Trees method.

Results

We observed high diagnostic sensitivity and specificity rates (FVPC: 89.4% and 100%; FC: 95.0% and 92.1%; FA: 90.5 and 95.5%, respectively). When the tumors were compared by pairs (FC vs FA, FVPC vs FA), 100% of the cases were classified correctly.

Conclusion

The computerized image analysis of nuclear features showed to be a useful diagnostic support tool for the histological differentiation between follicular adenomas, follicular variants of papillary carcinomas and follicular carcinomas.

Open access

Maurício Martins da Silva, Lueni Lopes Felix Xavier, Carlos Frederico Lima Gonçalves, Ana Paula Santos-Silva, Francisca Diana Paiva-Melo, Mariana Lopes de Freitas, Rodrigo Soares Fortunato, Leandro Miranda-Alves, and Andrea Claudia Freitas Ferreira

Bisphenol A (BPA) is the most common monomer in polycarbonate plastics and an endocrine disruptor. Though some effects of BPA on thyroid hormone (TH) synthesis and action have been described, the impact of this compound on thyroid H2O2 generation remains elusive. H2O2 is a reactive oxygen species (ROS), which could have deleterious effect on thyrocytes if in excess. Therefore, herein we aimed at evaluating the effect of BPA exposition both in vivo and in vitro on H2O2 generation in thyrocytes, besides other essential steps for TH synthesis. Female Wistar rats were treated with vehicle (control) or BPA 40 mg/kg BW for 15 days, by gavage. We then evaluated thyroid iodide uptake, mediated by sodium-iodide symporter (NIS), thyroperoxidase (TPO) and dual oxidase (DOUX) activities (H2O2 generation). Hydrogen peroxide generation was increased, while iodide uptake and TPO activity were reduced by BPA exposition. We have also incubated the rat thyroid cell line PCCL3 with 10−9 M BPA and evaluated Nis and Duox mRNA levels, besides H2O2 generation. Similar to that found in vivo, BPA treatment also led to increased H2O2 generation in PCCL3. Nis mRNA levels were reduced and Duox2 mRNA levels were increased in BPA-exposed cells. To evaluate the importance of oxidative stress on BPA-induced Nis reduction, PCCL3 was treated with BPA in association to N-acetylcysteine, an antioxidant, which reversed the effect of BPA on Nis. Our data suggest that BPA increases ROS production in thyrocytes, what could lead to oxidative damage thus possibly predisposing to thyroid disease.

Open access

Catarina Tavares, Maria João Coelho, Catarina Eloy, Miguel Melo, Adriana Gaspar da Rocha, Ana Pestana, Rui Batista, Luciana Bueno Ferreira, Elisabete Rios, Samia Selmi-Ruby, Bruno Cavadas, Luísa Pereira, Manuel Sobrinho Simões, and Paula Soares

Thyroid cancer therapy is based on surgery followed by radioiodine treatment. The incorporation of radioiodine by cancer cells is mediated by sodium iodide symporter (NIS) (codified by the SLC5A5 gene), that is functional only when targeted to the cell membrane. We aimed to evaluate if NIS expression in thyroid primary tumors would be helpful in predicting tumor behavior, response to therapy and prognosis. NIS expression was addressed by qPCR and immunohistochemistry. In order to validate our data, we also studied SLC5A5 expression on 378 primary papillary thyroid carcinomas from The Cancer Genome Atlas (TCGA) database. In our series, SLC5A5 expression was lower in carcinomas with vascular invasion and with extrathyroidal extension and in those harboring BRAFV600E mutation. Analysis of SLC5A5 expression from TCGA database confirmed our results. Furthermore, it showed that larger tumors, with locoregional recurrences and/or distant metastases or harboring RAS, BRAF and/or TERT promoter (TERTp) mutations presented significantly less SLC5A5 expression. Regarding immunohistochemistry, 12/211 of the cases demonstrated NIS in the membrane of tumor cells, those cases showed variable outcomes concerning therapy success, prognosis and all but one were wild type for BRAF, NRAS and TERTp mutations. SLC5A5 mRNA lower expression is associated with features of aggressiveness and with key genetic alterations involving BRAF, RAS and TERTp. Mutations in these genes seem to decrease protein expression and its targeting to the cell membrane. SLC5A5 mRNA expression is more informative than NIS immunohistochemical expression regarding tumor aggressiveness and prognostic features.