Expression of vascular endothelial growth factor in follicular cell-derived lesions of the thyroid: Is NIFTP benign or precancerous?

Objective: Vascular endothelial growth factor (VEGF) is an angiogenic factor that plays an important role in physiological and pathological angiogenesis of the thyroid. The aim of the current study was to determine the expression characteristics of VEGF in follicular cell-derived lesions of the thyroid and to assess whether a new entity noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is precancerous. Material and Methods: Patients diagnosed with 33 follicular adenomas (FA), 41 invasive follicular variant papillary thyroid cancer (IN-FVPTC), and 40 NIFTP in surgical resection materials were evaluated retrospectively. Immunostaining was performed on 5-µm paraffin tissue sections. The percentages of immunostaing for VEGF were evaluated on pathological materials. We used a percentage of labeled thyrocytes score (0, no labeling; 1, <30%; 2, 31-60%; 3, >60%) and an intensity score (0, no staining; 1, weak; 2, intermediate; 3, strong). The sum of two scores were accepted as the total score. Results: Mean ages of the FA, IN-FVPTC, and NIFTP groups were 44.7 ± 11.7 years, 46.9 ± 13.6 years, 43.2 ± 15.4 years, respectively and the mean VEGF immunostaining scores were 44.7 ± 29.3, 50.2 ± 32.54, 4 ± 26.3 respectively. Although there was no statistically significant difference (p= 0.347), the total score of the NIFTPs was higher than the scores of the FA (mean= 3.9 ± 1.8) and IN-FVPTC(mean= 4.3 ± 1.9) groups with a mean value of 4.6 ± 1.7. This result was remarkable. There was no statistically significant difference between tumor diameters and staining percentages (p= 0.750). Conclusion: Even if there were no statistical differences for VEGF immunostaining, it was high in NIFTPs. Since we know the role of VEGF in tumorigenesis, we can hypothesize that NIPTP can be precancerous. Our argue should be corroborated by a large prospective study.

Number of cells in parathyroid tissue in primary hyperparathyroidism cases and its relationship with serum calcium value.

BACKGROUND: The relationship between serum calcium (Ca) level to serum parathyroid hormone (PTH), phosphorus (P) levels and tissue properties of the parathyroid gland is unknown in primary hyperparathyroidism cases. Revealing this relationship may be useful for understanding the etiopathogenesis of primary hyperparathyroidism and determining the time of treatment. METHODS: Ninety patients (71 females, 19 males, age range; 27-73 years, average age; 46) who underwent single gland excision with the diagnosis of primary hyperparathyroidism were studied. The patients were divided into 2 groups as serum Ca level <12 and serum Ca level ≥12. Age and sex of the patients, mean cell number of the gland, mean volume of the gland, serum levels of PTH, P, and histopathologic type of hyperplasia were evaluated. RESULTS: The mean cell number per cubic centimeter is 22.9 (10-220 range) million in all glands. Serum Ca level was <12 in 82 (91.1%) of the patients, and ≥12 in 8 (8.9%) cases. Mean cell number of the gland, mean volume of the gland, existence of cystic hyperplasia of the gland, serum levels of PTH and P were statistically significant between the 2 groups (P < .001, P < .001, P < .05, P < .001, P < .05 respectively). CONCLUSION: In primary hyperparathyroidism cases serum Ca level is not related to age and sex but directly related to proportionals to the cell number and volume of the gland and serum levels of PTH, inversely related to cystic hyperplasia and serum levels of P. Early surgical intervention should be planned since the serum Ca level will be high in large adenomas with a noncystic radiological appearance.

Peptide Profile Differences of Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features, Encapsulated Follicular Variant, and Classical Papillary Thyroid Carcinoma: An Application of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

Introduction: The lack of papillary structures and faint and/or unclear core features of follicular variant of papillary thyroid carcinoma (FV-PTC) may hamper the definitive fine needle aspiration biopsy -based diagnosis. Recently, the nomenclature of noninvasive encapsulated FV-PTC was revised to "noninvasive follicular thyroid neoplasms with papillary-like nuclear features" (NIFTP). However, it remains inconclusive whether or not the peptide patterns differ between NIFTP and encapsulated FV-PTC. The main objectives of this study were to investigate the viability of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) in the pathological assessment of NIFTP and to evaluate the discriminatory power of MALDI MSI for the classification of classical variant of PTC (CV-PTC), NIFTP, and encapsulated FV-PTC. Methods: MALDI MSI was employed to investigate the changes in peptide profiles from 21 formalin-fixed paraffin-embedded (FFPE) tissue samples (n = 7 from each group of CV-PTC, NIFTP, and FV-PTC). Six out of seven FV-PTC FFPE tissue samples were encapsulated FV-PTC; only one was infiltrative FV-PTC. Liquid chromatography-tandem mass spectrometry was used for the identification of the peptide signals detected in MALDI MSI. Results: Using receiver operating characteristics analysis, 10 peptide signals distinguished NIFTP from normal thyroid parenchyma (area under the curve [AUC] >0.80). To evaluate the discriminatory power of MALDI MSI, statistically significant peptide signals (n = 88) within three groups were used for hierarchical clustering. The method had high discriminatory power for distinguishing CV-PTC from NIFTP and FV-PTC (encapsulated and infiltrative). The majority of the NIFTP and encapsulated FV-PTC were clustered together, indicating that NIFTP could not be distinguished from encapsulated FV-PTC. However, infiltrative FV-PTC FFPE tissue samples had the furthest distance from all the NIFTP cases. High signal intensities of S100-A6, vimentin, and cytoplasmic actin 1 were detected in FV-PTC, prelamin A/C in CV-PTC, and 60S ribosomal protein L6 and L8 in NIFTP tissues. Conclusions: MALDI MSI, a powerful tool combining histological and mass spectrometric data, enabled the differentiation of NIFTP from normal thyroid parenchyma. Although NIFTP is a recent definition that replaces noninvasive encapsulated FV-PTC, the peptide profiles of NIFTP and encapsulated FV-PTC were found to be similar.

Surgical approaches for papillary microcarcinomas: Turkey's perspective.

OBJECTIVES: The incidence of papillary microcarcinomas, which are defined as thyroid cancers of <10mm in size, has been increasing in the last decade. Herein, we present internet-based questionnaire results performed by the Turkish Association of Endocrine Surgery with the aim to evaluate the perspective of the management of papillary microcarcinomas in Turkey. MATERIAL AND METHODS: The user-friendly questionnaire consisted of 13 questions in total. These questions mainly addressed the surgical management of nodules and cancer of <1 cm in size. Patient management before, during, and after surgical intervention was also included; additionally, the "active surveillance approach" was questioned. RESULTS: There were 420 responders in total who were of multidisciplinary origin (endocrinologists, surgeons, nuclear medicine specialists, pathologists, and oncologists). Total thyroidectomy was the predominant treatment approach (65%) for the classical type of microcarcinoma limited in one lobe, whereas in cases of microcarcinomas incidentally diagnosed during hemithyroidectomy, complementary surgery approach was advised by 40% of the responders. The responders found capsule invasion (86%) and patient based management (94%) of high importance. The percentage of the responders who recommended radioactive iodine ablation in incidental cancers having no aggressive criteria was 51%. The survey participants that were against routine central dissection in these cases accounted for 73% of the responders. The recommendation of active surveillance (follow-up without any interventional therapy) was limited with 9% responders. CONCLUSION: The results of the questionnaire demonstrated that there have been various choices in Turkey for the surgical treatment of the papillary microcarcinomas.

Proteomic analysis reveals differential protein expression in variants of papillary thyroid carcinoma.

INTRODUCTION: Fine Needle Aspiration Biopsy (FNAB) allows the cytological differentiation of benign and malignant thyroid nodules. However, the method itself is not adequate in determining some cases. For example, the diagnosis of Follicular Variant Papillary Thyroid Carcinoma (FV-PTC) can be challenging. In the current study we investigate the protein profiles of FV-PTC and classical variant PTC (CV-PTC) with no lymph node metastasis and compare it with benign thyroid tissue. METHOD: We used CV-PTC (n = 6), FV-PTC (n = 6) and benign thyroid tissues (n = 6) to prepare tissue lysates. Proteins from each group were trypsin and lys-C digested. The samples were analyzed on a Q Exactive Orbitrap mass spectrometer. RESULTS: We identified 2560 proteins across all 18 specimens. Protein profiles revealed that there was no clear distinction between benign and FV-PTC samples. However, further examination of our data showed that proteins in energy metabolism have altered in FV-PTC. Proteomic pathway analysis showed marked alteration of the actin cytoskeleton proteins, especially several members of Arp2/3 complex were significantly increased in CV-PTC. We made the novel observation that IQGAP1 protein was significantly increased in CV-PTC, whereas IQGAP2 protein was highly expressed in FV-PTC lesions, suggesting differential roles of IQGAP proteins in thyroid pathology. CONCLUSION: In the present study, mass spectrometry based label free quantification approach was applied to investigate the protein profiles of FV-PTC, CV-PTC and benign thyroid tissues. This study pointed out that actin cytoskeleton proteins, IQGAP proteins and changes in energy metabolism play predominant roles in thyroid pathology.

BRAFV600E Mutation: Has It a Role in Cervical Lymph Node Metastasis of Papillary Thyroid Cancer?

BACKGROUND: The BRAFV600E mutation is common in papillary thyroid cancer (PTC). Lymph node metastasis (LNM) may be associated with poor prognosis. However, the LNM mechanism remains unclear. OBJECTIVES: Our aim was to evaluate the prevalence of the BRAFV600E mutation in primary tumors and accompanying LNM at the time of diagnosis. METHODS: This retrospective study included 51 PTC patients (40 women, 11 men; mean age 40.0 ± 16.5 years; range 6-81) who underwent total thyroidectomy accompanied by a lateral neck dissection due to preoperatively detected LNM. Real-time PCR was used for the detection of the BRAFV600E mutation in specimens from primary thyroid tumors and metastatic lymph node tumors. RESULTS: The prevalence of the BRAFV600E mutation was 64.7% (n = 33) in primary tumors and 47.1% (n = 24) in metastatic lymph nodes. Of 33 patients with BRAFV600E-positive primary tumors, 18 (54.5%) had BRAFV600E-positive metastatic lymph nodes. Of 18 patients with BRAFV600E-negative primary tumors, 6 (33.3%) had BRAFV600E-positive metastatic lymph nodes. The presence of the BRAFV600E mutation in the primary tumor did not affect the tumor size, but the diameter of metastatic lymph nodes significantly increased (by nearly 3 mm) with the presence of BRAFV600E in LNM (p = 0.01). CONCLUSIONS: In our study, the BRAFV600E mutation did not show a one-to-one correspondence. This indicates that the presence of BRAFV600E in the primary tumor is not clonal and addresses the role of intratumor heterogeneity in PTC tumorigenesis. This supports the theses that mutations occur in the later stages of tumorigenesis, might be subclonal, and develop de novo, or that some other factors may be involved in the development of metastasis.

Intraoperative ultrasonography is useful in surgical management of neck metastases in differentiated thyroid cancers.

Differentiated thyroid carcinomas are the most common malignancies of endocrine organs. Metastases to cervical lymph nodes occur in 20-50% of cases. Recurrence and survival rates are closely related to the type of surgery performed. High-resolution ultrasonography (USG) is a sensitive imaging method used to detect occult lymph node metastases in patients with thyroid cancer. We evaluated how intraoperative USG affected surgical success. This was a retrospective study comparing two groups of patients with thyroid carcinoma who underwent cervical lymph node dissection. A total of 101 patients (33 males and 68 females) were included. Group 1 included 53 patients who underwent surgery with intraoperative USG guidance. Group 2 included 48 patients who underwent surgery without the use of USG. All patients were followed up (mean 23 months; range 5-44 months) with thyroglobulin measurements and USG evaluations. Group 1 (intraoperative USG) had a residual/recurrent tumor rate of 1.9% (1/53 patients). Group 2 had a residual/recurrent tumor rate of 12.5% (6/48 patients). A statistically significant difference appeared between the residual/recurrent tumor rates in Groups 1 and 2 (p<0.05). In addition to its classical use in diagnosis and follow-up, intraoperative use of high-resolution USG can improve surgical success and may decrease the number of residual/recurrent tumors encountered during follow-up.

BRAF(V600E) mutation in Turkish patients with papillary thyroid cancer: strong correlation with indicators of tumor aggressiveness.

Papillary thyroid cancer (PTC) constitutes more than 90% of the thyroid cancers. MAP kinase/ERK pathway plays an important role in the development of several cancers. BRAF which is a member of Raf-kinase family activates this way. BRAF gene activating mutations lead to neoplastic transformation in thyroid follicle cells. In PTC, this mutation itself is a poor prognostic sign independent of other clinicopathological characteristics. We evaluated BRAF(V600E) mutation and clinical-pathological characteristics in Turkish population with PTC. We assessed 109 patients with PTC (88 female, 21 male). The average age was 38.7 ± 9.9 (17-71). BRAF(V600E) mutation was detected using polymerase chain reaction and fluorescent melting curve analysis. The results show that BRAF(V600E) mutation rate was found in 39.45% of our patients. We observed that BRAF(V600E) mutation was significantly higher in men, in tumors larger than 1 cm in size, and in patients with classical PTC. Moreover, statistically significant correlations of BRAF(V600E) with indicators of tumor aggressiveness such as thyroid capsular invasion, multifocality, lymph node metastasis, and extrathyroidal spread were found. Patient groups below and over the age of 45 did not differ in mutation frequency. Patients with micro-PTC were evaluated separately, it was found that BRAF(V600E) mutation was more frequent in the classic type and that lymph node metastasis rate significantly increased when the mutation was present. We concluded that BRAF(V600E) was correlated with indicators of tumor aggressiveness in our study population. This fact is taken into consideration in treatment and follow-up of our patients with PTC and positive BRAF(V600E) mutation.