Challenge in the Pathological Diagnosis of the Follicular- Patterned Thyroid Lesions.

BACKGROUND: The follicular-patterned thyroid lesions (FPTLs) include hyperplastic nodules (HN), follicular adenoma (FA), non-invasive follicular neoplasm with papillary-like nuclear features (NIFTP), follicular carcinoma (FC), and the follicular variant of papillary carcinoma (FVPTC). Sometimes the pathologists cannot accurately separate these lesions from each others on a histological basis. AIMS: To evaluate the utility of immunohistochemistry in the diagnosis of FPTLs. MATERIALS AND METHODS: Immunohistochemical analysis, incorporating 83 cases of histologically confirmed FPTLs out of which 20 carcinomas, 51 benign FPTLs (38 HN and 13 FA), and 12NIFTP were separated from each others using four immunostains (HBME-1, CK19, Galectin-3, and CD56). RESULTS: We found statistically significantly more frequent expression of HBME-1, CK19, Galectin-3 proteins in carcinomas as compared to benign FPTLs (p = <0.01). HBME-1 and Galectin-3 were the most sensitive markers for the diagnosis of malignant FPTLs (75%). Galectin-3 was the most specific marker for the diagnosis of carcinoma (90.3%). CONCLUSIONS: The histomorphological features remain the cornerstone of the diagnosis of FPTN. Although HBME-1, Galectin-3, and CK19 immunostains have some diagnostic value in the separation of malignant from benign FPTLs, they are variably expressed in the benign and malignant FPTLs. No single immunostain has sufficient sensitivity and specificity and therefore their diagnostic use is controversial. Future studies are mandated to find more reliable markers that can separate between benign and malignant FPTLs.

Objective analysis of collagen organization in thyroid nodule capsules using second harmonic generation microscopy images and the Hough transform.

Papillary carcinoma is the most prevalent type of thyroid cancer. Its diagnosis requires accurate and subjective analyses from expert pathologists. Here we propose a method based on the Hough transform (HT) to detect and objectively quantify local structural differences in collagen thyroid nodule capsules. Second harmonic generation (SHG) microscopy images were acquired on non-stained histological sections of capsule fragments surrounding the healthy thyroid gland and benign and tumoral/malignant nodules. The HT was applied to each SHG image to extract numerical information on the organization of the collagen architecture in the tissues under analysis. Results show that control thyroid capsule samples present a non-organized structure composed of wavy collagen distribution with local orientations. On the opposite, in capsules surrounding malignant nodules, a remodeling of the collagen network takes place and local undulations disappear, resulting in an aligned pattern with a global preferential orientation. The HT procedure was able to quantitatively differentiate thyroid capsules from capsules surrounding papillary thyroid carcinoma (PTC) nodules. Moreover, the algorithm also reveals that the collagen arrangement of the capsules surrounding benign nodules significantly differs from both the thyroid control and PTC nodule capsules. Combining SHG imaging with the HT results thus in an automatic and objective tool to discriminate between the pathological modifications that affect the capsules of thyroid nodules across the progressions of PTC, with potential to be used in clinical settings to complement current state-of-the-art diagnostic methods.

A Novel Diagnostic Method for Thyroid Follicular Tumors Based on Immunofluorescence Analysis of p53-Binding Protein 1 Expression: Detection of Genomic Instability.

Background: The preoperative diagnosis of thyroid follicular carcinomas (FCs) by fine-needle aspiration cytology is almost impossible. It was previously demonstrated that p53-binding protein 1 (53BP1) expression, based on immunofluorescence (IF), can serve as a valuable biomarker to estimate the malignant potential of various cancers. 53BP1 belongs to a class of DNA damage response molecules that rapidly localize to the site of DNA double-strand breaks, forming nuclear foci (NF). This study aimed to elucidate the utility of 53BP1 NF expression as a biomarker to differentiate follicular tumors (FTs). Methods: Associations between 53BP1 expression based on IF and histological types of FTs were analyzed using 27 follicular adenomas (FAs), 28 minimally invasive FCs, and 14 widely invasive FCs. Furthermore, the study clarified the relationship between 53BP1 NF and copy number aberrations (CNAs) based on array comparative genomic hybridization, a hallmark of genomic instability (GIN). Results: This study demonstrates differences in 53BP1 NF expression between FA and FC. The incidence of 53BP1 at NF significantly increased with FT progression in the following order: normal follicle < FA < minimally invasive FCs < widely invasive FCs. In contrast, no significant differences were observed in CNAs among the FT samples. Furthermore, there was no significant correlation between CNAs and 53BP1 at NF in FTs. Thus, based on a comparison of these two indicators of GIN, 53BP1 NF (by IF) was better able to estimate the malignancy of FTs compared to CNA (by array comparative genomic hybridization). Interestingly, IF revealed a heterogenous distribution of 53BP1 NF, which occurred more frequently in the invasive or subcapsular area than in the center of the tumor, suggesting intratumoral heterogeneity of GIN in FTs. Conclusions: It is proposed that IF analysis of 53BP1 expression could be a novel diagnostic method to estimate the malignant potential of FTs. Because 53BP1 NF reflect DNA double-strand breaks, it is hypothesized that the incidence of 53BP1 at NF can represent the level of GIN in tumor cells. IF analysis of 53BP1 expression will not only be an auxiliary histologic technique to diagnose FTs accurately, but also a novel technique for preoperative diagnosis using fine-needle aspiration cytology.

"Atrophic Kidney"-like Lesion: Clinicopathologic Series of 8 Cases Supporting a Benign Entity Distinct From Thyroid-like Follicular Carcinoma.

Renal mass lesions with a follicular architecture resembling atrophic kidney have been described, but their distinction from thyroid-like follicular carcinoma of the kidney remains controversial. We collected 8 cases of this purported "atrophic kidney"-like lesion to fully describe their clinical and histologic spectrum, their possible etiology, and to discuss their distinction from other renal neoplasms. Eight total cases were identified with patient ages ranging from 9 to 48 years (mean: 29 y; median: 28.5 y). Four patients were female and 4 were male. The tumors were unifocal and size ranged from 1.6 to 4.9 cm (mean: 3.4 cm; median: 3.4 cm). All 8 tumors had a remarkably similar histology. Each was enveloped by a smooth muscle rich capsule and had an overall low power "follicular" architecture. The luminal spaces of the "follicles" (or cysts) contained eosinophilic secretions and the lining epithelium was often flattened and atrophic, but some had more rounded cells with a distinctive hobnail arrangement. Many cysts contained discohesive round cells floating within the eosinophilic material, and some contained small intraluminal tufts with features of markedly atrophic glomeruli. Periodic acid-Schiff stains highlighted basement membrane material extending into these glomerular-like tufts, and some contained small distinct capillaries surrounded by endothelial cells, interspersed mesangial-like cells, and rare surrounding podocyte-like cells, providing additional evidence for glomerulocystic structures. Scattered calcifications were present within cysts (or within cyst walls) in varying numbers and were characterized by 2 types: psammoma body-like or more amorphous deposits. The tissue between cystic glomeruli contained predominantly small atrophic tubular structures, but collagenized stroma and smaller collapsed glomeruli were also present. The 2 tumors from the oldest 2 patients (48 and 39 y) had a more striking degree of stromal hyalinization. Immunohistochemically, the cyst lining cells had a predominant WT-positive/PAX-8 negative/CK7-negative phenotype, while tubules were typically WT-1 negative/PAX-8 positive/CK7-positive. Upon comparison to a control group of 10 kidneys containing incidental non-mass-forming glomerulocystic change, the morphologic features and immunophenotype were identical. To date, no patient has had any recurrence or aggressive clinical behavior based on follow status in 7 of 8 cases (follow-up range: 9 to 168 mo; median: 24 mo; mean: 40 mo). In summary, we describe the clinicopathologic features of 8 unique, benign "atrophic kidney"-like lesions that may simply represent a non-neoplastic form of organizing tubular atrophy and glomerulocystic change, and emphasize their distinction from thyroid-like follicular carcinoma of the kidney.

Curious Residents of the Thyroid Gland: Two Case Reports of Colorectal Carcinoma Metastasis by Fine-Needle Aspiration Diagnosis.

BACKGROUND: The most frequent metastases to the thyroid originate in the kidney, lung or breast. Colorectal adenocarcinoma represents less than 4% of metastases to the thyroid gland. Solitary metastases of colorectal cancer with no other manifestation of disseminated cancer disease are exceedingly rare. Within the Bethesda Classification for Reporting -Thyroid Cytopathology, metastases are included in Diagnostic Categories "Suspicious for Malignancy" and "Malignant." CASES: We present 2 cases of colorectal adenocarcinoma metastatic to the thyroid gland, diagnosed by fine-needle aspiration (FNA). One metastasis occurred in normal thyroid parenchyma; the other was a tumour-to-tumour metastasis into a follicular carcinoma of the thyroid. The latter is the first published tumour-to-tumour metastasis of a colorectal carcinoma in the thyroid from which both components were diagnosed by FNA. CONCLUSION: Diagnosing a metastasis to the thyroid is challenging. On FNA, a dual cell population should raise suspicion. Immunocytochemical and molecular analysis may be helpful. Clinical information is essential in guiding specific ancillary technique panels in scant cellular material.

Incidental thyroid carcinoma in patients with TIR1, TIR2 and TIR3 FNA.

AIM: The aim of our study was to evaluate the presence of incidental differentiated thyroid carcinomas, at final histological examination, in patients undergoing thyroidectomy or lobectomy for presumed benign pathology or in those with cytological diagnosis of indeterminate nodules (TIR3). MATERIAL OF STUDY: 457 patients who underwent surgery for benign disease and 179 patients with indeterminate FNA were included in our study. RESULTS: 77 out of 457 patients had the diagnosis of differentiated thyroid carcinoma. 29 out of 179 patients had the same diagnosis as previous ones, but not on the undetermined FNA nodule. In the most of the cases, the istotype was follicular variant of papillary carcinoma. DISCUSSION: The incidence of incidental carcinomas, approximately the same in the two groups of patients, respectively 16.8% and 16.2%, shows that there is still a group of patients with benign thyroid disease escaping a careful ultrasound evaluation and therefore a targeted FNA. Even in patients with indeterminate cytology, the presence of an incidental carcinoma suggests that on the one hand there has been an overestimation and on the other a non-recognition of the really suspect nodule. Although in most cases it is a microcarcinoma, we must not overlook the presence of many tumors at stage T3. CONCLUSIONS: Surely the analysis of the set of risk factors with a wider application of molecular biology surveys will in the future lead to better selection of patients to undergo surgery sooner than those that can be followed in follow up even for a longer period of time. KEY WORDS: Differentiated thyroid carcinoma, Fine needle aspiration, Incidental carcinoma.

Proof-of-concept Raman spectroscopy study aimed to differentiate thyroid follicular patterned lesions.

Inter-observer variability and cancer over-diagnosis are emerging clinical problems, especially for follicular patterned thyroid lesions. This challenge strongly calls for a new clinical tool to reliably identify neoplastic lesions and to improve the efficiency of differentiation between benign and malignant neoplasms, especially considering the increased diagnosis of small carcinomas and the growing number of thyroid nodules. In this study, we employed a Raman spectroscopy (RS) microscope to investigate frozen thyroid tissues from fourteen patients with thyroid nodules. To generate tissue classification models, a supervised statistical analysis of the Raman spectra was performed. The results obtained demonstrate an accuracy of 78% for RS based diagnosis to discriminate between normal parenchyma and follicular patterned thyroid nodules, and 89% accuracy - for very challenging follicular lesions (carcinoma versus adenoma). RS translation into intraoperative diagnosis of frozen sections and in preoperative analysis of biopsies can be very helpful to reduce unnecessary surgery in patients with indeterminate cytological reports.

[Clinicopathologic characteristics of thyroid-like follicular carcinoma of the kidney: an analysis of five cases and review of literature].

Objective: To study the clinicopathologic features of thyroid-like follicular renal cell carcinoma. Methods: Clinical data were collected in 5 cases of thyroid-like follicular renal cell carcinoma. HE staining and immunohistochemistry were carried out in surgically-removed specimen to analyze the clinical and pathological features with review of the literatures. Results: The patients aged 20-55 years, with one male and four females; the tumor occurred in the left kidney in three cases and right kidney in two cases. One case had a history of thyroid papillary carcinoma 3 years ago, and the patient had left flank pain, macroscopic haematuria for 2 weeks. The rest four cases had no consciousness of clinical symptoms and signs, without history of thyroid gland surgery; the physical examination found a mass in the kidney and normal thyroid glands. Three patients underwent radical nephrectomy, and the other two patients underwent tumor partial nephrectomy. The tumors were 2-4 cm in size. They showed a solitary nodular mass of well circumscribed with taupe and gray on cut surface. Microscopically, most of tumor cells arranged in thyroid follicular pattern in different sizes, with papillary configuration in a small portion, in four cases; the follicular structure was intermixed with the papillary each half in one case. A large amount of thyroid colloid was deposited within follicule-like structure or papillary axis, lined by simple columnar cells or cubic cells, with obvious atypia, ground-glass nuclei, nuclear groove and rare mitosis. Immunohistochemical staining showed tumor cells were positive for PAX8, and negative for thyroid transcription factor 1 (TTF1) and thyroglobulin (Tg). One of five patients presented with lymph node metastases (4/4) of renal hilum the same time in the diagnosis. Five cases were followed up for 5-84 months after operation, and no tumor progression was found. Conclusions: Thyroid-like follicular renal cell carcinoma is primary renal epithelial malignant tumor. The diagnosis mainly depends on its characteristics of histological appearance, namely similar to the histological morphology of well-differentiated thyroid follicular carcinoma and papillary carcinoma, and the metastasis from the thyroid papillary or follicular carcinoma must be excluded. On the premise of clinical history, immunohistochemical markers TTF1 and Tg have certain value in the differential diagnosis.

E-cadherin/α-catenin deregulated co-expression in thyroid carcinoma based on tissue microarray digital image analysis.

PURPOSE: Deregulation of cell-to-cell adhesion molecules is a common and also critical genetic event in epithelial malignancies leading to an increasing metastatic potential. Among them, e-cadherin and catenins--especially α and ß--, act as oncogenes during the carcinogenetic process affecting specific signaling transduction pathways (i.e. Wnt/ b-catenin). Concerning thyroid carcinoma, decreased or loss of expression in these proteins seems to affect the biological behavior of the neoplasm increasing its aggressiveness. The aim of this study was to investigate the deregulation of e-cadherin/α-catenin complex in thyroid carcinomas. METHODS: Thirty-five paraffin-embedded tissue samples including thyroid carcinomas (N=20) and also 15 cases of benign follicular nodules were cored at 1 mm diameter and transferred to a microarray block. Immunohistochemistry (IHC) was performed using anti-e-cadherin/α-catenin antibodies. Digital image analysis was also implemented for measuring the corresponding protein expression levels. RESULTS: E-cadherin/α-catenin protein expression demonstrated a significant progressive decrease regarding benign and malignant lesions (p=0.001). Simultaneous e-cadherin/α-catenin reduced or loss of expression was observed in 10/20 (50%) cancer cases correlated to advanced stage (especially nodal metastasis) of the examined tumours (p=0.02). Concerning the histological type, combined loss of e-cadherin/α-catenin expression was predominantly associated with follicular and anaplastic histology (p=0.001). Interestingly, α-catenin protein expression pattern was significantly correlated with the grade of differentiation of the examined malignancies (p=0.01). CONCLUSIONS: Progressive loss of e-cadherin mainly and also α-catenin expression is associated with an aggressive phenotype (low differentiation, increased metastatic activity/advanced stage) in thyroid carcinomas. Based on their aberrant protein expression, novel agents have been developed for restoring their normal function.

Cytological features of "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" and their correlation with tumor histology.

Among thyroid papillary carcinomas (PTCs), the follicular variant is the most common and includes encapsulated forms (EFVPTCs). Noninvasive EFVPTCs have very low risk of recurrence or other adverse events and have been recently proposed to be designated as noninvasive follicular thyroid neoplasm with papillary-like nuclear features or NIFTP, thus eliminating the term carcinoma. This proposal is expected to significantly impact the risk of malignancy associated with the currently used diagnostic categories of thyroid cytology. In this study, we analyzed the fine needle aspiration biopsy (FNAB) cytology features of 96 histologically proven NIFTPs and determined how the main nuclear features of NIFTP correlate between cytological and histological samples. Blind review of FNAB cytology from NIFTP nodules yielded the diagnosis of "follicular neoplasm" (Bethesda category IV) in 56% of cases, "suspicious for malignancy" (category V) in 27%, "atypia of undetermined significance/follicular lesion of undetermined significance" (category III) in 15%, and "malignant" (category VI) in 2%. We found good correlation (κ=0.62) of nuclear features between histological and cytological specimens. NIFTP nuclear features (size, irregularities of contours, and chromatin clearing) were significantly different from those of benign nodules but not from those of invasive EFVPTC. Our data indicate that most of the NIFTP nodules yield an indeterminate cytological diagnosis in FNAB cytology and nuclear features found in cytology samples are reproducibly identified in corresponding histology samples. Because of the overlapping nuclear features with invasive EFVPTC, NIFTP cannot be reliably diagnosed preoperatively but should be listed in differential diagnosis of all indeterminate categories of thyroid cytology.

Immunohistochemical detection of NRAS(Q61R) protein in follicular-patterned thyroid tumors.

The NRAS(A182G) mutation, which results in the NRAS(Q61R) protein, is a major driver mutation in follicular-patterned thyroid neoplasms. Although new immunohistochemistry (IHC) for NRAS(Q61R) is now available, its sensitivity, specificity, and diagnostic utility for thyroid tumors are not yet established. We performed IHC for NRAS(Q61R) and direct sequencing for NRAS codon 61 in 4 thyroid cancer-derived cell lines and 98 follicular-patterned thyroid tumors that included 22 follicular thyroid adenomas (FTAs), 35 follicular thyroid carcinomas (FTCs), and 41 cases of nodular hyperplasia (NH). In the tumors with NRAS(Q61R), the expression of BRAF(V600E) was further evaluated immunohistochemically. Two cell lines with NRAS(A182G) showed selective immunoreactivity for NRAS(Q61R). In tumor tissues, NRAS(Q61R) IHC was positive in 18% (4/22), 29% (10/35), and 2% (1/41) of FTAs, FTCs, and NH samples, respectively. The frequencies of the NRAS(Q61R) in FTAs and FTCs were significantly higher than that in NH (P=.046 and P=.001, respectively). All tumors with NRAS(Q61R) expression exhibited uniform cytoplasmic positivity with or without accumulation in their cell membranes. Of the 15 tumors with NRAS(Q61R) expression, 13 cases showed NRAS(A182G) in direct sequencing, whereas all of the tumors without NRAS(Q61R) expression were negative for the mutation. There were no tumors with overlapping expression of NRAS(Q61R) and BRAF(V600E). In reference to the direct sequencing, sensitivity and specificity of the NRAS(Q61R) IHC were 100% and 98%, respectively. In conclusion, NRAS(Q61R) IHC is a highly sensitive and specific tool that is useful for differentiating follicular-patterned thyroid tumors.

Role of GPER1, EGFR and CXCR1 in differentiating between malignant follicular thyroid carcinoma and benign follicular thyroid adenoma.

It is extremely difficult to discriminate between follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FTA) before surgery, because the morphologies of carcinoma cells and adenoma cells obtained by fine needle aspiration biopsy (FNAB) are similar. Molecular markers may be helpful on this issue. The purpose of this study was to assess the role of GPER1, EGFR and CXCR1 in differential diagnosis between FTC and FTA. GPER1, EGFR and CXCR1 mRNA expression levels were examined in 15 FTCs and 10 FTAs using real-time RT-PCR. FTC showed to have significantly increased mRNA levels of the three molecules compared to FTA (P < 0.001 for all the three molecules). GPER1, EGFR and CXCR1 protein expression in 106 FTCs and 128 FTAs were analyzed using immunohistochemistry. The rates of GPER1, EGFR and CXCR1 high expression were 73.6%, 72.6% and 70.8% in FTC and 30.5%, 28.1% and 27.3% in FTA, respectively. Statistical analysis showed that GPER1, EGFR and CXCR1 protein expression were correlated with one another in FTC and concomitant high expression of the three molecules had stronger correlation with the occurrence of FTC than did each alone. The positive predictive values (PPV) for concomitant high expression of the three molecules for discriminating between FTC and FTA were 91.0% for GPER1/EGFR, 93.8% for GPER1/CXCR1, 92.3% for EGFR/CXCR1 and 98.2% for GPER1/EGFR/CXCR1, respectively. These results indicated that the evaluation of GPER1, EGFR and CXCR1 concomitant high expression may be helpful in differential diagnosis between FTC and FTA.

Cyclin D1 in well differentiated thyroid tumour of uncertain malignant potential.

BACKGROUND: Encapsulated follicular tumours with equivocal papillary thyroid carcinoma (PTC) type nuclear features continue to remain a challenge despite the recent attempts to classify these borderline lesions. The term 'well differentiated tumour of uncertain malignant potential (WDT-UMP)' was introduced to classify these tumours. The present study aimed to evaluate the role of a cell cycle regulator like cyclin D1 in these tumours along with assessment of other well established PTC markers like galectin-3, HBME-1, CK19. METHODS: Thirteen cases of metastatic PTC, papillary microcarcinoma and follicular variant of PTC (FVPTC) were identified from a histological review of 510 cases. In addition, 13 cases of a subset of follicular adenomatoid nodules with focal areas showing nuclear features characteristic of PTC, identified as WDT-UMP, were also analyzed. Immunohistochemical analysis of galectin-3, HBME-1, CK19 and the proliferation markers Ki67 and cyclin D1 was performed. Lesions were analyzed for cyclin D1 gene amplification by fluorescent in-situ hybridization. RESULTS: All WDT-UMP lesions showed immunolabelling of cyclin D1, Ki67; 11/ 13 cases showed immunolabelling of CK19; 10/13 cases showed immunolabelling of HBME-1 and 4/13 cases showed immunolabelling of galectin-3. Surrounding benign adenomatoid areas showed no to faint focal staining in all thirteen cases of cyclin D1, HBME-1 and galectin-3. A low rate of cyclin D1 gene amplification was identified in a significant proportion of cells in the WDT-UMP lesions as compared to surrounding benign adenomatoid areas. CONCLUSIONS: Increased expression of cyclin D1 and amplification of its gene along with immunolabelling of HBME-1 in WDT-UMP lesions showing cytological features of papillary thyroid carcinoma within follicular adenomatoid nodules suggest that these areas could correspond to a precursor lesion of follicular variant of PTC. Overexpression of cyclin D1, associated with the amplification of the gene suggests that these WDT-UMP lesions are an intermediate between the benign and malignant groups making this group of lesions a reliable precursor of FVPTC. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1851820807142117.

Skull metastasis from follicular thyroid carcinoma: report of three cases and review of literature.

Three patients' medical history, clinical manifestation, imaging characteristic, therapy and prognosis of calvaria metastasis from follicular thyroid carcinoma (FTC) in our hospital were retrospectively analyzed by reviewing medical literature. In case one, the tumor in frontal bone and fossa orbital was total resected, no further treatment was performed, the patient gave up on therapy and died of extensive metastasis at 22 months after the initial operation. In case two, the tumor in parietal and occipital bone was total resected, the subtotal resection of bilateral thyroid gland and isthmus was performed and combined with therapy of Levothyroxine and (131)I radio-iodine therapy, no evidence of tumor recurrence at 30 months after the primary operation. In case three, the tumor in occipital bone was gross total resected, total resection of bilateral thyroid gland and clearance of lymph node was performed after two months, adjunctive therapy with Levothyroxine, (131)I radio-iodine and skull radiotherapy, no evidence of tumor recurrence at 21 months after the primary operation. Correct diagnosis of calvaria metastasis from FTC preoperative is difficult because it's rarity, patients can survive for years after synthetic therapy including total resection of metastatic tumor, radical operation of thyroid carcinoma, adjunctive therapy of Levothyroxine, (131)I radio-iodine and skull radiotherapy.

Clinical, pathologic, and immunohistochemical prognostic factors in dogs with thyroid carcinoma.

BACKGROUND: Prognostic markers for dogs with thyroid tumors are limited. HYPOTHESIS/OBJECTIVES: To identify clinical, pathologic, and immunohistochemical prognostic factors for dogs with thyroid tumors. ANIMALS: Seventy dogs with thyroid neoplasia. METHODS: Retrospective study. Dogs with thyroid neoplasia were included when follow-up information and formalin-fixed paraffin-embedded tumor samples were available. Immunohistochemistry (IHC) was performed for thyroglobulin, calcitonin, Ki-67, and E-cadherin. Correlation of tumor variables (diameter, volume, localization, scintigraphic uptake, thyroid function, IHC) with local invasiveness and metastatic disease was performed on all tumor samples. Forty-four dogs treated by thyroidectomy were included in a survival analysis. RESULTS: Fifty dogs (71%) had differentiated follicular cell thyroid carcinoma (dFTC) and 20 (29%) had medullary thyroid carcinoma (MTC). At diagnosis, tumor diameter (P = .007; P = .038), tumor volume (P = .020), tumor fixation (P = .002), ectopic location (P = .002), follicular cell origin (P = .044), and Ki-67 (P = .038) were positively associated with local invasiveness; tumor diameter (P = .002), tumor volume (P = .023), and bilateral location (P = .012) were positively associated with presence of distant metastases. Forty-four dogs (28 dFTC, 16 MTC; stage I-III) underwent thyroidectomy. Outcome was comparable between dogs with dFTC and MTC. Macroscopic (P = .007) and histologic (P = .046) vascular invasion were independent negative predictors for disease-free survival. Although time to presentation, histologic vascular invasion and Ki-67 were negatively associated with time to metastases, and time to presentation was negatively associated with time to recurrence, no independent predictors were found. E-cadherin expression was not associated with outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Prognostic factors have been identified that provide relevant information for owners and clinicians.

The nightmare of indeterminate follicular proliferations: when liquid-based cytology and ancillary techniques are not a moon landing but a realistic plan.

OBJECTIVE: Thyroid nodules are a common finding in the general population, including both nonneoplastic and neoplastic entities. Fine-needle aspiration cytology (FNAC) is the first tool for evaluating thyroid nodules. In spite of its high diagnostic accuracy, 25% of nodules result in the category of follicular neoplasms (FN), with varying risk of malignancy and different management strategies. STUDY DESIGN: The use of ancillary techniques is reshaping the practice of FNAC. These tools can significantly empower the morphological diagnosis and prognosis of thyroid nodules, allowing a more accurate prediction of the nature of the lesion. Several studies have underlined the role of single or multiple testing for the category of FN as strong indicators of cancer. Every cytological preparation can be used for the application of ancillary techniques but the introduction of liquid-based cytology (LBC) might facilitate the application. RESULTS: Our experience involving an immunocytochemical panel made up of HBME-1 and galectin-3 pointed to an 81% overall diagnostic accuracy in discriminating between low and high risk of malignancy in FN. CONCLUSIONS: The application of these techniques on LBC represents an adjunct to the morphological evaluation of FN. They represent a critical and challenging, but also a feasible, tool in the preoperative diagnoses, allowing specific prognostic and predictive details regardless of the cytological preparation. © 2014 S. Karger AG, Basel.

Identification of RASAL1 as a major tumor suppressor gene in thyroid cancer.

BACKGROUND: RAS-coupled MAPK and PI3K pathways play a fundamental role in thyroid tumorigenesis, and classical genetic alterations upregulating these pathways are well characterized. We hypothesized that gene abnormality of negative modulators of these signaling pathways might be an important alternative genetic background for thyroid cancer. METHODS: By examining gene expression patterns of negative modulators of RAS signaling, we attempted to identify potential tumor suppressor genes. We then analyzed the methylation and mutation patterns of the identified gene in 101 thyroid tumors and tested its functions in vitro and in vivo to establish the tumor suppressor role in thyroid cancer. RESULTS: Among 13 negative modulators of the RAS pathway screened, RASAL1, encoding a RAS GTPase-activating protein, was frequently hypermethylated in thyroid cancers, which was coupled to its silencing in thyroid cancer cells. We also, for the first time, identified the presence of RASAL1 mutations, with a prevalence of 4.88% (n = 2 of 41) in follicular thyroid cancer (FTC) and 16.67% (n = 5 of 30) in anaplastic thyroid cancer (ATC). RASAL1 displayed MAPK- and PI3K-suppressing and thyroid tumor-suppressing activities, which were all impaired by the mutations. Hypermethylation and mutations of RASAL1 were mutually exclusive and collectively found in zero of 20 benign thyroid tumors, 3.22% (n = 1 of 31) of papillary thyroid cancers, 31.70% (n = 13 of 41) of FTCs, and 33.33% (n = 10 of 30) of ATCs. A rate of 20.83% (n = 5 of 24) of tumors carrying RASAL1 mutation or methylation at high levels (>50%) vs 44.16% (n = 34 of 77) of tumors carrying no RASAL1 mutation or methylation at low levels (< 50%) harbored any of the classical mutations (two-sided P = .02, Fisher exact test) in RAS, BRAF, PTEN, and PIK3CA genes in the MAPK and PI3K pathways, revealing a largely mutually exclusive relationship. CONCLUSIONS: We identified RASAL1 as a major tumor suppressor gene that is frequently inactivated by hypermethylation and mutations, providing a new alternative genetic background for thyroid cancer, particularly FTC and ATC.

[Diagnostic value of BRAFV600E and RET/PTC oncogenes in thyroid nodule aspirates]. / Valore diagnostico degli oncogeni BRAFV600E e RET/PTC nei noduli tiroidei.

Fine-needle aspiration cytology (FNC) is the primary means to distinguish benign form malignant nodules. Aim of this study is to evaluate the diagnostic value of BRAF(V600E) and RET/PTC oncogenes in a large cohort of thyroid nodules with inconclusive FNC. We searched for BRAF(V600E) and RET/PTC in 299 thyroid nodule aspirates then removed by surgery. RET/PTC demonstrated a poor specificity. The search for BRAF(V600E) demonstrated to be useful in 25 cases, identifying a PTC in 2 false negative, 2 inadequate, 11 indeterminate and 10 suspicious FNC. Detection of BRAF(V600E) revealed to be a useful tool to refine inconclusive cytology.