Papillary Thyroid Carcinoma: An Overview

Whispers in the Neck: Unmasking Cystic Metastases From Hidden Papillary Thyroid Carcinoma

Papillary thyroid carcinoma is the most common thyroid malignancy and it frequently causes lymph node metastases. Approximately 50% of patients with papillary thyroid carcinoma have cervical lymph node metastases at the time of their initial presentation. Here we report a case of a young female who presented with a benign-appearing cystic neck mass, which was revealed to be metastases from occult papillary thyroid carcinoma. Completion thyroidectomy and neck dissection were done after the diagnosis of papillary thyroid carcinoma.

Quantitative parameters of contrast-enhanced ultrasound effectively promote the prediction of cervical lymph node metastasis in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC), the most common endocrine tumor, often spreads to cervical lymph nodes metastasis (CLNM). Preoperative diagnosis of CLNM is important when selecting surgical strategies. Therefore, we aimed to explore the effectiveness of quantitative parameters of contrast-enhanced ultrasound (CEUS) in predicting CLNM in PTC. We retrospectively analyzed 193 patients with PTC undergoing conventional ultrasound (CUS) and CEUS. The CUS features and quantitative parameters of CEUS were evaluated according to PTC size ≤ 10 or > 10 mm, using pathology as the gold standard. For the PTC ≤ 10 mm, microcalcification and multifocality were significantly different between the CLNM (+) and CLNM (-) groups (both P < 0.05). For the PTC > 10 mm, statistical significance was noted between the two groups with respect to the margin, capsule contact, and multifocality (all P < 0.05). For PTC ≤ 10 mm, there was no significant difference between the CLNM (+) and CLNM (-) groups in all quantitative parameters of CEUS (all P > 0.05). However, for PTC > 10 mm, the peak intensity (PI), mean transit time, and slope were significantly associated with CLNM (all P < 0.05). Multivariate analysis showed that PI > 5.8 dB was an independent risk factor for predicting CLNM in patients with PTC > 10 mm (P < 0.05). The area under the curve of PI combined with CUS (0.831) was significantly higher than that of CUS (0.707) or PI (0.703) alone in the receiver operator characteristic curve analysis (P < 0.05). In conclusion, PI has significance in predicting CLNM for PTC > 10 mm; however, it is not helpful for PTC ≤ 10 mm.

Challenging Case of Anaplastic Thyroid Cancer With Unusual Clinical and Histological Features: A Diagnostic Dilemma With Undifferentiated Pleomorphic Sarcoma

Thyroid cancer is a common malignancy worldwide, and its incidence is increasing rapidly, especially in women. In the majority of cases, it presents solely with a palpable neck swelling. Less commonly, the disease manifests with symptoms of advanced stages, such as superior vena cava (SVC) obstruction and indications of recurrent laryngeal nerve invasion. Anaplastic thyroid cancer is a rare variant of thyroid cancer and is considered to have one of the poorest prognoses, and its diagnosis and treatment are challenging. On the other hand, undifferentiated pleomorphic sarcoma is a differential diagnosis with many clinical and histological similarities, which can only be confirmed through immunohistochemical studies. We herein report a challenging case of a 69-year-old female patient who presented with obstructive symptoms, diagnosed with anaplastic thyroid cancer exhibiting unusual clinical and histological features.

Orthodenticle Homeobox OTX1 Promotes Papillary Thyroid Carcinoma Progression and Is a Potential Prognostic Biomarker

Papillary thyroid carcinoma (PTC) is the most common type of thyroid neoplasms, characterized by evidence of follicular cell differentiation. Orthodenticle homeobox 1 (OTX1) is a transcription factor which has been implicated in numerous diseases, including malignancies. The objective of this research was to explore the function of OTX1 in PTC. Immunohistochemistry (IHC) was employed to determine the protein level of OTX1 in PTC specimens. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, a xenograft model on nude mice was established to investigate in vivo effects of OTX1. Our results revealed that OTX1 was significantly upregulated within specific PTC tissues and was remarkably correlated with unfavorable clinical outcomes in PTC. Silencing OTX1 resulted in a significant inhibition in cell viability and suppressed cell proliferation. In addition, in vivo experiments demonstrated that OTX1 silencing resulted in a significant suppression of tumor growth in nude mice. Collectively, these results suggest that OTX1 may play crucial roles in promoting PTC progression.

ENST00000438158 aids ultrasound for predicting lymph node metastasis and inhibits migration and invasion of papillary thyroid carcinoma cells

Cervical lymph node metastasis (CLNM) of papillary thyroid carcinoma (PTC) is directly associated with clinical management and prognosis. In this study, we aimed to evaluate the value of conventional ultrasound (US) combined with ENST00000438158 in predicting CLNM of PTC. Fourty-nine PTC patients underwent US examination and US-guided fine needle aspiration (FNA). ENST00000438158 expression in FNA cytological specimens and PTC cell lines was detected using real-time reverse transcription polymerase chain reaction (qRT-PCR). The role of ENST00000438158 expression in the proliferation, migration, invasion, apoptosis, and cell cycle of PTC cells was investigated by Cell Counting Kit-8 (CCK8) and clone formation experiments, transwell assay, and flow cytometry, respectively. Calcification, capsule contact, and low ENST00000438158 expression were independently associated with PTC with CLNM (all p < 0.05). The combination of multiple US features was more valuable than a single US feature in predicting CLNM in PTC. Adding ENST0000438158 to US greatly improved the value of differentiation of PTC with or without CLNM. In conclusion, ENST00000438158 is a potential molecular marker for predicting CLNM in PTC. ENST00000438158 combined with US features is highly valuable for predicting CLNM in PTC.

Establishment of papillary thyroid cancer organoid lines from clinical specimens

Papillary thyroid cancer (PTC) is a common malignancy of the endocrine system, and its morbidity and mortality are increasing year by year. Traditional two-dimensional culture of cell lines lacks tissue structure and is difficult to reflect the heterogeneity of tumors. The construction of mouse models is inefficient and time-consuming, which is difficult to be applied to individualized treatment on a large scale. Clinically relevant models that recapitulate the biology of their corresponding parental tumors are urgently needed. Based on clinical specimens of PTC, we have successfully established patient-derived organoids by exploring and optimizing the organoid culture system. These organoids have been cultured stably for more than 5 passages and successfully cryopreserved and retried. Histopathological and genome analysis revealed a high consistency of the histological architectures as well as mutational landscapes between the matched tumors and organoids. Here, we present a fully detailed method to derive PTC organoids from clinical specimens. Using this approach, we have developed PTC organoid lines from thyroid cancer samples with a success rate of 77.6% (38/49) until now.

Fibrinogen-to-Neutrophil Ratio as a New Predictor of Central Lymph Node Metastasis in Patients with Papillary Thyroid Cancer and Type 2 Diabetes Mellitus

Background

Many patients have a higher risk of thyroid cancer if they have both papillary thyroid carcinoma (PTC) and Type 2 diabetes mellitus (T2DM). Meanwhile, the primary reason for local PTC recurrence is cervical lymph node metastasis. Therefore, the prognosis of patients affects how cervical lymph nodes are managed during surgery. Due to surgical complications such as laryngeal nerve palsy and hypocalcemia, it is still debatable whether to prevent central lymph node dissection (CLND). Predicting central lymph node metastasis (CLNM) is crucial to direct CLND. It is unclear how important the fibrinogen-to-neutrophil ratio (FNR) is in thyroid cancer, so we looked into how it might help patients with PTC and T2DM predict CLNM.

Patients and methods

Wenzhou Medical University's First Affiliated Hospital provided us with 413 patients with PTC and T2DM, randomly divided into a training set (N = 292) and a validation set (N = 121). Univariate and multivariate logistic regression analyses were used to identify independent risk factors. After constructing a nomogram, the validity of the model was evaluated.

Results

The maximum tumor diameter, high-density lipoprotein, thyroxine, triglyceride, lymphocyte, and FNR were all identified as independent risk factors by multivariate logistic regression analysis. The C index of the training set was 0.775, and the validation set was 0.654.

Conclusion

In patients with PTC and T2DM, preoperative FNR was an independent risk factor for CLNM.

Posttranslational Modifications in Thyroid Cancer: Implications for Pathogenesis, Diagnosis, Classification, and Treatment

There is evidence that posttranslational modifications, including phosphorylation, acetylation, methylation, ubiquitination, sumoylation, glycosylation, and succinylation, may be involved in thyroid cancer. We review recent reports supporting a role of posttranslational modifications in the tumorigenesis of thyroid cancer, sensitivity to radioiodine and other types of treatment, the identification of molecular treatment targets, and the development of molecular markers that may become useful as diagnostic tools. An increased understanding of posttranslational modifications may be an important supplement to the determination of alterations in gene expression that has gained increasing prominence in recent years.

Proto-oncogene Pokemon in thyroid cancer: a potential promoter of tumorigenesis in papillary thyroid carcinoma

Background

Pokemon is an oncogenic transcription regulator that plays a critical role in cellular differentiation. Although it has been found to be overexpressed in several types of cancer involving different organs, its role in thyroid gland has yet to be reported. The objective of this study was to evaluate the expression of Pokemon in papillary thyroid carcinoma (PTC) based on clinicopathological parameters.

Methods

Tissue microarray samples derived from patients with PTC or benign thyroid disease were used to evaluate Pokemon expression based on immunohistochemical analysis. Correlations of its expression with various clinicopathological parameters were then analyzed.

Results

Pokemon expression was observed in 22.0% of thyroid follicular cells from the normal group, 44.0% from the group with benign thyroid diseases, and 92.1% from the group with PTC (p < .001). The intensity of Pokemon expression was markedly higher in the PTC group. Pokemon expression level and PTC tumor size showed an inverse correlation. T1a tumors showed strong expression levels of Pokemon. However, larger tumors showed weak expression (p = .006).

Conclusions

Pokemon expression is associated with tumorigenesis of PTC, with expression showing an inverse correlation with PTC tumor size. This might be related to the negative regulation of aerobic glycolysis by Pokemon.

Correlation of the Expression of BRAF V600E Mutation With Various Phenotypic Expressions of Thyroid Neoplasms

Aims We aimed to assess the incidence of the BRAF V600E mutation in thyroid neoplasms at a tertiary care center and its association with various phenotypic features. Methods and material We included all cases diagnosed as thyroid neoplasm in the past decade at the Department of Pathology of our institute and obtained their clinical details from the medical records department of the institute after obtaining permission from the authorities and due International Human Epigenome Consortium clearance. We included data on age, sex, clinical presentation, hormone status, and T and N status of the malignant neoplasms. Hematoxylin and eosin (H&E) slides of all cases were evaluated for the type of neoplasm, nuclear features, invasion into the capsule and vascular spaces, extrathyroidal extension, lymph node metastases, mitoses, necrosis, and presence/absence of amyloid. Paraffin blocks of sections with high tumor density and less normal tissue were chosen for evaluation after H&E staining. The slides showing tumors with large areas of hemorrhage, cystic change, or necrosis were excluded. Two primers were used to amplify a 339-bp fragment containing the V600E mutation in exon 15 of BRAF. Tissues were prepared from formalin-fixed paraffin-embedded (FFPE) blocks, and DNA was isolated using a standard protocol BRAF NF and BRAF NR Primer Standardized Protocol For FFPE Tissue DNA. Percentages and tables have been used for data presentation. Results Among 47 identified cases, 14 were positive for the BRAF V600E mutation and had papillary carcinoma (n = 9) or follicular neoplasms (n = 5; follicular adenoma, n = 3; follicular carcinoma, n = 2). In the BRAF-positive papillary carcinomas, five cases were aged 20-30 years, eight were female, eight (88.88%) were euthyroid, and one was hypothyroid. Furthermore, 55.55% (5/9 cases) of BRAF-positive cases were stage I, 33.3% (3/9 cases) were stage II, and 0.02% (1/9 cases) were stage III. Conclusions In our cohort, 31% of cases of papillary thyroid carcinoma (PTC) and 18.72% of follicular neoplasms expressed the BRAF V600E mutation. BRAF V600E mutation-positive papillary thyroid carcinomas consistently showed all characteristic nuclear features, such as nuclear crowding, overlapping, and grooves. Considering the greater prevalence in the younger age group, the importance of mutation surveillance in PTCs for a total thyroidectomy may be warranted in mutation-positive patients.

Is a simplified TNM staging system more clinically relevant than the American Joint Committee on Cancer system for the follicular variant of papillary thyroid cancer?

Background

Despite the recent release of the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual, risk stratification for the follicular variant of papillary thyroid cancer (FVPTC), which is the second common variant of papillary thyroid carcinoma (PTC) after classical PTC, remains controversial. This study aimed to develop a more accurate and relevant staging system specifically for FVPTC.

Methods

Patients with FVPTC who were included in the Surveillance, Epidemiology, and End Results (SEER) open database between 2010 and 2015 were divided into 47 groups according to their TNM classifications and age. Subsequently, these 47 groups were categorized into appropriate stages based on Kaplan-Meier survival curves, mortality analyses, a Cox proportional hazards model, and clinical considerations.

Results

Our retrospective analysis of 17,628 cases yielded the following new staging classification: stage I, defined as age <55 years and any T/N/M or age ≥55 years and T1-3/any N/M0 (n=17,427, 98.85%); stage II, age ≥55 and T4/any N/M0 or age ≥55 and any T/N0/M1 (n=173, 0.99%); and stage III, age ≥55 and any T/N1/M1 (n=28, 0.16%). The overall mortality rates per 1,000-person-years were 4.135 [95% confidence interval (CI): 3.653–4.681], 71.193 (95% CI: 51.354–98.697), and 199.744 (95% CI: 115.983–343.997) for our new stages I, II, and III, respectively. The hazard ratios for the new stages II and III (reference: stage I) were 5.081 (95% CI: 3.110–8.301) and 21.690 (95% CI: 11.402–41.258), respectively.

Conclusions

Compared to the 8th edition of the AJCC staging system, our newly proposed system provided more accurate risk stratification for patients with FVPTC, as demonstrated by actual survival and mortality outcomes. This new model may thus help guide more personalized treatment for these patients.

Papillary carcinoma thyroid with anastomosing channels: An unusual morphology

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, accounting for 70%–80% of all thyroid malignancies. It is biologically indolent and has an excellent prognosis. Variations in histopathologic patterns are known to influence prognosis and often result in a diagnostic dilemma. We report an unusual case of a 35-year-old female with papillary carcinoma of a thyroid isthmus showing anastomosing channels on histopathology, a distinctive pattern that has not been described in PTC. Similar to tumor cells, the lining cells of these channels were also positive for thyroid transcription factor 1, thyroglobulin, and cytokeratin-19 and negative for CD34 and CD31. The diagnosis of PTC should rely on nuclear morphology rather than architecture. Pathologists should be aware of different variants because some of these variants show aggressive behavior and poor outcome. The present report highlights the distinctive pattern of PTC, recognition of which is important to avoid any diagnostic pitfall.

Analysis of Malignant Thyroid Neoplasms with a Striking Rise of Papillary Microcarcinoma in an Endemic Goiter Region

According to National Cancer Registry Program, Thiruvananthapuram district of Kerala, has the highest relative frequency of thyroid carcinomas; nevertheless, limited data exist regarding its socio-demographic and clinico-pathological characteristics. The aims of the study were to assess the: (1) demographic characteristics, (2) histopathological features and the relative frequency of various thyroid carcinoma cases and papillary thyroid carcinoma (PTC) subtypes, (3) rising trend of papillary microcarcinomas, and (4) associated lesions. A retrospective study wherein 170 cases of thyroid malignancies reported in our single institution over a period of 8 years period was reviewed. PTC accounted for 97% cases, followed by medullary (n = 4; 2.4%) and follicular carcinoma (n = 1; 0.6%). There was female preponderance (p = 0.0379) with a lower median age in females (p = 0.0275). Among the PTCs, conventional type constituted 53.4% cases (n = 87), followed by microcarcinomas (n = 34; 20.9%), follicular variant (n = 28; 17.2%), and others 14 cases (8.5%). Thirty-three cases (19.4%) showed multifocality, 5 cases (2.9%) extra-thyroid extension, and 19 cases (11.2%) lymph node metastasis. Two cases developed recurrences and three cases, metastasis. The associated lesions were significantly higher in females (p = 0.0059); most common being multinodular goiter (MNG; n = 67; 41.1%), followed by Hashimoto thyroiditis (n = 44; 27%) and lymphocytic thyroiditis (n = 28; 17.2%); MNG being associated with follicular (p = 0.0129), and Hashimoto thyroiditis with conventional variant (p = 0.0475). The frequency of microcarcinomas significantly increased in the past 4 years (p = 0.0291) and was associated with MNG (p = 0.0055), Hurthle cell nodule (p = 0.0315) and absent lymph node metastasis (p = 0.0147). The primary treatment modality was total thyroidectomy. Papillary microcarcinoma cases increased significantly in the past 4 years and were significantly associated with MNG and Hurthle cell nodule. It is challenging to distinguish the various PTC subtypes as recognition of these histological variants warrants better patient management.

Upregulation of sphingosine kinase 1 is associated with recurrence and poor prognosis in papillary thyroid carcinoma

Sphingosine kinase 1 (SPHK1), an ATP-dependent protein, has previously been demonstrated to be upregulated in several types of human cancer and to play an important role in tumor development and progression. However, the role of SPHK1 in predicting long-term prognosis in patients with papillary thyroid carcinoma (PTC) remains unclear. The purpose of the present study was to assess the significance of SPHK1 expression and its associations with clinicopathological characteristics and prognostic outcome in patients with PTC. Immunohistochemistry staining was retrospectively performed to investigate the expression levels of SPHK1 in 92 PTC tumors. Statistical analyses revealed that high levels of SPHK1 expression were associated with tumor size, lymph node metastasis and the Tumor-Node-Metastasis stage. The disease-free survival (DFS) time of patients that exhibited high levels of SPHK1 expression was shorter, whereas patients with lower levels of SPHK1 expression survived longer. Furthermore, multivariate analysis suggested that upregulated SPHK1 was an independent prognostic factor for predicting DFS of patients with PTC. The results of the Cell Counting Kit-8 and invasion assays demonstrated that SPHK1 overexpression significantly enhanced the proliferation and invasion of a PTC cell line, consistent with clinical findings. The results from the present study provide evidence that elevated expression levels of SPHK1 may be involved in the development and progression of PTC, indicating that this protein may act as a potential prognostic marker for patients with this disease.

NADPH oxidase NOX4 is a glycolytic regulator through mROS-HIF1α axis in thyroid carcinomas

The function of the NAD(P)H oxidases (NOXs) family member NOX4 is to generate reactive oxygen species (ROS), however, the molecular function of NOX4 has not been fully studied and waiting to be clarified. To elucidate the function of endogenous Nox4 in human thyroid carcinomas, papillomatosis thyroid cancer cells were used to study the cell growth by knocking down the expression of NOX4 and knocking out its functional partner p22phox/CYBA. As a result, the increasement of mitochondrial ROS(mROS) was abolished due to both knockdown of NOX4 and p22phox knockout in hypoxia, which destabilized HIF1α decreasing glycolysis and retarded cell growth. These data suggests that Nox4 is potent oncotarget due to its role in regulating glycolysis through mROS-HIF1α pathway, thereby mediating proliferation in thyroid carcinomas.

MicroRNA-9-5p functions as a tumor suppressor in papillary thyroid cancer via targeting BRAF

MicroRNAs (miRNAs/miRs) are widely studied as key regulators of gene expression and are involved in various diseases by affecting the miRNA-mediated regulatory function. BRAF is an important oncogene in the regulation of cell proliferation and apoptosis. In the present study, reverse transcription-quantitative polymerase chain reaction was used to determine the expression levels of miR-9-5p and BRAF mRNA in patients with papillary thyroid cancer (PTC). Western blotting was used to detect BRAF protein level. A luciferase assay was used to verify the miR-9-5p target site in BRAF. Cell Counting Kit-8 and flow cytometry were used to assess cell proliferation, and apoptosis, respectively. In the present study, it was demonstrated that miR-9-5p is downregulated in malignant PTC. Using bioinformatics analysis, miR-9-5p was predicted to target the human BRAF 3'-untranslated region (3'-UTR). A dual-luciferase assay demonstrated that miR-9-5p downregulated BRAF expression by directly targeting its 3'-UTR. Mutations in the 3'-UTR of BRAF completely abolished its interaction with miR-9-5p. Expression of exogenous miRNA that mimics miR-9-5p miRNA decreased BRAF protein and mRNA levels, while suppression of endogenous miR-9-5p resulted in an increase in BRAF protein, and mRNA levels. Furthermore, regulation of miR-9-5p was observed to suppress the viability of PTC cells by inducing apoptosis. Consistently, downregulation of miR-9-5p promoted proliferation of PTC cells by inhibiting the apoptosis of cells. In conclusion, the present study demonstrated that miR-9-5p may perform an important role in PTC prognosis and therapy.

Clinicopathological profile of papillary carcinoma of thyroid: A 10-year experience in a tertiary care institute in North Karnataka, India

CONTEXT

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy accounting for 80% of the thyroid cancers. Many histopathologic variants of PTC have been recognized, and few of these are of prognostic significance. The studies on clinicopathological features of PTC and its variants are so far seldom reported in India.

AIM

The aim of the study was to study the percentage distribution of PTC among total thyroid specimens, the age and sex distribution of PTC, its histopathological features including frequency of nuclear findings, and various histological subtypes are also studied in detail. Methods: All cases of PTC diagnosed in our department from April 2003 to March 2013 formed the material for the study. The tissues were routinely processed and stained. On microscopic examination, tumors were classified according to 2004 WHO classification.

RESULTS

PTC formed the predominant type of malignancy accounting to 71% of the total cases. Of these, about 75% of patients were in the second to fifth decade. Male to female ratio was 1:5.4. Other than the usual classic variant and follicular variant, we also found rare types such as clear cell variant, tall cell type, oncocytic type, and macrofollicular variant. Microscopically, nuclear overcrowding and ground glass nuclei were seen in more than 90% of cases. Nodular goiter, Hashimoto's thyroiditis, and follicular adenoma were associated lesions in some cases.

CONCLUSION

PTC is the most common thyroid malignancy, and it can affect any age group though it presents mostly in the third to fourth decade of life. Recognition of histological subtype is crucial in patient prognosis.

Ubiquitin Immunostaining in Thyroid Neoplasms Marks True Intranuclear Cytoplasmic Pseudoinclusions and May Help Differentiate Papillary Carcinoma from NIFTP

Papillary thyroid carcinoma (PTC) is defined by an invasive growth pattern and classic nuclear features: enlarged, grooved, overlapping nuclei with chromatin clearing and intranuclear cytoplasmic pseudoinclusions (INCP). True INCPs are characteristic of PTC, but may infrequently be seen in noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP). Nuclear abnormalities that mimic INCP ("pseudo-pseudoinclusions") are common in a variety of thyroid lesions. H&E and ubiquitin-stained whole tissue sections of classic PTC (n = 25) and NIFTP (n = 35) were evaluated. On H&E, true INCPs were present in all (100%) PTCs and absent in all NIFTPs (0%). Pseudo-pseudoinclusions were present in 13 (37%) NIFTPs. In 24 (96%) PTCs, ubiquitin was strongly expressed within INCPs. In NIFTPs, optically clear nuclei or pseudo-pseudoinclusions did not express ubiquitin (0/35). Occasionally, nuclear vacuoles in NIFTP demonstrated a marginated staining pattern, in which strong ubiquitin expression was seen at the periphery of the nucleus, but the central pale area was negative. In addition, 2 NIFTPs demonstrated intrafollicular psammomatoid calcifications which were strongly ubiquitin-positive. Psammoma bodies in PTC were ubiquitin-negative in the majority of cases. We report a previously undescribed finding: strong ubiquitin expression in true INCPs in PTC, absence of true INCPs in NIFTP, and absence of ubiquitin expression in pseudo-pseudoinclusions in NIFTP. This finding supports the difference between true INCPs (found only in PTC) and pseudo-pseudoinclusions (found in NIFTP). Using strict histologic criteria and ubiquitin immunostaining, the presence of true pseudoinclusions may exclude a diagnosis of NIFTP. Caution should be exercised when interpreting nuclear vacuoles or pseudo-pseudoinclusions.

Ultrasound features of extranodal extension in the metastatic cervical lymph nodes of papillary thyroid cancer: a case-control study

Objective:

Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer. The purpose of this study was to identify the common and characteristic preoperative ultrasonography features that are associated with the pathologic extranodal extension of metastatic papillary thyroid carcinoma.

Methods:

We retrospectively assessed and compared clinicopathologic and ultrasound features between 60 papillary thyroid cancer patients with extranodal extension and 120 control patients with papillary thyroid cancer without extranodal extension.

Results:

With respect to the pathological N stage and clinicopathologic features, N1b stage papillary thyroid carcinomas were more frequently found in patients who were extranodal extension-positive, in comparison with those who were extranodal extension-negative (78.3% vs. 63.3%, P=0.043). Extranodal extension was detected most frequently in level VI cervical lymph nodes (48.7%). In our univariate analysis of patients with papillary thyroid carcinoma, cervical lymph nodes with extranodal extension showed higher incidences of node matting, microcalcification, cystic area, aspect ratio <2, and larger diameter than those without extranodal extension (all P<0.05). Our multivariate analysis demonstrated that node matting and cystic area were independent risk factors for the presence of extranodal extension [odds ratio (OR): 4.751, 95% confidence interval (CI): 1.212~18.626, P=0.025; OR: 2.707, 95% CI: 1.127~6.502, P=0.026].

Conclusions:

Common ultrasound features may indicate the presence of extranodal extension in patients with metastatic cervical lymph nodes of papillary thyroid carcinoma.

The role of postoperative Tc-99m pertechnetate scintigraphy in estimation of remnant mass and prediction of successful ablation in patients with differentiated thyroid cancer

OBJECTIVE

Surgery and radioactive iodine (RAI) ablation constitute the mainstay of the treatment of differentiated thyroid carcinoma (DTC). In this study, we aimed to evaluate the diagnostic value of postoperative early Tc-99m pertechnetate scanning to detect remnant thyroid tissue and predict ablation success.

METHODS

DTC patients evaluated with postoperative Tc-99m pertechnetate scintigraphy and treated with RAI between January 2007 and December 2014 were recruited. The results of Tc-99m pertechnetate scanning were compared with therapeutic I-131 whole-body scanning (TxWBS) and diagnostic I-131 whole-body scanning (DxWBS) performed 6-9 months after RAI.

RESULTS

There were 154 (21.5%) male and 563 (78.5%) female patients, with a mean age of 49.11±12.35 years. Postoperative Tc-99m pertechnetate scanning was positive in 499 patients (69.6%) and negative in 218 (30.4%) patients. There were 673 (93.9%) patients with a positive TxWBS scan and 44 (6.1%) patients with negative TxWBS scan. Considering TxWBS as the standard test, sensitivity, specificity, positive predictive value, and negative predictive value of Tc-99m pertechnetate scanning were 72.2, 70.5, 97.4, and 14.2%, respectively. DxWBS was positive in 57 (9.0%) and negative in 564 (91%) patients. Ablation dose was higher and preablation thyroglobulin was lower in patients with negative DxWBS (P=0.001 and 0.04, respectively). Overall, 171 (92.9%) of 184 patients with negative Tc-99m pertechnetate had negative DxWBS.

CONCLUSION

Postoperative Tc-99m pertechnetate scintigraphy has a high positive predictive value to detect remnant tissue in patients with DTC. Although negative Tc-99m pertechnetate scanning does not indicate removal of all thyroid tissue, it is related to successful ablation in more than 90% of patients.

Etiopathogenesis of Differentiated Thyroid Carcinomas

INTRODUCTION

Thyroid malignomas are a heterogeneous group of neoplasm consisting of most frequent differentiated encountered carcinomas, papillary and follicular thyroid carcinoma, then medullary thyroid carcinoma originating from neuroendocrine calcitonin-producing C-cells and rare forms of thyroid lymphomas arising from intrathyroidal lymphatic tissue, thyroid sarcomas and poorly differentiated anaplastic thyroid carcinoma. There are increasing numbers of epidemiological studies and publications that have suggested increased incidence rate of thyroid carcinomas. We have read, analysed and compare available reviews and original articles investigating different etiological factors in the development of thyroid carcinomas through Google Scholar and PubMed Database.

DISCUSSION

Aetiology involved in the development of thyroid carcinomas is multifactorial and includes external influences, as well as constitutional predispositions and genetic etiological factors. The actual effect of environmental and constitutional factors is on promoting genetic and epigenetic alterations which result in cell proliferation and oncogenesis. Until now are identified numerous genetic alterations, assumed to have an important role in oncogenesis, with MAPK and PI3K-AKT as crucial signalling networks regulating growth, proliferation, differentiation and cell survival/apoptosis.

CONCLUSION

This new molecular insight could have a crucial impact on diagnosis and also on improving and selecting an appropriate treatment to the patients with thyroid malignancies.

Differential Clinicopathological Risk and Prognosis of Major Papillary Thyroid Cancer Variants

CONTEXT

Individualized management, incorporating papillary thyroid cancer (PTC) variant-specific risk, is conceivably a useful treatment strategy for PTC, which awaits comprehensive data demonstrating differential risks of PTC variants to support.

OBJECTIVE

This study sought to establish the differential clinicopathological risk of major PTC variants: conventional PTC (CPTC), follicular-variant PTC (FVPTC), and tall-cell PTC (TCPTC).

METHODS

This was a retrospective study of clinicopathological outcomes of 6282 PTC patients (4799 females and 1483 males) from 26 centers and The Cancer Genome Atlas in 14 countries with a median age of 44 years (interquartile range, 33-56 y) and median follow-up time of 37 months (interquartile range, 15-82 mo).

RESULTS

The cohort consisted of 4702 (74.8%) patients with CPTC, 1126 (17.9%) with FVPTC, and 239 (3.8%) with TCPTC. The prevalence of high-risk parameters was significantly different among the three variants, including extrathyroidal invasion, lymph node metastasis, stages III/IV, disease recurrence, mortality, and the use (need) of radioiodine treatment (all P < .001), being highest in TCPTC, lowest in FVPTC, and intermediate in CPTC, following an order of TCPTC > CPTC ≫ FVPTC. Recurrence and mortality in TCPTC, CPTC, and FVPTC were 27.3 and 6.7%, 16.1 and 2.5%, and 9.1 and 0.6%, corresponding to events per 1000 person-years (95% confidence interval [CI]) of 92.47 (64.66-132.26) and 24.61 (12.31-49.21), 34.46 (30.71-38.66), and 5.87 (4.37-7.88), and 24.73 (18.34-33.35) and 1.68 (0.54-5.21), respectively. Mortality hazard ratios of CPTC and TCPTC over FVPTC were 3.44 (95% CI, 1.07-11.11) and 14.96 (95% CI, 3.93-56.89), respectively. Kaplan-Meier survival analyses showed the best prognosis in FVPTC, worst in TCPTC, and intermediate in CPTC in disease recurrence-free probability and disease-specific patient survival. This was particularly the case in patients at least 45 years old.

CONCLUSION

This large multicenter study demonstrates differential prognostic risks of the three major PTC variants and establishes a unique risk order of TCPTC > CPTC ≫ FVPTC, providing important clinical implications for specific variant-based management of PTC.

Perfluoroalkylchain conjugation as a new tactic for enhancing cell permeability of peptide nucleic acids (PNAs) via reducing the nanoparticle size

Perfluoro undecanoyl chain conjugated peptide nucleic acids (PNAs) show 2.5 to 3 fold higher cellular uptake efficiency in NIH 3T3 and HeLa cells compared to simple undecanoyl PNAs. Fluorination of PNAs leads to the formation of lower size (∼100-250 nm) nanoparticles compared to larger size (∼500 nm) nanoparticles from non-fluorinated PNAs, thereby improving the efficiency of cell penetration.

Papillary carcinoma of thyroid with an unusual presentation

Papillary thyroid carcinoma is well known for its low malignant potential and good prognosis. The outcome can be fatal in patients with low compliance and delayed treatment. Recent advances in ultrasonographic screening and US guided fine needle aspiration biopsy has facilitated early diagnosis of papillary thyroid carcinomas. This epithelial thyroid tumour accounts for more than 80 % of all thyroid tumours. An occult primary carcinoma of thyroid presenting as lymphangioma has been reported rarely. We present a case of a 40-year-old female patient with huge cystic midline swelling on the right side of the neck mimicking lymphangioma on USG. MRI neck showed a cystic mass causing displacement of the trachea and arising from Rt lobe of thyroid gland. Hemithyroidectomy was carried out and histopathology revealed papillary carcinoma. In patients with neck swellings presenting as huge cystic mass the differential diagnosis of Intra cystic variant of papillary carcinoma thyroid and metastatic thyroid papillary carcinoma must always be considered prior to planning surgery.

Cutaneous metastasis as the presenting sign of papillary thyroid carcinoma

Cutaneous metastasis of visceral tumors accounts for 2% of skin tumors. We report the case of a 71-year-old male with a smoking history who presented to dermatology department with a violaceous nodule of the right sideburn skin. The lesion was interpreted as an adenocarcinoma that was completely excised and was suspicious for a metastasis. There was a recommendation for additional work-up. At a different institution, a positron emission tomography scan showed a left hilar mass and uptake in the right thyroid. He was then referred to our hospital for tissue diagnosis. Mediastinoscopy with biopsy of the left hilar mass showed metastatic follicular thyroid carcinoma. Subsequently, a thyroid fine needle aspirate showed suspicion for malignancy with similar morphology. Thyroidectomy and central neck dissection showed right thyroid papillary carcinoma extending to one margin and involving the lymph nodes. The left hilar metastasis mass resection showed similar lymph node findings. A re-review of the sideburn excision revealed similar histopathology to the thyroid and mediastinal resection. This case illustrates the opportunity of considering metastatic thyroid carcinoma to skin even in cases which lack the classic cytologic and architectural features of papillary thyroid carcinoma follicular variant.

Unusual presentation of cystic papillary thyroid carcinoma

Papillary thyroid carcinoma is the most common thyroid malignancy, accounting for 80% of all thyroid cancers. The most common presentation of thyroid cancer is an asymptomatic thyroid mass or a nodule. Usually as thyroid enlarges, it extends in to mediastinum. Papillary thyroid carcinoma presentation as multiple true cystic swelling extending from neck to anterior chest wall in subcutaneous plane is not present in the literature. We present a rare case of cystic papillary thyroid carcinoma which is presented as subcutaneous swelling with sinus formation.

Matrix metalloproteinase-9 and the Cu/Zn ratio as ancillary diagnostic tools in distinguishing between the classical and follicular variants of papillary thyroid carcinoma

The most common histological variants of papillary thyroid carcinoma (PTC), classical (CPTC) and follicular (FPTC), have different diagnostic features, molecular biology, and prognosis. Matrix metalloproteinase-9 (MMP-9) endopeptidase which degrades the components of the extracellular matrix is essential in the invasive growth and metastasizing of malignant tumors. The serum copper (Cu)/zinc (Zn) ratios are sensitive diagnostic and prognostic indicators in oncology since Cu- and Zn-dependent enzymes play important roles in the genesis and the progression of tumors. The aim of this study was to examine the expressions of MMP-9 in tissues of CPTC and FPTC, as well as to determine the Cu/Zn ratios in the same samples. MMP-9 was determined immunohistochemically, and the concentrations of copper and zinc in thyroid tissue were determined by means of flame atomic absorption spectrometry. The results obtained revealed significantly higher expressions of MMP-9 in CPTC in comparison with FPTC, as well as higher Cu/Zn ratios in CPTC than in FPTC. Thus, determining MMP-9 activities and the Cu/Zn ratios could improve the accuracy of the standard histopathological diagnosis of these two types of PTC.

S-phase fraction and ploidy as predictive markers in primary disease and recurrence of papillary thyroid carcinoma

OBJECTIVE

To investigate the prognostic influence of DNA ploidy and S-phase fraction (SPF) on disease-free (DFS) and overall survival (OS) of patients with primary disease and loco-regional lymph node recurrence of papillary thyroid carcinoma (PTC).

DESIGN

A large prospective study with long-term follow-up (median, 117 months).

PATIENTS

Two series of patients with primary PTC (n = 305) and lymph node recurrence metastasis (LNM) (n = 39) were involved in the study.

MEASUREMENTS

Patient's age and gender, histological variant, pathological tumour-node-metastasis (pTNM) staging, extrathyroidal extension, vascular and lymphatic invasion and tumour bilateral growth were the clinical and pathological characteristics evaluated. DNA flow cytometry was performed on fresh/frozen surgical tumour samples. Cox regression models were estimated for prognostic analyses.

RESULTS

Seventeen (5·6%) primary tumours and five (12·8%) LNMs were aneuploid, while mean SPF was 2·7% and 3·7%, respectively (P = 0·022). High SPF was significantly associated with lymphatic invasion and tall cell and diffuse sclerosing variants. In univariate analysis, all the clinico-pathological variables, but tumour bilateral growth and gender, were significantly correlated with survival. SPF showed borderline significance (P = 0·051) in relation to OS. In multivariate analysis, older age (≥48 years), lymph node spread and high SPF were significantly adverse prognostic factors. Extrathyroidal extension and distant metastasis for OS, as well as tumour size for DFS, were also found as unfavourable prognostic features. In LNM, the Kaplan-Meier curves showed significant differences for older age and DNA aneuploidy (recurrence; P = 0·011).

CONCLUSION

The results indicate that SPF and ploidy can provide additional predictive information in patients with PTC.

Lipid conjugated oligonucleotides: a useful strategy for delivery

Oligonucleotides, including antisense oligonucleotides and siRNA, are promising therapeutic agents against a variety of diseases. Effective delivery of these molecules is critical in view of their clinical application. Therefore, cation-based nanoplexes have been developed to improve the stability as well as the intracellular penetration of these short fragments of nucleic acids. However, this approach is clearly limited by the strong interaction with proteins after administration and by the inherent toxicity of these positively charged transfection materials. Neutral lipid-oligonucleotide conjugates have become a subject of considerable interest to improve the safe delivery of oligonucleotides. These molecules have been chemically conjugated to hydrophobic moieties such as cholesterol, squalene, or fatty acids to enhance their pharmacokinetic behavior and trans-membrane delivery. The present review gives an account of the main synthetic methods available to conjugate lipids to oligonucleotides and will discuss the pharmacological efficacy of this approach.

Chromosomal aberrations in thyroid follicular-cell neoplasia: in the search of novel oncogenes and tumour suppressor genes

Thyroid cancer derived from the follicular cell is characterised by specific gene alterations that are closely linked to the various pathological types comprising papillary, follicular and anaplastic thyroid cancer. However, the correlation between molecular biology and pathology is not absolute, since about 30% of cases do not harbour the typical gene alterations. This situation, coupled with the demonstration of genetic heterogeneity in thyroid cancer, is a strong motivation for the search of novel gene alterations. Chromosomal aberrations are a good starting point to initiate this search and therefore the current knowledge on chromosomal alterations in thyroid follicular-cell neoplasia is reviewed in this article. An overview on molecular cytogenetic approaches for this strategy is also provided. The identification of novel genetic markers in thyroid cancer will be further improved by integrative approaches combining data from genomic and expression analyses with clinical data. This approach is powerful to identify genetic markers as well as new therapeutic targets in follicular-cell thyroid cancer.

Diagnosis and treatment of pancreatic metastases of a papillary thyroid carcinoma

BACKGROUND

Apart from regional lymph node metastases, systemic metastases occur sporadically in papillary thyroid carcinomas (PTC). The lung and bones are the most frequent localizations. Additionally known but extremely rare locations are metastases of the skeletal muscles, ovaries, submandibular gland, sphenoidal sinus, brain, adrenals, and, as shown in only two previously published cases to date, the pancreas.

SUMMARY

In this article we report about two additional patients with pancreatic metastases from PTC. There is almost no prior experience about therapeutic approaches to this type of metastases. In both patients distant metastases within the pancreas were successfully removed. Postoperative histology confirmed the diagnoses. Supplemental genetic analysis did not demonstrate a BRAF V600E mutation or expression of a RET/PTC1 rearrangement in one case, but revealed a BRAF V600E mutation in the second case. Surgery avoided impending complications maintaining quality of life. One patient had a tumor-specific survival of 42 months. The other patient has occult disease.

CONCLUSIONS

Our two patients benefited of a calculated aggressive surgical action. Thus, if low perioperative mortality and morbidity can be warranted, surgical measures are justifiable in selected cases.

Molecular rearrangements in papillary thyroid carcinomas

Papillary thyroid cancer is unusual among epithelial malignancies in that it is associated with a number of chromosomal rearrangements. The most common of these is the Ret oncogene, normally silent in the follicular cell, but which has been shown to be rearranged to the promoter region of a variety of different genes, all of which are constituently expressed in the thyroid follicular cell. It has been suggested that chromosomes in the thyroid cell are arranged within the nucleus in such a way as to predispose the cell to inappropriate fusion in the advent of DNA double-strand breakage. The presence of tumour specific fusion genes, and their transcribed proteins, presents a possible therapeutic target for thyroid cancer, but the relative contribution of the gene rearrangement in the growth and development of the tumour will need careful evaluation before clinical studies could take place.

Clinical implications of molecular markers in follicular cell-derived thyroid cancer

The increasing use/applications of molecular biology techniques have provided new insights on the genetic changes that underlie carcinogenesis and tumor progression in thyroid cancer. Molecular analysis may improve the histopathologic evaluation of follicular cell-derived thyroid carcinoma, not only elucidating some unresolved problems related to the diagnosis and disease prognosis, but also by improving patient management. Besides increasing our comprehension of cancer biology, either genetic alterations or gene expression profiles implicated in thyroid carcinogenesis shed new light on innovative diagnostic procedures as well as on targeted therapies.

What is your diagnosis? Intracranial mass in a dog

A 9-year-old, spayed female Chihuahua was presented for evaluation of acute, progressive neurologic disease. On physical examination the dog was depressed and laterally recumbent. The dog had marked neutrophilia with a toxic left shift and monocytosis. Using computed tomography with contrast enhancement a large intracranial mass lesion was identified in the rostral portion of the brain. The mass extended from the central thalamic region rostral to the cribiform plate and obliterated the lateral ventricles. A fine needle aspirate of the mass contained moderately pleomorphic polygonal cells with many intranuclear cytoplasmic pseudoinclusions (ICPs). The primary differential diagnosis was meningioma, based on cell morphology and the presence of ICPs. At necropsy, the mass was well-demarcated, unencapsulated, and densely cellular. Cells were arranged in papillary projections on fibrovascular stalks, and eosinophilic ICPs and nuclear folding were frequently seen. Cavitated areas of necrosis throughout the tumor mass were filled with intact and degenerated neutrophils. The histopathologic diagnosis was malignant papillary meningioma. ICPs are not frequently observed in Wright-stained cytologic preparations but may be found in many types of neoplasms, including meningiomas.

Multinucleated giant cells' incidence, immune markers, and significance: a study of 172 cases of papillary thyroid carcinoma

Multinucleated giant cells (MGCs) are often detected in cases of papillary thyroid carcinoma (PTC). Their origin and significance, however, has not been established. One possibility is that they form in response to injury induced by fine needle aspiration biopsy (FNAB). Other hypotheses are that the chemically-altered colloid produced by PTC induces MGCs to act as colloidophages, or else MGCs are a non-specific immune response ingesting neoplastic follicle cells. We assigned 172 cases of PTC a semi-quantitative score for MGCs. Cases with "many" MGCs were immunohistochemically stained for AEI/AEIII, CD68, and CD163 to assess for epithelial vs histiocytic differentiation, and for thyroglobulin and TTF-1 to assess for MGC ingestion of colloid or thyroid follicle cells respectively. Overall, we identified MGCs in 100/172 (58.1%) PTC specimens; in 45 (26.2%), "many" MGCs were found, while in 55 (31.9%) MGCs were "few." The mean sizes of PTC in cases with many as opposed to rare/no MGCs was 2.50 cm vs 1.8 [P = 0.003]. The cases of PTC with many MGCs had higher multifocality (26/45 vs 51/127 [P = 0.06]), extrathyroidal extension (21/45 vs 36/127 [P = 0.03]), and recurrence (8/45 vs 9/127 [P = 0.08]), than did cases with rare or no MGCs. The majority of patients both with and without numerous MGCs had previous histories of FNA or hemilobectomy: 40/45 and 99/127 respectively (P = 0.062). The majority of MGCs were positive for CD68 (45/45), CD163 (44/45), thyroglobulin (34/45) and negative for AEI/AEIII (44/45) and TTF-1 (44/45). These results indicate that MGCs in PTC are of histiocytic origin. Cases of PTC with many MGCs have a significantly greater likelihood of extrathyroidal extension and greater tumor size than cases with few/no MGCs. MGCs appear to be functioning largely as colloidophages.

What is New on Thyroid Cancer Biomarkers

Thyroid cancer harbours in about 5% of thyroid nodules. The majority of them are well-differentiated cancers originating from the follicular epithelium, and are subdivided into papillary and follicular carcinomas. Undifferentiated carcinomas and medullary thyroid carcinomas arising from C cells are less common.

Although most thyroid nodules are benign, distinguishing thyroid cancer from benign lesions is crucial for an appropriate treatment and follow-up. The fine needle aspiration cytology (FNAC) allows the diagnosis of nature of thyroid nodules in the majority of cases. However, FNAC has some limitations, particularly in the presence of follicular lesions which can appear dubious in rare instances even at histology.

In an effort to improve diagnostic accuracy and offer new prognostic criteria, several immunohistochemical and molecular markers have been proposed. However, most of them have to be validated on large series before being used in routine practice.

Branchial cleft cyst as the initial impression of a metastatic thyroid papillary carcinoma: two case reports

Branchial cleft cysts are the most common lesions in lateral neck cysts, predominantly occurring in the fourth decade of life and without sexual propensity. Rare branchial cleft cysts are associated with malignant tumors metastatic from the oral cavity, nasal cavity, pharynx or thyroid gland. Occult thyroid papillary carcinomas often present as a solid mass in the lateral neck, with only a few cases revealing a branchial cleft cyst as the initial manifestation. Herein, we report two cases of metastatic thyroid papillary carcinoma that presented as lateral neck cysts, with preoperative diagnosis of branchial cleft cyst. Finally, after complete surgical resection and histopathologic examination, one case was diagnosed as cystic change of metastatic lymph node from thyroid papillary carcinoma, and the other was determined to be a branchial cleft cyst with concurrent lymph node metastasis from thyroid papillary carcinoma. When a branchial cleft cyst is diagnosed by clinical or histopathologic examination, a metastatic thyroid papillary carcinoma should be considered as part of the differential diagnosis.

Increased P2X7 receptor expression and function in thyroid papillary cancer: a new potential marker of the disease?

Nucleotides are increasingly recognized as nonredundant extracellular signals for chemotaxis, cell growth, and cytokine release. Effects of extracellular nucleotides are mediated by P2 receptors, among which the P2X(7) subtype is attracting increasing attention for its involvement in apoptosis, cell growth, and cytokine release. Recent studies showed that P2X(7) is overexpressed in chronic lymphocytic leukemia and breast and prostate cancer. The aim of the present study was to better understand the clinical significance of P2X(7) receptor expression in normal and cancer human thyroid tissues. P2X(7) receptor message and protein expression and functional activity were tested in two cell lines (FB1 and FB2) established from either anaplastic or papillary primary thyroid cancer and in several histological samples of human papillary cancer. We show here that human thyroid papillary carcinoma, whether of the classical or follicular variant, expresses the P2X(7) receptor (P2X(7)R) to a much higher level than normal thyroid tissue. The P2X(7)R was similarly up-regulated in FB1 and FB2 cell lines. In contrast to normal thyroid cells, both cell lines responded to extracellular nucleotide stimulation with a large increase in intracellular Ca(2+) and secretion of IL-6. Ca(2+) increase was attenuated and release of IL-6 was fully blocked by P2X(7)R inhibitors. Finally, the thyroid carcinoma cell lines had at least a 3-fold higher intracellular ATP concentration and maintained at least a 3-fold higher extracellular ATP level, compared with control cells. These data suggest that an enhanced P2X(7)R function might be a feature of human thyroid cancer.

siRNA nanoformulation against the ret/PTC1 junction oncogene is efficient in an in vivo model of papillary thyroid carcinoma

Delivery is a very important concern for therapeutic applications of siRNA. In this study, we have used chitosan-coated poly(isobutylcyanoacrylate) nanoparticles to deliver siRNA with a complementary sequence to the fusion oncogene ret/PTC1. By screening the mRNA junction we have selected a potent siRNA sequence able to inhibit this oncogene in a model of Papillary Thyroid Carcinoma cells. This siRNA sequence has then been validated by a shRNA approach using the same sequence. Furthermore, the high ret/PTC1 inhibition has triggered a phenotypic reversion of the transformed cells. We have designed well-defined chitosan decorated nanoparticles and succeeded to reduce their size. They have allowed to protect ret/PTC1 siRNA from in vivo degradation and leading to significant tumour growth inhibition after intratumoral administration.

Genetic polymorphism of CYP2D6 influences susceptibility to papillary thyroid cancer

OBJECTIVE

Xenobiotic-metabolizing enzymes are widely polymorphic and confer interindividual variation in the ability to detoxify carcinogens or to activate pro-carcinogens. A common polymorphism of cytochrome P450 2D6 (CYP2D6) results in lack of enzyme activity and has been associated with an altered susceptibility to several cancers. The aim of this study was to investigate the association between the CYP2D6 poor metaboliser genotype and the risk of papillary thyroid cancer (PTC).

DESIGN

Retrospective case-control study.

PATIENTS

One hundred and eighty-seven patients with PTC and 256 controls.

MEASUREMENTS

Genotyping was performed by PCR and restriction enzyme analysis to detect the presence of the common CYP2D6*4 poor metaboliser allele.

RESULTS

The frequency of individuals with the homozygous poor metaboliser genotype was lower in the patient group [1.6 vs. 5.5%, P = 0.037, OR = 0.28 (95% CI 0.09-0.93)]. The CYP2D6*4 allele frequency was also lower in the patient group [13.4 vs. 21.7%, P = 0.002, OR = 0.56 (95% CI 0.39-0.80)].

CONCLUSIONS

The results suggest that the poor metaboliser genotype is associated with a protective effect against PTC. This could be explained by a possible role of CYP2D6 on the metabolic activation of putative environmental chemical thyroid carcinogens or by linkage to another cancer-causing gene. Further research may allow the identification of metabolic risk factors and contribute towards understanding the molecular mechanisms involved in thyroid carcinogenesis.

Immunohistochemistry differentiates papillary thyroid carcinoma arising in ectopic thyroid tissue from secondary lymph node metastases

OBJECTIVE

To verify whether immunohistochemistry might be useful in the distinction between a true laterocervical metastasis of an undetected thyroid carcinoma and a primary tumor outside the gland.

DESIGN

Galectin-3, cytokeratin 19, and HBME-1 were assessed in six cases (group A) of laterocervical masses harboring papillary thyroid carcinoma (PTC) but without a thyroid tumor, and in eight cases (group B) showing PTC both in the thyroid and in the laterocervical masses. In both groups, normal-looking follicles adjacent to the laterocervical neoplasia were present.

MAIN OUTCOME

We found that the apparently normal follicles in group A were negative for all the antibodies, while group B showed strong and diffuse positive immunostaining. The neoplastic areas were always positive for all the antibodies in both groups.

CONCLUSION

Even if immunohistochemical patterns of residual follicles of group B are very well differentiated that they resemble normal thyroid parenchyma, they may well be metastatic carcinomas. On the contrary, the presence of morphologically and immunohistochemically normal-looking follicles in group A, with no intrathyroid tumor, suggests that the primary PTC might possibly develop in the ectopic thyroid tissue. In cases showing morphologically and immunohistochemically normal-looking follicles in laterocervical masses, these findings might lead to a reduction of the overdiagnosis of metastatic disease of an undetected carcinoma.

Papillary Thyroid Carcinoma With Thyroid-associated Orbitopathy in a Euthyroid State

PURPOSE

Thyroid cancers with concurrent thyroid-associated orbitopathy (TAO) are extremely rare. The present study reports 5 unusual cases of papillary thyroid microcarcinoma in patients presenting with TAO in an euthyroid state.

METHODS

We retrospectively reviewed the records of 5 patients (4 female, 1 male) with no known history of thyroid disease, who initially presented with TAO and were subsequently found to have thyroid cancer. TAO was diagnosed by a combination of computed tomography and clinical symptoms and signs. All patients underwent routine serologic assessment of thyroid hormones and thyroid-related autoantibodies including thyrotropin-receptor antibodies, as well as imaging studies such as neck ultrasonography or thyroid scintiscan with I.

RESULTS

Patients presented with asymmetric proptosis (cases 1-3), ocular motility restriction (cases 1-3), and eyelid retraction (cases 1-5). None of the patients showed clinical signs of hyperthyroidism, and all returned normal thyroid function test data. Thyroid nodules were detected by neck imaging; subsequent fine-needle aspiration biopsies were performed with the cytologic result of papillary carcinoma. In no cases did ophthalmic symptoms resolve following cancer treatment (e.g., thyroidectomy and radioactive iodine therapy). All patients were positive for thyroid-binding inhibiting immunoglobulin in low titers.

CONCLUSIONS

Although coincident occurrence is rare, patients presenting with TAO should be carefully evaluated for the possible presence of papillary microcarcinoma, which can develop in a setting of systemic autoimmunity without inducing hyperthyroidism.