Hyperplastic Thyroid Research Articles

Histochemical Investigation of Cyanogenic Toxicity in the Thyroid Epithelial Cells and Follicles of Thyroid Gland in Adult Female Wistar Rats

Aim: This study was aimed at understanding the earlier findings involving chronic, lowlevel cyanide exposure resulting from eating poorly processed cassava products associated with the development of goitre as seen in cassava endemic regions of Nigeria. Study Design: 30F1 female adult Wistar rats were divided into five (5) groups of 6 animals each. Groups 1 to 4 represented the treatment groups while group 5 was the Original Research Article British Journal of Medicine & Medical Research, 4(8): 1750-1762, 2014 1751 control of the experiment. The cyanide treatment dose were; group1: 20mg/KgBW, group 2: 12mg/KgBW, group 3: 6mg/KgBW and group 4: 2mg/KgBW while the control group received 0.25M Sucrose. Place and Duration of Study: The animal facility of College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria. The treatment duration was 30days. Methodology: Animals were sacrificed by cervical dislocation. The blood samples were collected to determine Serum FT3, FT4 and TSH concentration. The thyroid gland was excised and processed for light microscopic examination; while the activities of G6PDH, LDH, ALP, MDA and SOD were assayed from the thyroid tissue homogenates. Results: Histological observation of thyroid gland of rats from the experimental treated groups revealed markedly distended follicles and diffusely hyperplastic thyroid follicles lined with tall columnar epithelial cells. These thyroid epithelial cells are crowded and enlarged projecting into the lumens of their respective follicles. Their interstitial tissue all had dilated blood vessels. Application of one-way ANOVA statistical analytical method showed that there were highly significant differences P˂0.05 in the activities of G6PDH, LDH, ALP, MDA, SOD, FT3, FT4 and TSH when compared with those of the control group. Conclusion: The results obtained from this study showed hyperthyroidism was effectively induced by cyanide.

The Unique Utility of EUS in Diagnosis of Substernal Retroesophageal Thyroid Masses

Purpose: A 58-year-old female presented with stabbing chest pain, fatigue, and dysphagia of approximately 3 months. Cardiac work-up was negative. CT demonstrated a 3.5 x 2.1 cm mass in the left retroesophageal space of the superior mediastinum. Barium swallow revealed evidence of extrinsic compression on the upper esophagus at the level of the thoracic inlet. PET scan revealed hypermetabolic activity in the setting of an exophytic posterior thyroid nodule, with normal iodine thyroid uptake scan. EUS was performed with transesophageal FNA biopsy. A single oval mass lesion was found in the superior mediastinum with the echoendoscope positioned at 20 cm from the incisors. The mass was hypoechoic and lobulated measuring 35 x 30 mm. FNA was preceded by color Doppler imaging to confirm a lack of significant vascular structures within the path of aspiration. Cytology revealed Hurthle Cell type hyperplastic thyroid tissue. The patient underwent a substernal total thyroidectomy to relieve her compressive symptoms from the large multi-nodular goiter and to definitively evaluate for malignancy given the abnormal cytology on EUS w/FNA. Final surgical pathology revealed multifocal stage III (T3N0M0) papillary thyroid carcinoma. The patient has been doing well since undergoing thyroidectomy. Literature regarding thyroid cancer with extension of tissue in the retroesophogeal region is quite rare. This very atypical anatomy presents a challenge in diagnosis via conventional approaches such as extracutaneous ultrasound-guided biopsy (1). EUS allows for visualization and biopsy of substernal thyroid masses in retroesophageal and lateral distributions that would otherwise not be accessible by traditional methods. Use of EUS guided FNA in superior mediastinal presenting thyroid masses was first reported only within this past decade (2), making it quite the novel tool in evaluation of such masses. This case serves as an added example to solidify the role of EUS in exploration of thyroid lesions that would otherwise pose a diagnostic dilemma, potentially eliminating the need for a higher risk surgical intervention (3).

RTN4IP1Is Down-Regulated in Thyroid Cancer and Has Tumor-Suppressive Function

Previously we identified RTN4IP1 to be differentially expressed in thyroid cancer by sex and the gene is located on chromosome 6q21, a chromosomal region frequently deleted or with loss of heterozygosity in a variety of human malignancies including thyroid cancer. Because the expression and function of this gene is unknown, we sought to characterize its expression in normal, hyperplastic, and benign and malignant thyroid tissue samples and to evaluate its function in cancer cells. RTN4IP1 expression was analyzed in normal and hyperplastic thyroid tissue and benign and malignant thyroid tissue samples. In 3 thyroid cancer cell lines (TPC1 from a papillary thyroid cancer, FTC133 from a follicular thyroid cancer, XTC1 from a Hürthle cell carcinoma), small interfering RNA knockdown of RTN4IP1 was used to determine its role in regulating the hallmarks of malignant cell phenotype (cellular proliferation, migration, apoptosis, invasion, tumor spheroid formation, anchorage independent growth). We found RTN4IP1 mRNA expression was significantly down-regulated in follicular and papillary thyroid cancer as compared with normal, hyperplastic, and benign thyroid neoplasms (P < .05). Moreover, RTN4IP1 mRNA expression was significantly lower in larger papillary thyroid cancers (P < .05). Small interfering RNA knockdown of RTN4IP1 expression increased cellular proliferation (2- to 4-fold) in all 3 of the cell lines tested and increased cellular invasion (1.5- to 3-fold) and migration (2- to 7.5-fold), colony formation (3- to 6-fold), and tumor spheroid formation (P < .05) in 2 of the 3 cell lines tested (FTC-133 and XTC1). This is the first study to characterize the expression and function of RTN4IP1 in cancer. Our results demonstrate RTN4IP1 is down-regulated in thyroid cancer and is associated with larger papillary thyroid cancer and that it regulates malignant cell phenotype. These findings, taken together, suggest that RTN4IP1 has a tumor-suppressive function and may regulate thyroid cancer progression.

Role of TSH in the spontaneous development of asymmetrical thyroid carcinoma in mice with a targeted mutation in a single allele of the thyroid hormone-β receptor.

Mutations of the thyroid hormone receptor-β gene (THRB) cause resistance to thyroid hormone (RTH). A mouse model of RTH harboring a homozygous thyroid hormone receptor (TR)-β mutation known as PV (Thrb(PV/PV) mouse) spontaneously develops follicular thyroid cancer (FTC). Similar to RTH patients with mutations of two alleles of the THRB gene, the Thrb(PV/PV) mouse exhibits elevated thyroid hormones accompanied by highly nonsuppressible TSH. However, the heterozygous Thrb(PV/+) mouse with mildly elevated TSH (~2-fold) does not develop FTC. The present study examined whether the mutation of a single allele of the Thrb gene is sufficient to induce FTC in Thrb(PV/+) mice under stimulation by high TSH. Thrb(PV/+) mice and wild-type siblings were treated with propylthiouracil (PTU) to elevate serum TSH. Thrb(PV/+)mice treated with PTU (Thrb(PV/+)-PTU) spontaneously developed FTC similar to human thyroid cancer, but wild-type siblings treated with PTU did not. Interestingly, approximately 33% of Thrb(PV/+)-PTU mice developed asymmetrical thyroid tumors, as is frequently observed in human thyroid cancer. Molecular analyses showed activation of the cyclin 1-cyclin-dependent kinase-4-transcription factor E2F1 pathway to increase thyroid tumor cell proliferation of Thrb(PV/+)-PTU mice. Moreover, via extranuclear signaling, the PV also activated the integrin-Src-focal adhesion kinase-AKT-metalloproteinase pathway to increase migration and invasion of tumor cells. Therefore, mutation of a single allele of the Thrb gene is sufficient to drive the TSH-simulated hyperplastic thyroid follicular cells to undergo carcinogenesis. The present study suggests that the Thrb(PV/+)-PTU mouse model potentially could be used to gain insights into the molecular basis underlying the association between thyroid cancer and RTH seen in some affected patients.

Использование фитотерапии при лечении заболеваний щитовидной железы

The main tasks during treatment of hyperplastic thyroid diseases – to stop the growth of thyroid nodules; compensation of hypothyrosis; normalization of thyroid size. One of the perspective methods in combine therapy of diffuse and mix goiter is a phytotherapy. The most often for thyroid diseases we have used the plant drug Polentilla alba, which on Ukrainian market was registered as "Alba®". Investigation has shown, that phytodrug of Polentilla alba could be recommended for monotherapy and for combine conservative therapy of diffuse and mix benign euthyroid goiter, and also for complex treatment of toxic and hypothyroid goiters.

Thyroiditis Associated With Peginterferon α-2A in A Patient with HBeAg Positive Chronic Hepatitis B

Interferon (IFN) lar antiviral etkinliginden dolayi kronik viral hepatit tedavisinde kullanilan protein yapidaki maddelerdir. Tedavi amaciyla kullanimlari sirasinda tiroid fonksiyon bo- zukluklarina sebep olabilmektedirler. Otuz uc yasinda erkek hastaya HBeAg (+) kronik hepatit B tanisiyla PEG- IFN α-2a 120 mcg s.c./hafta tedavisi baslanildi. Tedavi baslangicinda tiroid stimulan hormon (TSH), serbest T3 (ST3), serbest T4 (ST4) duzeyleri normal, antinukleer antikor (ANA) negatif idi. Tedavinin altinci ayinda hastanin; TSH 60.52 (↑), FT3 4.06 (N), FT4 4.48 (↓), Tiroglobulin (TG) 1.6 ng/ml (N), anti- tiroglobulin antikor (ATA) 631 IU/ml (↑), anti-mikrozomal antikor (AMA) 1000IU/ml (↑) olarak tespit edildi. Tiroid ultrasonografisinde; bilateral hipoekoik olan tiroid parenkimi icerisinde fibroz septalar (psodolobulasyon) ve artmis kan- lanma (Hashimato tiroiditi ?) goruldu. Tiroid sintigrafisinde; non-homojen hiperplazik tiroid glandi ve sol lobta hiperaktif nodul tespit edildi. Tiroid biyopsisi; benin sitoloji olarak degerlendirildi. Hastada interferona bagli hashimato tiroiditi dusunulerek IFN tedavisi kesildi ve lamivudin tedavisine gecildi. Hastaya iyatrojenik hipertiroidi nedeniyle levotiron 1x1 tedavisi baslanildi. Levotiron tedavisinin 3. ayinda TSH 0.190, ST3 5.6, ST4 21.24 olarak saptandi ve levotiron kesildi. Interferon tedavisi kesildikten 6 ay sonra yapilan tetkiklerin- de TSH 0.742, ST3 5.33, ST4 14.53 idi. Daha sonraki takiple- rinde tiroid fonksiyonlarinda bozukluk tespit edilmedi. Interferons are used to treat chronic viral hepatitis, due to antiviral activity, are substances of protein structure. IF can lead to disorders of thyroid function during their use for treatment. PEG-IFN α-2a 120 mcg sc / week to thirty-three- year-old male patient was started with the diagnosis of HBeAg (+) chronic hepatitis B. In the beginning of treatment, thyroid stimulating hormone (TSH), free T3 (FT3), free T4 (FT4) levels were normal and antinuclear antibody (ANA) was negative. In the sixth month of treatment the patient's; TSH was 60.52 (↑), FT3 was 4.06 (N), FT4 was 4.48 (↓), thyroglobulin (TG) was 1.6 ng / ml (N), anti-thyroglobulin antibody (ATA) was 631 IU / ml (↑), anti-microsomal anti- body (AMA) was 1000IU/ml (↑). Thyroid ultrasonography revealed bilateral hypoechoic fibrous septa (pseudolobula- tion) and increased blood flow (Hashimoto's thyroiditis? ) in the thyroid parenchyma. In Thyroid scintigraphy; nonhomo- geneous hyperplastic thyroid gland and hyperactive nodule in left lobe were seen. The result of thyroid biopsy were evaluated as benign cytology. Hashimoto's thyroiditis asso- ciated with interferon was thought. Later, IFN therapy was discontinued and lamivudine was started. Due to iatrogenic hyperthyroidism for the patient, levotiron 1x1 was started. In third months of levotiron therapy, TSH was 0.190, T3 was 5.6, T4 was 21: 24. Levotiron treatment was stopped. In 6 months after discontinuation of interferon therapy TSH was 0742, FT3 was 5: 33, FT4 was 14: 53. There was no thyroid disfunction in follow-up of the patient.

Genetic Background May Confer Susceptibility to PTC in Benign Multinodular Thyroid Disease

Purpose: The incidence of hyperplastic thyroid nodular disease has been consistently rising over the last decades. In addition, unsuspected papillary thyroid carcinoma (PTC) can be found in up to 34% of patients operated for benign thyroid lesions. PTC tends to occur multi-focally and is commonly of polyclonal origin. We set out to test the hypothesis that in benign thyroid disease, a unique genetic signature can already be identified in the benign pathology, which is associated with a susceptibility of the thyroid tissue to neoplastic transformation in the context of additional growth promoting stimuli. Patients and Methods: We obtained a set of 23 samples from patients with multinodular goiter (MNG), 12 of whom also harbored an unsuspected PTC. We used global gene expression analysis to evaluate for dissimilarities in the gene expression patterns between these two groups. We also compared these patterns to the profiles of 3 normal thyroid and 7 PTC samples. Results: We were able to accurately distinguish between hyperplastic nodules of patients with multinodular goiter and those that were associated with a PTC. One of the strongest differentially expressed genes, CDC42, has been implicated to respond to environmental factors such as UVB radiation and might point to novel factors contributing to PTC genesis in the setting of pre-existing benign proliferative disease. Conclusion: While the comparison between histologically identical samples cannot distinguish the two groups of goiters, unsupervised or supervised approaches allowed us to identify a molecular signature associated with PTC susceptibility in multinodular goiter.

CDC23 regulates cancer cell phenotype and is overexpressed in papillary thyroid cancer

Cancer gender disparities have been observed for a variety of human malignancies. Thyroid cancer is one such example where there is a dramatic difference in the incidence, aggressiveness, and death rate by gender. The molecular basis for gender disparity is poorly understood. To address this, we performed genome-wide gene expression profiling in matched papillary thyroid cancer (PTC) samples and identified nine candidate genes differentially expressed by gender. One of these genes was CDC23 that was upregulated in PTC in men compared with women. Because the function and expression of CDC23 is unknown in eukaryotic cells, we further characterized the expression of CDC23 in normal, hyperplastic, and PTC tissue samples. We found CDC23 was overexpressed in PTC and absent in normal and hyperplastic thyroid tissue. In thyroid cancer cells, functional knockdown of CDC23 resulted in an increase in the number of cells in both the S and G(2)M phases of the cell cycle, and an inhibition of cellular proliferation, tumor spheroid formation, and anchorage-independent growth. Cellular arrest in both S and G(2)M phases was associated with significant cyclin B1 and securin protein accumulation after CDC23 knockdown. Moreover, the effect of CDC23 on cellular proliferation and cell cycle progression was reversed on triple knockdown studies of CDC23, cyclin B1, and securin. Our data taken together suggests CDC23 has important biologic effects on cell proliferation and cell cycle progression. The effect of CDC23 on cellular proliferation and cell cycle progression is mediated, at least in part, by cyclin B1 and securin protein levels. Therefore, we propose that CDC23 is a critical regulator of cell cycle and cell growth, and may be involved in thyroid cancer initiation and progression, and may explain the different tumor biology observed by gender.

Neurofibromatosis and Esophageal Adenocarcinoma: A Single Case Study

Purpose: Introduction: Neurofibromatosis type-1, also known as von Recklinghausen's disease, is a common autosomal dominant condition manifesting in approximately one in 3000 births. It is well documented that neoplasms arise in up to 25 percent of these patients and are typically of neural-crest origin, including carcinoids, neurofibromas, and gangliomas. However, the occurrence of neurofibromatosis with esophageal adenocarcinoma is exceedingly rare and has not been documented in over twenty years. Case Report: We present a unique case of neurofibromatosis type-I and esophageal adenocarcinoma in a 62-year-old Caucasian male admitted with a three-month history of nausea, vomiting, and seventy-pound weight loss. Risk factors include male gender and positive smoking history of a half a pack per day for forty years. Comorbidities included, but were not limited to pulmonary neurofibromas, emphysema, bilateral nonmalignant adrenal lesions, and hyperplastic thyroid nodules. On admission, CT scan of the abdomen showed distal esophageal thickening concerning for malignancy. EGD revealed a six-centimeter distal esophageal mass obstructing the lumen and extending into the gastroesophageal junction, 32cm from the incisors. The mass had a friable, ulcerated area that was biopsied. Histological findings confirmed moderately differentiated adenocarcinoma. The patient was not a surgical candidate so an esophageal stent and percutaneous endoscopic gastrostomy tube were placed. The patient endured a lengthy and complicated hospital course, culminating with death six weeks after admission. Discussion: Only one case report by Desigan et al from 1985 has documented the presence of esophageal adenocarcinoma in a patient with neurofibromatosis. The coexistence of these two entities is either exceedingly rare or significantly under-reported. Because of the increased incidence of malignancy (including esophageal) in this population, esophageal adenocarcinoma must be considered in the evaluation of nausea, vomiting, and weight loss in patients with neurofibromatosis.

Spotlight

Jiang et al., pp. 505–512 Each year, about 30,000 Americans are diagnosed with oral squamous cell carcinoma. In roughly 40%, the disease starts on the floor of the mouth or on the lateral and ventral surfaces of the tongue. This subtype is significantly more aggressive than tumors at other intraoral locations; tongue cancer spreads rapidly, is highly invasive and often recurs after treatment. Jiang and colleagues recently identified microRNA-138 (miR-138) as a novel regulator of metastatic growth in tongue cancer cells. Significantly lower levels of miR-138 were observed in the highly invasive UM1 cell line than in the less invasive sister cell line UM2 established from the same patient. In this study, the authors pinpoint the molecular targets of miR-138. They uncovered a total of 86 potential cellular targets of miR-138 using bioinformatics prediction programs. Three of the candidates were associated with the family of Rho GTPases, well-known regulators of cell shape, polarity and locomotion. From the 3 hits, RhoC, one of three human Rho-GTPases, and ROCK2, a Rho-associated kinase, were confirmed as bona fide miR-138 targets using standard reporter assays and microRNA inhibitors. Consistent with a role of miR-138 in intracellular actin dynamics, different patterns of stress fiber formation were observed in the UM1 versus UM2 cell lines when expression levels of miR-138 were modified. These findings support a model in which miR-138 functions as a novel multifunctional regulator of cancer cell invasion and as a potential new target for therapeutic intervention in tongue cancer patients. Hombach-Klonisch et al., pp. 521–531 Insulin-like peptide 3 (INSL3) is produced mainly in gonadal tissues and is known for its role in intraabdominal testicular descent in boys. Ectopic expression of INSL3 was found in several tumors but the functional relevance of this expression is largely unknown. Hombach-Klonisch and colleagues reported recently that INSL3 is expressed in hyperplastic thyroid adenoma and thyroid cancer cells but that it is strikingly absent in the normal thyroid gland. In this issue of IJC, the authors identify the molecular program associated with INSL3 action in thyroid cancer cells, a program leading to enhanced tumor invasion and neovascularization. Transcripts for RXFP2, the receptor of INSL3, were detected in tissue samples from thyroid cancer patients, supporting the model that the INSL3/RXFP2 axis is functional in these tissues. Interestingly, RXFP2 gene expression was also detected in normal thyroid tissue, mainly in follicular epithelial cells, where INSL3 is absent. Thyroid cancer cells expressing INSL3 produced increased amounts of the multifactorial Ca2+-binding protein S100A4 known to increase motility and metastasis of cancer cells. Recombinant S100A4 in nanomolar concentrations promoted the formation of microvessel tubes by human umbilical vein endothelial cells similar to vascular endothelial growth factor (VEGF). The authors conclude that in the cancerous thyroid gland, INSL3 adopts the role of an autocrine/paracrine growth factor with potent tissue remodeling and angiogenic properties. Saarinen et al., pp. 737–745 Soy protein, known for its high level of dietary phytoestrogens, may not be the best choice for women who are worried about breast cancer. A new study by Saarinen and colleagues reports that the main phytoestrogenic ingredient in soy protein, genistein, lacks protective properties against breast cancer. Because of structural similarities with 17-β-estradiol, phytoestrogens can either mildly mimic or antagonize the hormone's effects on breast cancer development. In contrast to genistein, the authors find that enterolactone, the main metabolite of plant lignans and the main source of phytoestradiol in the Western diet has beneficial effects and inhibits estrogen-induced growth and angiogenesis in a murine model of human breast cancer. The main sources of dietary enterolactone include flaxseeds, cereals, vegetables and berries. Because of molecular similarities with 17- β-estradiol, phytoestrogens can either mildly mimic or antagonize the hormone's effects on breast cancer development. In estrogen-exposed mice transplanted with the estrogen receptor-positive MCF-7 breast cancer cell line, enterolactone ingestion decreased the release of VEGF derived from the human cancer cells and the murine stroma, resulting in reduced microvessel density of the tumors. In addition, estradiol-induced endothelial cell infiltration was inhibited in mice fed enterolactone but not in those on a genistein-based diet. The combination of enterolactone and genistein had the same beneficial effects as enterlactone alone added to the food.

Biallelic p.R2223H Mutation in the Thyroglobulin Gene Causes Thyroglobulin Retention and Severe Hypothyroidism with Subsequent Development of Thyroid Carcinoma

Dyshormonogenesis due to genetic defect in thyroglobulin (Tg) synthesis and secretion can lead to congenital hypothyroidism. The aim of the study was to analyze the TG gene for the presence of mutations and to study the underlying mechanisms leading to dyshormonogenesis. Two siblings aged 25 and 31 yr presented with recurrent goitrous hypothyroidism with undetectable serum Tg. The older sibling was diagnosed with follicular variant of papillary thyroid carcinoma (FVPTC) at age 21 and metastatic FVPTC 8 yr later. The entire coding region of TG gene was sequenced. BRAF, RAS, and P53 mutations or PAX8/PPAR-gamma rearrangement were screened in the FVPTC. Tg expression was studied by immunohistochemistry. Biallelic c.6725G>A (p.R2223H) and c.6396C>T (p.S2113L) sequence variations were detected in both patients and monoallelic variations in their family members. The c.6396C>T (p.S2113L) sequence variation was found in 14% of 100 population controls, whereas c.6725G>A variation was not present in the controls. Two previously reported polymorphisms (c.2200T>G and c.3082A>G) were present in all the family members. Strong cytoplasmic immunostaining of Tg was observed in the hyperplastic thyroid epithelial cells and weak or no staining in the follicular lumen. Cytoplasmic staining was localized in the endoplasmic reticulum. Reduced staining was found in the FVPTC. Neither RAS, BRAF, or P53 gene mutation nor a PAX8/PPAR-gamma rearrangement was detected in the tumor tissue. Biallelic c.6725G>A (p.R2223H) mutation causes Tg retention in the endoplasmic reticulum, resulting in dyshormonogenesis. Prolonged TSH stimulation may promote malignant transformation and development of thyroid cancer. The c.6396C>T (p.S2113L) is a novel polymorphism.

Growing thyroid nodules with benign histology and RET rearrangement

Some benign thyroid nodules are stationary in size over time while others grow progressively, indicating that there is a broad individual variability within benign nodules. To date, it is very difficult to predict if a benign thyroid nodule will grow in size and which will be its trend over time. While BRAF(V600E) is a highly specific marker of thyroid cancer, RET rearrangements have been disclosed also in non malignant thyroid lesions and their biological significance is debated. We compared the clinical history of three histologically benign thyroid nodules harboring RET rearrangements with that of 6 benign nodules bearing wild type RET. The nodules negative for RET rearrangements were followed for 10 years by ultrasonographic evaluation, showing a slow, constant enlargement. Three patients with benign nodules diagnosed at FNAC, were followed for 11, 9 and 7 years by annual ultrasonographic evaluation. After several years of latency, the nodules had an unexpected and gradual increase in their dimensions, reaching a large final size. A second FNAC confirmed the previous cytologic diagnosis of benign lesion. Because of the increasing size of the nodules, the patients were advised to surgery. Before undergoing thyroidectomy, we performed molecular diagnostic tests that revealed the absence of BRAF(V600E) and the presence of RET/PTC-1 in one nodule and RET/PTC-3 in the two others. Despite the presence of this oncogene, the samples were histologically classified as benign hyperplastic nodules. These findings lead us to speculate that histologically benign hyperplastic thyroid nodules containing RET rearrangements might represent a subgroup of nodules with a rapid size increase.

Expression of Vascular Endothelial Growth Factor and Presence of Angiovascular Cells in Tissues from Different Thyroid Disorders

Vascular endothelial growth factor (VEGF) is involved in tumor angiogenesis and other pathophysiological processes. We studied the localization of VEGF in human thyroid tissues to clarify its involvement in proliferative processes in a variety of thyroid disorders. Immunohistochemical analysis using purified rabbit polyclonal anti-human VEGF or anti-human CD34 antibody and a streptavidin-biotin peroxidase complex detection system was performed on 58 tissue specimens from 53 patients with different thyroid disorders and 5 normal thyroid glands. Vascular endothelial growth factor was not detected in normal thyroid follicular cells. However, some thyroid tumor cells expressed VEGF in the cytoplasm (papillary carcinoma, 10/18; follicular carcinoma, 1/3; medullary carcinoma, 2/2; follicular adenoma, 3/11; adenomatous goiter, 2/4). In benign follicular adenoma and adenomatous goiter, weak expression of VEGF was found in small areas of the tumor, whereas in malignant thyroid tumors, it was strongly expressed in many cells. However, VEGF was not expressed in anaplastic carcinoma, malignant lymphoma, or Graves' disease. Angiovascular cells stained with CD34 antibody in tissues from different thyroid disorders reflected statistically significant differences in papillary carcinoma, follicular adenoma, and Graves' disease compared with normal thyroids, and such cells showed a trend toward increases in medullary carcinoma and adenomatous goiter. In contrast, low vascularity was observed in anaplastic carcinoma, malignant lymphoma, and follicular carcinoma. Because VEGF probably functions as a hypoxia-inducible angiogenic factor, overexpression of this mediator, concomitant with hypervascularity, may be induced more strongly in malignant thyroid tumors, which need more oxygen to proliferate, than in benign follicular tumors. However, neither VEGF nor CD34 was expressed in anaplastic thyroid carcinoma, which is an extremely poorly differentiated malignant tumor. CD34 but not VEGF was expressed in the hyperplastic thyroid tissues of Graves' disease composed of nontransformed cells. Thus, the expression of VEGF concomitant with CD34 is suggested to reflect both the transformation and differentiation state of malignant tumors.

HYPERPLASTIC THYROID G1AND

Aim and Objective: The study was conducted to see the vascular and follicular changes induced by dexamethasone (syntheticcorticosteroid) during involution of hyperplastic thyroid gland in albino rats. Study Design: A comparative histological study done in PostGraduate Medical Institute Lahore in 1998 Procedure: 54 adult rats were taken and divided at random into two control groups having 27 ratsand experimental groups containing 27 rats. Control group was given normal diet along with 2 microgram of Potassium iodide intraperitonealyfor 21 days while experimental groups further subdivided into group A having 3 rats and group B and C containing 12 rats each. All theexperimental groups were treated with Thiourea for 21 days. Group A was sacrificed on day 22 after withdrawal of thiourea. Group B was givenPotassium iodide intraperitonealy after stoppage of TU on day 21 and were sacrificed on days 22,26,30 and 50 in 4 sub groups (B1-B4) tostudy the involution process. Group C was injected dexamethasone from 22 to 50 days after withdrawal of TU and sacrificed on same daysin 4 subgroups (C1-C4) as sub groups B. Results: The results of experimental group. A showed increase in thyroid and relative tissue weight.Histologically this group exhibited significant increase in stromal congestion with tall follicular cells lining the small sized follicles having scantycolloid. The results of experimental groups B and C demonstrated increase in thyroid and relative tissue weight but microscopically subgroupsB revealed early and complete involution whereas subgroups C showed significantly persistent hyperplastic changes in the form of stromalcongestion, vessels wall remained well defined and tall follicular cells lining small empty follicles. Conclusion: It was concluded thatdexamehasone did retain hyperplastic changes during involution evident by stromal congestion and small sized regular follicle lined by tallfollicular cells, so it should be carefully used in thyroid diseases.

Impact of connexin32 deletion on E7 or RET/PTC3 oncogene-driven growth and neoplastic transformation of the thyroid gland

Connexins (Cx) form gap junctions and allow direct cell-to-cell communication. Cx through gap junctions or by themselves play regulatory roles on cell growth and differentiation. Using genetically modified mice, we previously found that Cx32 acts as a down-regulator of growth in normal thyroid gland. In this study, we examined the impact of Cx32 ablation on oncogene-driven thyroid growth and neoplastic transformation. Cx32 knockout (Cx32-KO) mice were crossed with transgenic mice expressing, selectively in the thyroid gland, either the E7 or RET/PTC3 (RP3) oncogene. As already described, Cx32-KO mice had no detectable thyroid alteration in physiological conditions and mice expressing E7 or RP3 exhibited time-dependent thyroid hypertrophy and variable changes in expression of differentiation. The thyroid of E7 mice evolved towards a large colloid goitre whereas RP3 mice developed a hyperplastic thyroid of variable size, and the largest glands (about 40% of total) represented a profound tissue remodeling with proliferative papillary formations. E7-induced thyroid hypertrophy was reduced by about 40% in Cx32-KO mice as compared with wild-type (WT) littermates. On the contrary, thyroid hypertrophy induced by thyrotropin stimulation (in response to goitrogen treatment) was enhanced by about 40% in Cx32-KO mice as compared with WT mice. Thyroid hypertrophy of RP3 mice and the proportion of glands showing extensive tissue remodeling were drastically reduced in mice devoid of Cx32. Our data show that Cx32, which negatively controls thyroid growth activated by thyrotropin via the cAMP pathway, would act as a positive effector of thyroid growth triggered by oncogenes acting through other signaling cascades.

Multinodular Goiter and Primary Hyperparathyroidism: A Circuitous Route to Diagnosing Metastatic Uveal Melanoma

Uveal melanoma spreads exclusively via a hematogenous route and is notable for its latency. Liver metastases are common; however, metastatic spread to unusual sites has been encountered. We report the case of metastatic uveal melanoma in a woman with multinodular goiter and primary hyperparathyroidism. The patient presented with hypercalcemia and an elevated intact parathyroid hormone level, in conjunction with a follicular neoplasm in the setting of goiter. She underwent an uneventful total thyroidectomy and parathyroidectomy. Postoperatively, she became normocalcemic. Histopathologic analyses revealed metastatic uveal melanoma cells within both the multinodular goiter and parathyroid adenoma. At present, she is enrolled in a phase II trial for disseminated uveal melanoma. This is a report of uveal melanoma metastatic to both a parathyroid adenoma and a nodular hyperplastic thyroid. Additionally, this case serves to display the unusual metastatic potential of uveal melanoma.

Intratracheal Ectopic Thyroid Tissue with Adenomatous Hyperplasia in a Pregnant Woman

W161 resembling those of the orthotopic thyroid gland. Moreover, there was a connection between the nodule and the thyroid gland at the posterior wall of the trachea (Figs. 1B–1E). Because thyroid malignancy was suspected and because the patient elected to undergo therapeutic abortion, 131I scanning was performed after acquiring written informed consent for the study. The thyroid glands showed mild diffuse enlargement with slightly reduced radioactive iodine uptake (10.3%). However, no focal hot uptake was observed within the intratracheal nodule. An intratracheal nodule biopsy performed by rigid bronchoscopy revealed thyroid tissue with adenomatous hyperplasia. For confirmative diagnosis and treatment, segmental resection and anastomosis of the trachea were executed at the lesion site. At surgery, a relatively well-circumscribed, tan softtissue nodule was found in the lumen of the trachea (Fig. 1F). The nodule was connected to the thyroid gland at the posterior wall of the trachea. Histopathologic examination revealed variously sized hyperplastic thyroid follicles containing colloid beneath the ciliated columnar epithelium, suggestive of ectopic thyroid tissue with adenomatous hyperplasia (Fig. 1G). The orthotopic thyroid gland also showed adenomatous hyperplasia. The patient had an uneventful hospital course after surgery.

Comparison of Extended Field of View and Dual Image Ultrasound Techniques for the Measurement of the Longitudinal Dimension of Enlarged Thyroid Glands

Extended field of view (EFOV) ultrasound (US) provides images with a large anatomic field of view and is a technical modification of conventional US. In this study, we aimed to assess the role of EFOV US in the accurate measurement of the longitudinal dimension of hyperplastic thyroid glands which were too big to be documented in a single image. In addition, the accuracy and reliability of EFOV US were compared with those of dual image US. The actual longitudinal dimensions of 22 surgical specimens of thyroid glandular lobes excised by thyroidectomy were measured manually in the postoperative period. The longitudinal dimensions were also measured by two radiologists using EFOV US and dual image US after the surgical specimens were being placed in containers filled with gel. The accuracy and the reliability of EFOV US ( r = 0.997–0.999; reproducibility, 99.88%; repeatability, 99.88–99.92) were found to be higher than the dual imaging technique ( r = 0.970–0.986; reproducibility, 99.51%; repeatability, 99.56–99.59) in measuring the longitudinal dimension of enlarged thyroid glands. However, our results revealed that both US techniques can be considered in the evaluation of hyperplastic thyroid gland size. Dual image US should be regarded as the second choice for longitudinal dimension measurement of hyperplastic thyroid glands. Based on our findings, we propose the use of EFOV US for accurate and reliable measurements in patients with an enlarged thyroid gland. EFOV US has a crucial role in the diagnosis and follow-up of patients undergoing medical therapy for diffuse or nodular goiter.

Enhanced B-Raf protein expression is independent of V600E mutant status in thyroid carcinomas

BRAF (7q24) encodes a serine/threonine protein kinase, and its expression level varies in different tissues. Although a high prevalence of BRAF mutation has been suggested as an important event in thyroid tumorigenesis, little is known about the expression pattern of B-Raf in the thyroid. Thus, we examined the expression of B-Raf in various neoplastic and nonneoplastic thyroid tissues and compared it with BRAF mutational status. Normal and hyperplastic thyroid tissues showed focal and faint immunoreactivity for B-Raf, especially in cuboidal follicular cells of small follicles. In contrast, diffuse expression of B-Raf was observed in follicular adenomas and well-differentiated carcinomas. The missense point mutation BRAF(V600E) was identified in 42% (13/31 cases) of papillary carcinomas and 33% (5/15 cases) of undifferentiated carcinomas but not in normal thyroid tissues, nodular hyperplasia, follicular adenomas, or follicular carcinomas. The immunohistochemical expression of B-Raf did not correlate with BRAF mutational status. Moreover, Western blotting revealed that B-Raf expression in thyroid carcinoma cell lines was also independent of BRAF mutation. Serum or fibroblast growth factor-1 stimulation further activates ERK1/2 in heterozygous BRAF(V600E)-positive carcinoma cells as well as BRAF(V600E) mutation-negative carcinoma cells. In conclusion, heterogeneous focal expression of wild-type B-Raf in nonneoplastic tissues may play a role in the growth or functional activity of thyroid follicular cells. In contrast, diffuse expression of wild-type and/or mutant B-Raf may be involved in the tumorigenic process resulting in activation of the mitogen-activated protein kinase signaling pathway in cooperation with other genetic abnormalities and activation of ligand-receptor signaling pathways.

Peptide Products of the Neurotrophin-Inducible Gene vgf Are Produced in Human Neuroendocrine Cells from Early Development and Increase in Hyperplasia and Neoplasia

Although the neurotrophin-inducible gene vgf is expressed in mammalian neurons and endocrine cells, limited data is available in man. The objective of the study was to map proVGF peptides in human endocrine cells during development, adulthood, hyperplasia, and tumors. Antisera were generated against peptides related to internal cleavage or cleavage-amidation sites (rat proVGF(422-430) and human proVGF(298-306)-NH2) and the proVGF C-terminal ending (human proVGF(607-615)). Developing and normal adult endocrine cells, hyperplastic endocrine lesions (thyroid, parathyroid, lung, and stomach), and 120 tumors (102 endocrine) were studied. Immunogold electron microscopy was performed on normal adult pancreas and gut, and Western blotting was performed on extracts of control tissues and endocrine tumors. proVGF fragments were revealed in developing pituitary, gut, pancreas, and adrenal medulla from 10 gestational weeks, in normal adult pituitary and adrenal medulla, pancreatic glucagon, and insulin cells and gut serotonin cells, in hyperplastic thyroid calcitonin cells, lung P cells, gastric enterochromaffin-like cells, and gastrin cells, and in 88 of 102 endocrine tumors. At electron microscopy proVGF immunoreactivity was restricted to electron-dense granules. Western blotting revealed large molecular weight forms and cleavage fragments in both control tissues and tumor extracts. proVGF-related peptides are present in endocrine cells early during development and adulthood and increase in hyperplasia and tumors, and proVGF fragments could be novel diagnostic tools for endocrine cells and related lesions, including tumors.