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At least 127 records · Page 7Linked to original sources
PubMed2003

Expression of inducible nitric oxide synthase in thyroid neoplasms: immunohistochemical and molecular analysis.

To understand the role of inducible nitric oxide synthase (iNOS) in thyroid tumorigenesis, immunohistochemical staining of 36 surgical specimens of thyroid neoplasm that consisted of seven follicular adenomas, 12 papillary carcinomas, seven follicular carcinomas, five medullary carcinomas, and five anaplastic carcinomas were analyzed. In addition, 20 specimens of normal thyroid were used as control samples. Reverse transcription-polymerase chain reaction and western blot analysis were also performed using a normal thyroid and a representative papillary carcinoma case. The intensity and proportion of the immunostained tumor cells were graded semiquantitatively. The grades of the intensity and the proportion were then summed to provide an immunohistochemical score. There was a variation in the staining intensity and proportion. The iNOS expression was low in normal follicular epithelia. Inducible nitric oxide synthase is present in the majority of thyroid tumor cells, including follicular adenomas, papillary carcinomas, follicular carcinomas, medullary carcinomas, and anaplastic carcinomas. Relatively low expression was shown in follicular neoplasms. Only a few inflammatory cells in the stroma were immunoreactive. These results suggest that iNOS may have a role in tumorigenesis, and iNOS in human thyroid carcinoma is mostly derived from tumor cells not from macrophages.

Adenocarcinoma, Follicular↗
PubMed1994

Molecular genetics of human thyroid neoplasms.

Cancers are thought to develop as a result of sequential mutations of genes important in the control of cellular growth. Recently investigators identified a number of genetic defects that affect oncogenes and tumor-suppressor genes and that provide insight into the biology of benign and malignant thyroid neoplasms. Future implications for thyroid tumor diagnosis and prognosis are considered in this chapter.

DNA, Neoplasm↗
PubMed2003

Cyclooxygenase-2 expression in thyroid neoplasms.

AIMS: Previous studies have demonstrated that cyclooxygenase-2 (COX-2) plays a role in carcinogenesis and carcinoma development. In this study, we investigated its expression in thyroid neoplasms in order to elucidate its role. METHODS AND RESULTS: COX-2 expression was studied immunohistochemically in 20 anaplastic (undifferentiated) carcinomas, 49 papillary carcinomas, 22 follicular carcinomas and 15 follicular adenomas. Positive staining was only occasionally seen in normal follicles or stromal cells. COX-2 over-expression was found in only 20.0% of follicular adenomas and 40.9% of follicular carcinomas. In papillary carcinomas, the incidence (81.3%) was significantly higher (P < 0.0001) than in follicular carcinomas, although COX-2 expression was reduced in cases with old age (P = 0.0190), large size (P = 0.0028), advanced stage (P = 0.0225), satellite tumours (P = 0.0363), and the presence of solid, scirrhous or trabecular growth patterns (P = 0.0018). Undifferentiated carcinomas less frequently over-expressed COX-2 (P = 0.0004), with an incidence of 40.0%. CONCLUSIONS: These results indicate that the up-regulation of COX-2 may contribute predominantly in the early phase of papillary carcinoma progression, whereas it plays a more adjuvant role in follicular carcinoma progression.

Carcinoma↗
PubMed2026

Fibrotubular Tumors of the Thyroid: An Emerging Thyroid Neoplasm Characterized by Distinctive Morphology and Recurrent OCLN::PRKCI Gene Fusions Spanning the Adenoma-Carcinoma Spectrum.

The histopathologic and genomic landscape of thyroid tumors is well characterized, although new genetic alterations and tumor types are being described. We present 2 cases of thyroid tumors originating from follicular cells that had highly unusual and distinct morphologic features and carried an OCLN::PRKCI gene fusion. These tumors were well circumscribed, encapsulated, and composed of irregularly shaped tubular and follicular structures surrounded by layers of distinct fibrocollagenous basement membrane material positive for type IV collagen and laminin; they showed no definitive nuclear features of papillary carcinoma. Importantly, whereas one of the tumors had no invasive growth, the other demonstrated tumor capsule invasion, compatible with the adenoma-carcinoma spectrum seen in thyroid follicular and oncocytic tumors. Gene expression profiles of these tumors differed from those of common types of papillary thyroid carcinoma. The unusual and reproducible histopathologic characteristics and unique molecular profiles of these tumors support their designation as a distinct type of thyroid neoplasm that exists in noninvasive and invasive forms and, therefore, can be designated as fibrotubular adenoma and carcinoma. Recognition of this distinct entity is important for improving diagnostic accuracy and avoiding overtreatment of this likely indolent type of thyroid neoplasia.

Humans↗
PubMed1989

[Tumor markers in the early diagnosis of thyroid neoplasms].

Radioimmunological techniques were used to assay tumour markers in order to identify neoplasms in patients with thyroid nodules at the earliest possible stage. In the 7 patients with differentiated thyroid tumours, the marker findings were within normal limits. On the basis of these results it is concluded that at the present time these markers are of no value for the early diagnosis of thyroid tumours.

Adolescent↗
PubMed1998

Blood group antigens in differentiated thyroid neoplasms.

Alteration of cell-surface blood group antigens during malignant transformation is a well-known phenomenon that has not yet been sufficiently investigated in thyroid gland neoplasms. We evaluated 50 normal thyroid glands and 141 differentiated thyroid neoplasms (29 follicular adenomas, 30 follicular carcinomas, 56 papillary carcinomas, and 26 medullary carcinomas) both by the immunoperoxidase technique, using monoclonal antibodies against blood group antigens (A, B, H, Le(a), Le(b), Le(x), and Le(y)) and precursor substances (T, Tn, and sTn), and by affinity to the lectin from Arachis hypogea, to determine the usefulness of these antigens as tumor markers and prognostic factors. Neoplastic tissues showed immunostaining with concordant and nonconcordant expression of ABH antigens. There were statistically significant differences between normal and neoplastic tissues but not among the different neoplasms. Statistically significant differences in Lewis antigen expression were noted between normal and neoplastic tissues and between benign and malignant tumors. Tn and sTn antigen expression showed statistically significant differences between normal and neoplastic tissues. In conclusion, blood group antigens are tumor markers that are expressed more frequently in malignant than in benign neoplasms. The presence of metastases was correlated with enhanced peanut lectin receptors and a loss of A or B antigens.

ABO Blood-Group System↗
PubMed1997

Follicular and Hürthle cell thyroid neoplasms. Is frozen-section evaluation worthwhile?

OBJECTIVES: To determine whether (1) frozen-section (FS) evaluation of follicular and Hürthle cell thyroid neoplasms (FHCNs) is accurate, (2) FS aids in intraoperative decision-making, and (3) FS is cost-effective. DESIGN: Retrospective review of patient histories and FS and paraffin-embedded slides. Permanent histologic sections were considered the standard criterion. Follow-up was achieved in 92% of patients with a mean follow-up of 5.7 years. SETTING: Tertiary care referral center. PATIENTS: All patients undergoing thyroidectomy for a suspected FHCN between January 1, 1985, and December 31, 1994. Patients included were those whose condition was diagnosed as FHCN, either on FS, permanent histologic sections, or both. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FS analysts were determined. Total adjusted hospital charges were compared for those undergoing 1 vs 2 cancer operations. Multivariate analyses were carried out to determine the optimal predictive model for follicular cancer. RESULTS: The study group included 1023 patients (737 women and 286 men), of whom 83 (8.1%) were diagnosed as having a malignant FHCN on permanent section. The diagnosis of malignant neoplasm was correctly established in 65 (78%) of the 83 patients on FS, thereby permitting definitive surgical management at the first operation. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for FS diagnosis of malignant FHCN were 78%, 99%, 90%, 98%, and 98%, respectively. In a multivariate analysis, FS was the most significant variable predictive of malignant neoplasm. Approximately $400,000 was saved in hospital charges by the use of FS as a result of the elimination of many 2-stage operations. CONCLUSION: Frozen-section evaluation of FHCN can be performed with a high degree of accuracy, permitting considerable cost savings.

Adenocarcinoma↗
PubMedDate not supplied

Immunohistochemical analysis of the ras oncogene protein product in human thyroid neoplasms.

The monoclonal antibody Y13 259 to the ras oncogene p21 product was used in an immunohistochemical study of ras expression in human thyroid neoplasms. Both papillary and follicular carcinomas showed consistently higher staining intensity than normal tissue adjacent to carcinomas. Some follicular, foetal, embryonal and oxyphil adenomas exhibited higher staining intensity than normal tissue. Our results suggest that elevated ras expression may be important in the development of some adenomas and in their conversion to carcinomas.

Adenocarcinoma↗
PubMed1979

Scintigraphic and clinical evaluation of nontoxic thyroid neoplasms.

256 patients were referred to the endocrinic clinic because of enlarged thyroid gland. All of them except one were subjected to thyroid scintigraphy (TS). The scintiscans were cold in 123 patients. The cold scintiscans were distributed evenly on the various referral diagnoses with half the patients of each group having cold TS. A total of 216 of the referred patients underwent surgery, among them the 123 with cold TS. If the solitary adenomas are left out of account, there was poor agreement between referral diagnosis, primary tentative hospital diagnosis, and surgical findings. Five patients were found to have thyroid cancer (TC), none of whom had been referred with this diagnosis. For the entire material the incidence of TC was 2.3% (95% confidence limits: 0.8--5.7%). Calculated on the basis of those patients who had cold TS, the incidence was 2.4% (95% confidence limits: 0.8--7.1%). It is concluded that the diagnosis of TC is difficult to establish preoperatively, and that TS is of no greater diagnostic value in this connection.

Adenoma↗
PubMed2002

Expression of G2-M modulators in thyroid neoplasms: correlation of cyclin A, B1 and cdc2 with differentiation.

Previous studies have demonstrated that cell proliferating activity accurately reflects the biological aggressiveness of thyroid neoplasms. In this study, we focused on the G2-M boundary regulators of the cell cycle and investigated the expression of three proteins, cyclin A, cyclin B1 and cdc2. The incidence of cyclin A overexpression was significantly linked to carcinoma differentiation (p < 0.0001) and, in particular, all 21 cases of undifferentiated carcinoma overexpressed this protein. On the other hand, cyclin B1 was overexpressed in four undifferentiated carcinomas (19.0%), but not in carcinomas of other types. Cdc2 overexpression was also related to carcinoma differentiation (p < 0.0001), and was directly linked to cyclin A overexpression (p < 0.0001), but not to cyclin B1 overexpression. No significant relationship could be established between the overexpression of these proteins and the histological type of follicular tumor. These results suggest that cyclin A, rather than cyclin B1, contributes significantly to the aggressive character of thyroid carcinoma, together with cdc2.

Adenoma↗
PubMed1992

Ret oncogene activation in human thyroid neoplasms is restricted to the papillary cancer subtype.

We have recently reported the activation of a new oncogene in human papillary thyroid carcinomas. This oncogene, papillary thyroid carcinoma (PTC), is a novel rearranged version of the ret tyrosine-kinase protooncogene. Thyroid neoplasms include a broad spectrum of malignant tumors, ranging from well-differentiated tumors to undifferentiated anaplastic carcinomas. To determine the frequency of ret oncogene activation, we analyzed 286 cases of human thyroid tumors of diverse histologic types. We found the presence of an activated form of the ret oncogene in 33 (19%) of 177 papillary carcinomas. By contrast, none of the other 109 thyroid tumors, which included 37 follicular, 15 anaplastic, and 18 medullary carcinomas, and 34 benign lesions, showed ret activation.

Base Sequence↗
PubMed2003

Expression and cellular localization of p8 protein in thyroid neoplasms.

OBJECTIVES: p8 protein has mitogenic activity and is linked to the development of pancreatic carcinoma. However, little is known about the expression and physiological significance of this protein in other human carcinomas. METHODS: In this study, we immunohistochemically investigated p8 expression in thyroid neoplasms as well as in the normal thyroid gland. RESULTS: p8 was expressed in normal follicular cells, but no normal thyroid was regarded as overexpressing p8. On the other hand, 44.3% of papillary carcinoma overexpressed p8 and the incidence was directly linked to the tumor size (p=0.0340) and lymph node metastasis (p=0.0145). In follicular tumors, the incidence of p8 overexpression did not depend on histological type. In anaplastic (undifferentiated) carcinoma, p8 was overexpressed only in 5.0%, which was significantly lower than in papillary (p=0.0006) and follicular carcinomas (p=0.0049). In normal follicules and follicular tumors, p8 was localized mainly in the nucleus except for two adenomas. On the other hand, p8 localization was more cytoplasmic in papillary carcinoma larger than 1.0 cm (p=0.0186) and with a poorly differentiated lesion (p=0.0313). CONCLUSIONS: These results suggest that the overexpression and cytoplasmic localization of p8 protein may reflect disease progression of papillary carcinoma, whereas this protein plays little part in thyroid carcinoma after anaplastic transformation.

Adenocarcinoma, Follicular↗