[Evaluation of retinoblastoma expression in benign and malignant thyroid neoplasms]

Several factors are involved in the thyroid tumourigenic process. The role of Retinoblastoma [Rb] tumor suppressor gene mutation in thyroid carcinogenesis has been discussed. In this study we investigated the expression of Retinoblastoma gene in thyroid neoplasms and its association with clinical and histological findings, to evaluate its ability in distinguishing benign and malignant thyroid neoplasms and as a prognostic factor. The present cross sectional study investigated Avidin - Biotin immunohistochemistry using the Dako Rb - 1 clone in a series of 200 formalin - fixed, paraffin - embedded thyroid lesions, including 39 benign and 161 malignant neoplasms. Nuclear immunoreactivity in more than 10% of tumor cells was assessed as positive. Rb was positive in 74.2% of follicular adenoma, 87.5% of hurthle cell adenoma, 46.2% of papillary carcinoma, 66.7% of follicular carcinoma, 29.4% of medullary carcinoma and 50% of anaplastic carcinoma. Overall Rb nuclear immunoreactivity was observed in 76.9% of benign tumors and 45.9% of malignant lesions. No significant difference in Rb expression between follicular adenoma and follicular carcinoma was seen; also no association was found between Rb expression and invasiveness in malignant tumors. The results of this study indicate that Rb gene expression in benign thyroid tumors is significantly higher than in malignant ones [P=0.001], an association observed particularly in women. Rb gene inactivation is likely to play a role in malignant evolution of thyroid neoplasms and considering female predominance in thyroid tumors, Rb immunohistochemistry can potentially aid in the distinction between benign and malignant thyroid tumors in conjunction with morphology, but it is not helpful in differentiation between follicular adenoma and follicular carcinoma

[Expression of Nm23 marker in benign and malignant thyroid neoplasms immunohistochemical]

Several prognostic factors affect the outcome of thyroid carcinomas including tumor stage and distant metastases. Nm23 is a metastasis suppressor gene and has a crucial role in the control of metastatic potential of several carcinomas. The aim of our study is to evaluate expression of nm23 marker in benign and malignant thyroid neoplasms using the immunohistochemistry method and to elucidate its relationship with tumor size, vascular or capsular invasion and lymph node involvement. In a descriptive study, 200 paraffin blocks comprising of 38 benign and 162 malignant thyroid neoplasms stained with nm23 marker were studied. Cytoplasmic staining in more than 10% of cells was considered as positive. The relationship between nm23 and tumor size, vascular or capsular invasion, lymph node involvement was analysed using SPSS 11.5 software [p=0.05]. There was 40% positive incidence of nm23 in follicular adenoma, 87.5% in hurthle cell adenoma, 67.2% in papillary carcinoma, 66.7% in follicular carcinoma, and 64.7% in medullary carcinoma. In follicular adenoma, frequency of nm23 positive tumors was directly correlated to tumor size [p=0.04]. There are no statistically significant correlation between nm23 and tumor size, vascular or capsular invasion or lymph node involvement in malignant thyroid neoplasms. In papillary and medullary carcinoma, negative predictive value of nm23 for lymphnode involvement was over 80%. Also in follicular carcinoma, sensitivity and negative predictive value of nm23 for vascular invasion were approximately 90%. Lack of significant correlation between nm23 and tumor invasiveness [and probably metastasis] factors, demonstrate that although nm23 is a potentially metastasis suppressor gene, whereas in many other tumors it may play a different role in thyroid neoplasms, a role which necessitates further studies to be conducted

[Prevalence of Cox2 marker in benign and malignant thyroid neoplasms with immunohistochemistry method]

There are different prognostic factors in thyroid neoplasms. Cox2 is an enzyme which plays a role in the synthesis of prostaglandin. Increased expression of Cox2 has been reported in different kinds of cancers such as colorectal, stomach, lung, prostate, breast and thyroid. Thyroid malignancies are among the common malignancies of the endocrine system, and various molecular studies are being performed to determine their pathogenesis. To study the prevalence of Cox2 in malignant and benign neoplasms of the thyroid and its relationship with other clinical and pathological factors, we analyzed 200 paraffin blocks including 137 thyroid papillary carcinoma, 10 thyroid follicular carcinoma, 17 thyroid medullary carcinoma, 2 anaplastic cases, 27 thyroid follicular adenoma, 7 thyroid Hurthle cell adenoma using the immiunohistochemistry method for the Cox2 enzyme marker. Positive results obtained for cases Cox2 were 38.7% thyroid papillary carcinoma, 20% follicular carcinoma, 29.6% medullary carcinoma, 25.9% follicular adenoma, 28.5% hurthle cell adenoma. Statistical analysis showed no significant difference among various groups of thyroid neoplasms and expression of Cox2. Also, no relationship between vascular, lymphatic and capsule invasion and expression of Cox2 in malignant and benign neoplasms of the thyroid was found. It appears that Cox2 is not a suitable marker to distinguish between different types of thyroid neoplasm

relationship between survivin expression in thyroid follicular adenoma and carcinoma

Survivin is one of the eight members of the human inhibitors of apoptosis [IAP], which appears to be differentially expressed in cancer cells. This study was conducted to evaluate the clinical usefulness of survivin immunostaining to distinguish between follicular adenoma and carcinoma of thyroid. This study was a cross-sectional descriptive-analytical research. The study population was tissue samples from surgery patients at Shariati Hospital in Tehran, Iran. All samples were studied through immunohistochemical staining for survivin. Survivin expression was significantly [p<0.005] higher in patients with follicular carcinoma diagnosis than those with adenoma. Odds ratio of follicular carcinoma for survivin expression was reported to be 21.375 [95% CI: 3.283-139.177]. The study indicated that survivin can play an effective role in distinguishing follicular thyroid adenoma from follicular thyroid carcinoma

Frequency of hypothyroidism and factors affecting it in HIV-infected patients in Tehran, Iran [2004]

A wide spectrum of endocrine abnormalities including thyroid dysfunction has been observed in HIV-infected patients with different results. This study was conducted to determine the frequency of thyroid dysfunction and to identify factors affecting the development of hypothyroidism in HIV-infected patients. Free T4, FT3, TSH, and thyroglobulin levels of 88 HIV-infected patients receiving care at UT counseling center for Behavioral Disorders in Tehran, an out patient referral center, were measured and data on their age, sex, body weight, BMI, history of opium and injection addictions, duration of HIV infection, disease stage, history of opportunistic infection or malignancy, CD4 cell count, antiretroviral treatment with antiretroviral drugs [HAART], receipt of other drugs [TMP-SMX, antituberculosis drugs, and steroids], and hepatitis C virus Co-infection were collected. Inclusion of the subjects was simply random. 17% of subjects had hypothyroidism; 1.1% had overt hypothyroidism; 2.3% subclinical hypothyroidism and 13.6% had low FT4 levels. The multivariate analysis showed that none of the studied factors were associated with the development of hypothyroidism. As none of the above-mentioned factors are not associated with the development of hypothyroidism, hypothyroidism should be considered in HIV-infected patients

Diagnosis of pendred syndrome: MRI versus other traditional criteria

Background and purpose: Pendred syndrome, defined traditionally as the constellation of goiter, sensori-neural hearing loss and positive perchlorate discharge test. Since the relatively newer approaches to the diagnosis of this syndrome, as MRI and genetic and/or molecular analysis are much more expensive and complicated than the traditional approaches, we planned to study the value and reliability of MRI as the sole, or adjunctive diagnostic approach to the syndrome

Materials and methods: We presumed the classic triad is still the most widely accepted gold standard, and compared MRI findings in six such defined patients with six seemingly incomplete forms with goiter and hearing loss, but with negative Perchlorate discharge test

Results: There were a sensitivity and specificity of 83.3% and 66.7%, respectively for MRI in patients fulfilling all three criteria and 66.7% and 100% for sensitivity and specificity in the group lacking perchlorate test positivity

Conclusion: Although MRI can not replace the holistic approach, In [partial] cases with equivocal findings, and in the evaluation of relatives of the patients MRI may be considered as a valuable diagnostic adjunct

Evalution of the relationship between vitamin d receptor gene polymorphism [FOK I] and thyroid cancer

Background and purpose: Vitamin D is an antiproliferative agent against cancer cells and regulates cell differentiation. It acts via Vitamin D Receptor [VDR]. The VDR gene contains a Start Colon Polymorphism [SCP] that can be detected with the restriction enzyme Fok I. Previous studies report an association of SCP and some diseases and some suggest that this polymorphism alters VDR function. As no studies so far have reported the association between Fok I genotype in Thyroid cancer, this study is intended to determine the association of Fok I polymorphism of VDR with thyroid cancer risks in Iranian population

Methods and Materials: 58 patients with papillary carcinoma, 13 patients with follicular carcinoma and 82 controls participated in a case-control study. A PCR-RFLP method used to determine VDR gene polymorphism in start codon characterized by the restriction enzyme Fok I. 95% confidence intervals and odds ratio were calculated for testing the relationship between Fok I polymorphism and thyroid cancer

Results: The odds ratio for the Fok I polymorphism on thyroid cancer was 0.39 [95% CI, 0.12-1.27] witch signifies no relationship between this polymorphism and the ris of thyroid cancer

Conclusion: As no relationship was found between this polymorphism and thyroid cancer, other genetic or environmental factors may be considered in thyroid cancer