Background & Objective : Palpable thyroid nodules are found in almost 5% of the adults. Regarding the high prevalence of this condition, recognizing and evaluating them are important for physicians. Fine Needle Aspiration (FNA) is the first easy and cost-effective way for recognizing pathologic nature of the nods. The present research was an attempt to investigate the epidemiology and evaluate the pathological findings among patients using FNA.

  Methods : This is a descriptive study conducted on all 145(113 female and 32 male) patients referring to the endocrinology clinic of Ardabil in the period between October 1999 to October 2002. The data were collected using a questionnaire, the physical examination of the patients, noting down the clinical finding, doing FNA and its report presented by a pathologist. The data were then analyzed with descriptive statistics and frequency tables using SPSS software.

  Results : Most of the patients (36.5%) were 30-40 years old. FNA of 115 patients (79.4%) was reported as benign and that of 6 patients (4.1%) was malignant, 16 patients (11%) had a doubtful FNA, and in 8 patients (5.5%) the sample was not enough. Among patients with benign FNA, 102 cases (70.6%) had nodular goiter, 8 cases (5.5%) had colloid cyst, 3 cases (2%) had follicular adenoma and 2 cases (1.3%) had thyroiditis. Among patients with malignant FNA 1 case (0.7%) had follicular carcinoma and 5 cases (3.4%) had papillary carcinoma.

  Conclusions : The results indicated that most of the malignant lesion is papillary carcinoma, which has a lower prevalence compared to similar studies. Regarding the higher prevalence of thyroid carcinoma in middle ages it seems necessary to investigate the thyroid nodules in this age- group.

Background & objectives: According to the new theory of cancer stem cells, interruption in the self-renewal pathway of tissue stem cells can cause cancerous tumors. Current work has evaluated the role of self-renewal Oct-4 gene in thyroid tumors.

Methods: In this case-control study, the expression of Oct-4 gene has comparatively assessed between cancerous specimens, marginal tissues of tumors and non-tumoral nodules of thyroid using RT-PCR technique.

Results: Statistical analysis of data by one-way ANOVA showed that Oct-4 gene is significantly expressed in thyroid papillary carcinomas in comparison with tumor margin and non-tumoral nodules (p<0.05).

Conclusion: In conclusion, the dominant expression of Oct-4 gene in thyroid tumoral cells not only demonstrates the cancer stem cell theory but also shows its role in thyroid cancer appearance that can be used in differentiating thyroid papillary carcinomas from non-tumoral nodules as well as demarcation of tumors.