Malignancy risk analysis in patients with inadequate fine needle aspiration cytology (FNAC) of the thyroid

Background Thyroid fine needle aspiration cytology (FNAC) is the standard diagnostic modality for thyroid nodules. However, it has limitations among which is the incidence of non-diagnostic results (Thy1). Management of cases with repeatedly non-diagnostic FNAC ranges from simple observation to surgical intervention. We aim to evaluate the incidence of malignancy in non-diagnostic FNAC, and the success rate of repeated FNAC. We also aim to evaluate risk factors for malignancy in patients with non-diagnostic FNAC. Materials and Methods Retrospective analyses of consecutive cases with thyroid non diagnostic FNAC results were included. Results Out of total 1657 thyroid FNAC done during the study period, there were 264 (15.9%) non-diagnostic FNAC on the first attempt. On repeating those, the rate of a non-diagnostic result on second FNAC was 61.8% and on third FNAC was 47.2%. The overall malignancy rate in Thy1 FNAC was 4.5% (42% papillary, 42% follicular and 8% anaplastic), and the yield of malignancy decreased considerably with successive non-diagnostic FNAC. Ultrasound guidance by an experienced head neck radiologist produced the lowest non-diagnostic rate (38%) on repetition compared to US guidance by a generalist radiologist (65%) and by non US guidance (90%). Conclusions There is a low risk of malignancy in patients with a non-diagnostic FNAC result, commensurate to the risk of any nodule. The yield of malignancy decreased considerably with successive non-diagnostic FNAC

Effects of octreotide on propylotiouracil-induced goiter in rats: a quantitative evaluation

To evaluate the possible antigoitrogenic effect of somatostatin, the influence of long-acting somatostatin analog - octreotide - on experimental goiter developed in rats treated with propylthiouracil was examined. Goiter formation was assessed by measurement of the main histological compartments of the thyroid as well as by morphometric analysis of the vascularization and blood supply of the gland. Although treatment with octreotide did not prevent the goiter formation, it clearly reduced blood supply and vascularization of the thyroid and counteracted propylthiouracil- induced increase in the relative volume of follicular epithelium. To conclude, the somatostatin analog - octreotide - is effective in reduction of goiter vascularisation. This finding provides a rationale for the clinical trials of the treatment of hypewascular goiter by somatostatin analogs

Effects of octreotide on propylotiouracil-induced goiter in rats: a quantitative evaluation

To evaluate the possible antigoitrogenic effect of somatostatin, the influence of long-acting somatostatin analog - octreotide - on experimental goiter developed in rats treated with propylthiouracil was examined. Goiter formation was assessed by measurement of the main histological compartments of the thyroid as well as by morphometric analysis of the vascularization and blood supply of the gland. Although treatment with octreotide did not prevent the goiter formation, it clearly reduced blood supply and vascularization of the thyroid and counteracted propylthiouracil- induced increase in the relative volume of follicular epithelium. To conclude, the somatostatin analog - octreotide - is effective in reduction of goiter vascularisation. This finding provides a rationale for the clinical trials of the treatment of hypewascular goiter by somatostatin analogs

Multiparameter analysis of AgNOR in thyroid lesions: comparison with PCNA expression

The aim of the study was to examine numerous features of argyrophilic proteins related to nucleolar organizer regions (AgNORs) in thyroid tumors, relate them to PCNA expression and evaluate which of these features might be useful in the diagnosis of thyroid lesions. Paraffin sections of 100 thyroid tumors were silver-stained and divided into 9 groups: nodular goiter (NG), simple adenoma (SA), microfollicular adenoma (MFA), follicular carcinoma (FC), follicular variant of papillary carcinoma (PC-F), classical variant of papillary carcinoma (PC-C), Hürthle cell adenoma (HA), Hürthle cell carcinoma (HC), and anaplastic carcinoma (AC). The slides were analyzed with the computerized system for image analysis. A weak correlation was found between PCNA expression and AgNOR size. AC differed significantly from all other examined groups in many features of AgNOR dots. Hürthle cell neoplasms were characterized by the presence of a usually single and relatively large dot. With respect to diagnosing follicular lesions, we found that the evaluation of the total area of dots in the nucleus seemed to be the most useful for discrimination: the assumption of 4.9 µm2, as a cut-off value, allowed a correct classification of 77% of FC cases. Computeraided morphometric analysis of AgNORs may be useful in the diagnostics of thyroid lesions