RESUMEN
Forty seven cases of thyroidectomy specimens were selected for this study including 6 cases of anaplastic carcinoma, 9 cases of papillary carcinoma, 6 cases of follicular carcinoma, 8 cases of follicular adenoma and 18 cases of adenomatous goiter. Paraffin section from each case are stained by the one step silver colloid reaction to demonstrate the argyrophilic nucleolar organizer region associated proteins. Anaplastic thyroid carcinoma had mean AgNOR count per cell distinctly and significantly higher than other categories. Mean AgNOR counts of papillary carcinoma, follicular adenoma, follicular carcinoma and adenomatous goiter showed considerable overlap. It is concluded that AgNOR counting has limited value in the differentiation between neoplastic and non-neoplastic thyroid nodules