[Thin layer preparations in thyroid fine-needle aspiration: study of 200 cases]

Trying to increase the specificity and demonstrated sensibility of thyroid fine needle aspiration (TFNA) in the diagnosis of the thyroid nodule, and to improve the cytomorphologic diagnosis, we used the approach of realization of thin prep (TP), adapting the technique to the methods within our possibilities.

The sample corresponded to a prospective study of 200 cases of material of thyroid nodules, obtained by means of ultrasonography guide fine needle aspiration, over a 30 month period. The study was carried out by means of conventional smear (CS) and TP, cytologic preparations were stained with hematoxilin-eosine (H-E), Papanicolaou (PAP) and Tint 15. The analysis of these same samples was carried out according to sex, age, characteristics of the nodules and cytomorphologic features.

The samples were satisfactory in 184 cases (92%) and unsatisfactory in 16 cases (8%). The prevalence in samples corresponded to the female sex (88.5%). The pre-emptive diagnoses corresponded to: Multinodular Goiter: 41 (22.29%)--Hashimoto's thyroiditis: 4 (2.17%)--Follicular lesions I: 86(46.74%), II: 34 (18.47%), III: 6 (3.26%)--Hürthle cell neoplasm: 4 (2.17%)--Papillary carcinoma: 9 (4.90%). The patient study was carried out according to the modified algorithm proposed by Gharib in 1997 and the Department of Cytology of the Karolinska Hospital of Stockholm (Sweden). The cytological diagnosis was compared to the final histological results.

The present work has demonstrated that even with the available methods, we have been able to carry out TP that were acceptable for its evaluation and with the same limitations of those obtained by CS, with respect to preparations dried in direct air and in the cases of non-conclusive diagnoses. We obtained a sensibility of 94.44% and a specificity of 98.79%.