[Value of the intraoperative pathology in thyroid surgery. Comparison with preoperative aspiration puncture and deferred pathology].

To evaluate the usefulness of intraoperative pathology (IP) in thyroid surgery, a retrospective review of its results in 350 patients was performed in comparison with the results of the preoperative fine-needle biopsy (FNB) and the surgical pathology report (SPR). The FNB was reported according to the Bethesda system as type II in 91 cases (26.0%), type III in 21 (6.0%), type IV in 73 (21.9%), type V in 54 (15.4%), and type VI in 111 (31.7%). The IP showed benign lesions in 137 cases (39.1%), malignancy in 169 (48.2%), and inconclusive results in 44 (12.6%). The SPR results were benign pathology in 161 cases (46%) and carcinoma in 189 (54%); carcinoma was found in 8 patients (5.8%) in whom the IP had reported benignity, and in 12 (27.2%) with IP inconclusive results; 13 of those 20 cases were incidental microcarcinomas. The IP did not report any false positive result (specificity 100 %, sensitivity 89.4%, positive predictive value 100%, negative predictive value 90.0%, and accuracy 94.2%). When discriminated by Bethesda types, the malignant lesions detected by IP and SPR were, respectively: II 3 (3.3%) and 7 (7.70%); III 8 (38.1%) and 10 (47.6%); IV 3 (4.1%) and 10 (13.7%); V 47 (87.0%) and 52 (96.3%); VI 108 (97.3%) and 110 (99.1%). In most cases, the IP did not provide additional information to the FNB report nor did it detect microcarcinomas in others, so it does not seem justified to perform it routinely.