Prevalence of incidental thyroid carcinoma (ITC) among total thyroidectomies performed by PSU-UOR on multinodular goiters; how accurate is the diagnosis and how rational is the treatment?

Background FNAC is regarded as a accurate, safe, and economical technique in identifying thyroid cancer in Mulitnodular goiter (MNG). The aim of our study was to detect the accuracy of FNAC in detecting thyroid cancer among patients undergoing total thyroidectomy at Professorial surgical unit, Teaching Hospital-Galle (PSU-THK).  Methods Indications for total thyroidectomy at PSU-THK include Thy 3-5 on FNAC, retrosternal goiters, those presenting with symptoms suggestive of obstruction or infiltration and cosmesis. However thy1-2 are also offered depending on the situation. Patients who had undergone total thyroidectomy for MNG with FNAC reporting Thy1-2, as well as those with Thy-3 FNAC, from 1st April 2014 to 31st march 2016 were analyzed.  Results Three hundred and forty two patients completed selection criteria for the study and 299 of them were females. Forty five point six percent belonged to the 20-39 age group and 38.89% belonged to the 39-64 age group. Two hundred ad eighty-four had Thy1-2 FNAC while 58 had Thy-3. Of the Thy 1-2 group, 212 had colloid goiter on FNAC and 54 had thyroiditis. Histology revealed malignancy in 14 female patients, 9 papillary and 4 follicular. Among the 58 patients of Thy 3, 15 had confirmed malignancy with 10 papillary and 4 follicular. The policy practiced by PSU-UOR in offering total thyroidectomy to MNGs in Thy1- 2 group is justified as the study shows them to have 4.93% risk of ITC. A similarly policy of offering total thyroidectomy to all the cases with Thy3 MNGs is recommended as the requirement of a second operation is high.  Conclusion Further research need to be carried out to identify thyroid cancer in MNGs with Thy 1-3 cytology, allowing clinicians to offer total thyroidectomy for more solid indications.