Cyto-Histopathological Diagnosis of the Thyroid Lesions: A Comparative Study

Abstract

Fine-needle aspiration cytology FNAC is the single most important diagnostic test for the evaluation of patients with thyroid lesions, it has been almost universally recognized as constituting the most significant advance of the past 20 years in the diagnostic evaluation of patients who present with palpable nodules of the thyroid gland. In this study, the effectiveness of fine needle aspiration cytology was evaluated through the identification of the correlation between the cytology diagnosis of thyroid fine needle aspiration cytology and the postoperative histopathological diagnosis. This is a retrospective study was performed on 80 cases underwent to both thyroid cytological and histopathological diagnosis, reports were retrieved from pathology archive of Aden Diagnostic Center/ Aden Governorate, during the period of 2012-2013. The inclusion criteria is that all patients, irrespective of sex and age; having thyroid lesion, diagnosed cytologically and confirmed histologically. Whereas the exclusion criteria: (1) Patients having history of recurrent thyroid carcinoma after lobectomy (2) patients who underwent fine needle aspiration cytology but did not undergo subsequent histopathological diagnosis (3) patients undergoing chemotherapy. Cytological study results in (85%) benign and (15%) malignant cases, while histological examination revealed (64%) benign cases and (16%) malignant cases. The most common benign lesion diagnosed by both cytologically and histologically was colloid goiter (63.7%) and (56.2%) respectively, followed by follicular adenoma, cytologically(15%) and histologically (21.25%), while Hashimotos` thyroditis was the less common lesion which is, by cytological diagnosis (6.25%) and by histological diagnosis (2.5%). The main malignant lesion was papillary carcinoma, (15%) of the cases were diagnosed cytologically and (20%) were diagnosed histologically. Fine needle aspiration cytology sensitivity was (62.5%), specificity (97%), Positive predictive value (83.3%), negative predictive value (91.1%), and accuracy (90%). Benign lesions were the most common than malignant, as diagnosed by both cytologically and histologically. The most common benign lesion diagnosed by both methods was colloid goiter, followed by follicular adenoma. The main malignant lesion was papillary carcinoma by methods of diagnosis. False negative cases represent 7.5% and false positive represent 2.5%. Statistical analysis for cytological diagnosis revealed that it was moderately sensitive, highly specific, and accurate. So it is recommended to be applied as routine preoperative investigation.