Comparative Study Of FNAC And HistopathologyIn The Diagnosis Of Thyroid Swelling

摘要

Objective: The aim of this study was to determine the accuracy of Fine needle aspiration cytology in detection of thyroid swellings in our ENT unit and to assess the correlation between preoperative cytodiagnosis and postoperative histopathological diagnosis.Study design: Cross sectional studyPlace & Duration of study: Department of ENT- Head & Neck Surgery, Charak hospital, Pokhara, Nepal, from January 2010 to December 2010.Method: Fifty patients with enlarged thyroid gland, of both sexes were selected. All patients had preoperative fine needle aspiration (FNAC), performed by pathologist at histopathology department and postoperative specimens were also examined after which histopathological diagnosis were made. All FNAC reports were correlated with histopathology diagnosis.Results:Out of 50 patients 46 were female and 4 male. FNAC was accurate in 94% patients. Over all sensitivity was 91.66% and specificity of 97.29%.Conclusions:FNAC is reliable, safe and accurate method as a first line of evaluation in thyroid gland nodulesbefore surgery. FNAC is more specific than sensitive in detecting thyroid gland malignancy andtherefore histopathological analysis still remains essential for the final diagnosis. Introduction Nodular goiter remains a problem of enormous magnitude all over the world. The problem in clinical practice is to distinguish reliably the few malignant tumours from the many harmless nodules so that a definitive pre-operative tissue diagnosis of malignancy allows planning of appropriate surgery and relevant patient counselling. Fine needle aspiration cytology (FNAC) is simple, less expensive, readily available and reliable, time saving, easy to perform, effective and almost accurate diagnostic technique for investigation of thyroid swelling. The prevalence of thyroid swelling ranges from 4% to10% in the general adult population and from 0.2% to 1.2% in children1. The majority of clinically diagnosed thyroid swelling are nonneoplastic; only 5%–30% are malignant and require surgical intervention2.Histological examination of the removed thyroid swelling is the most accurate way to determine the pathology. It requires preparation and long procedure like anaesthesia, hospitalization and sometime even over treatment (Thomas V, 2000).Laboratory investigations other than FNAC have limited role to find out the nature of thyroid swelling. Isotope scan can demonstrate the functioning capacity of the nodule but cannot predict the histopathological character (Satter MA,2003). Ultrasonographic scanning is capable of differentiating solid from cystic lesion but cannot distinguish malignant from benign one (Pendse A.K, 1983). The main stem of diagnosis of nodular thyroid swelling is by clinical means, fine needle aspiration cytology and histopathological (histopathology) examination. But they differ in many occasions and therefore this comparison is done with a view to make the correlation between FNAC and histopathology .Previous studies shows that the sensitivity of thyroid FNAC ranges from 80 to 98 percent and its specificity from 58 to 100% (Bajaj Y, 2006).92). Methods A Cross sectional study was done in the Department of ENT- Head & Neck Surgery, Charak hospital, Pokhara,Nepal, from January 2010 to December 2010. All patients were evaluated by thorough clinical examination followed by routine investigations, thyroid function tests, FNAC and histopathological examination. The cytology reports were compared with the histological diagnoses. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.Inclusion criteriaThose patients presenting with thyroid swelling who underwent FNAC ,thyroid surgery and histopathological examination.Exclusion criteria All the cases of thyrioditis were excluded.Those patients having FNAC done but didnot had thyroid surgery were excluded. Results