DIAGNOSTIC ACCURACY OF FNAC IN DETECTION OF THYROID CARCINOMA

Abstract

Background; Thyroid nodules are quite common and different imaging techniques are now used for diagnosis of thyroid nodules like radionucleotide scanning, high-resolution ultrasonography, etc. However, FNAC is still regarded as the single most accurate and cost-effective procedure, particularly if ultrasound is used as a guide for better sample collection, especially for cystic lesions. The current study was done to ascertain diagnostic accuracy of FNAC using histopathology as gold standard. Objective: To determine the diagnostic accuracy of FNAC in detection of thyroid carcinoma in patients with thyroid nodules using histopathology as gold standard.

Material and Methods; A total of 120 patients were taken in this study. Both genders with thyroid nodules › 2 months aged more than 18 years were enrolled in our study. Patients receiving chemotherapy or radiotherapy, confirmed cases of thyroid carcinoma and previous history of any type of thyroid surgery were excluded from our study. Sample size was 120 specimens fulfilling the inclusion criteria received at the department of histopathology, Nishtar Hospital Multan. Results; Of these 120 study cases, 28 (23.3%) were male patients while 92 (76.7%) were female patients. Mean age of our study cases was 42.31 ± 8.40 years. Of these 120 study cases 104 (86.7%) were married while 16 (13.3%) were un-married. Mean disease duration was 8.34 ± 3.91 months while 76 (63.3%) had disease duration more than 6 months and 66 (55%) had more than 10 cm size of nodule. Only 8 (6.7%) of these patients were using Iodine in their diet while remaining 93.3 % were not using Iodine supplemented diet. FNAC results revealed that thyroid carcinoma was present in 39 (32.5%) while histopathology documented thyroid carcinoma was present in 31 (25.8%) of our study cases. Sensitivity of FNAC was 87 %, specificity was 86.51 %, diagnostic accuracy was 86.66 %, positive predictive value was 69.23 % and negative predictive value was noted to be 95.06 %. Conclusion; Fine needle aspiration cytology (FNAC) is a sensitive, specific, and accurate initial diagnostic test for the evaluation of patients with thyroid swellings. It is highly reliable, easy to perform, cost-effective and accurate tool to differentiate a malignant lesion from a benign one with high accuracy.

Keywords; Thyroid nodules, thyroid carcinoma, FNAC.