1. Dr. Usha Sarma, Asstt. Professor, Dr. U. C. Dutta, Prof & Head, Pathology Deptt Gauhati Medical College FNAC of Thyroid Lesion 5 Years retrospective study with diagnostic accuracy and pitfall

2. INTRODUCTION The study was carried out in the Department of Pathology, GMCH for a period of 3 yrs since September 2008 till August 20011. Total 180 cases came for FNAC, out of which histological correlation was possible only in 60 cases(33.3%).

3. METHODS AND MATERIALS The FNA materials were collected from Pathology OPD and ENT/ Surgery wards; fixed and stained with MGG and PAP. The biopsy specimens were received in 10% formalin, routinely processed and stained with H&E stain.

4. Age Incidence in Bar diagram

5. SEX DISTRIBUTION Female : Male = 3 : 1

6. FNAC RESULTS(180 CASES) Non neoplastic Lesion (129) Colloid Goiter99 (55.0%) Hyperplastic Nodule18 (10%) Cystic lesion06 (3.3%) Thyroiditis06 (3.3%) Neoplastic Lesion ( 51) Papillary carcinoma27 (15%) Follicular neoplasm12(6.7%) Hurthle cell neoplasm06 (3.3%) Medullary carcinoma03 (1.7%) Anaplastic carcinoma03(1.7%)

7. CYTOHISTOLOGICAL CORRELATION (60cases) DiagnosisCytologyHistology Non neoplastic Colloid Goiter3332 Hyperplastic Nodule0603 Thyroiditis0203 Cystic Lesion02 Total4340 NeoplasticPapillary Carcinoma0912 Follicular neoplasm0405 Hurthle cell neoplasm0201 Medullary Carcinoma01 Anaplastic Carcinoma01 Total 17 20

8. HASHIMOTO’S THYROIDITIS Cytology Histology

9. SUBACUTE THYROIDITIS

10. FOLLICULAR ADENOMA

11. PAPILLARY CARCINOMA SCANNER HIGH POWER

12. PAPILLARY CARCINOMA

13. HURTHLE CELL NEOPLASM

14. MEDULLARY CARCINOMA

15. ANAPLASTIC CARCINOMA LOW POWER HIGH POWER

16. CYTOHISTOLOGICAL CORRELATION CYTO- LOGICAL DIAGNOSIS NO. OF CASESHISTOLOGICAL DIAGNOSIS consistentinconsistent NON- NEOPLASTIC 43394 NEOPLASTIC17161

17. DISCUSSION Out of the 60 cases, 55 cases were found to be accurately diagnosed. 5 cases were not consistent with histopathological diagnosis.

18. Cases showing cytohistological disparity NO.OF CASESCYTOLOGICAL DIAGNOSIS HISTOPATHOLO GICAL DIAGNOSIS 1Colloid goitre with cystic change/Thyroid cyst Follicular adenoma 1Hurthle cell tumour Hashimoto’s thyroiditis 3Hyperplastic Nodule Papillary carcinoma

19. DISCUSSION (CONTD.)  One case of follicular adenoma was misdiagnosed as Thyroid cyst due to aspiration of cystic content on FNA.  One case of Hashimoto’s thyroiditis was over diagnosed as Hurthe cell tumour possibly due to absence of lymphoplasmacytic cells in the smear.  Three cases of papillary carcinoma were under diagnosed as Hyperplastic nodule on cytology because of lack of representative material and absence of distinctive nuclear features in the cell aspirated.

20. SUMMARY SPECIFICITY= 97.5% SENSITIVITY= 80.0% POSITIVE PREDICTIVE VALUE= 94.1% ACCURACY= 91.7%

21. CONCLUSION Thyroid FNAC is now a well established, first line diagnostic test for any thyroid swelling with the aim of confirming benign lesion, thereby, reducing unnecessary thyroid surgery. The success of FNAC depends on many factors like: aspirator experience skillful cytological interpretation rational analysis based on cytological and clinical information in context of an individual patient.

22. Hence it is the duty of every cytopathologist to get oriented to the utility and limitation of FNAC in thyroid lesions in order to offer a cheap, reliable, quick and correct diagnosis which will help immensely in the management of thyroid lesion.

24. ACKNOWLEDGEMENT  Dr. R. A. Sangma, Prof. Pathology,GMCH.  Surgeons from Surgery & ENT deptt, GMCH  Endocrinologists of GMCH  Dr. Asitava