Significance of Cell Pattern Approach in Fine Needle Aspiration Cytology of Thyroid Lesions.

AIMS: To study the application of cell pattern analysis in the interpretation of thyroid lesions and to evaluate diagnostic accuracy of thyroid FNAC. MATERIALS & METHODS: A prospective study of 175 cases of thyroid FNAC were studied over a period of 2 years (May 2012- April 2014) in department of pathology of tertiary care hospital, Navi Mumbai. Two cases with inadequate aspirate were excluded from this study. The predominant cell pattern such as normofollicular/macrofollicular, microfollicular, cystic, syncytial, papillary and dispersed were noted in each case. The final diagnosis was given by viewing the cell pattern, cellular features and the background elements. The FNAC results were correlated with histological diagnosis in 50 cases. The sensitivity and specificity were evaluated. RESULTS: The normo/macrofollicular pattern was seen in 61.06% of nodular goitre and 7.69% of follicular neoplasm. Microfollicular pattern was predominantly seen in 76.92% of follicular neoplasm and 40% of papillary carcinoma. Syncytial pattern was seen in 40% of papillary carcinoma and 38.88% of Hashimoto’s thyroiditis. Papillary pattern was seen in 20% cases of papillary carcinoma and cystic pattern was seen in 27.48% of nodular goitre . The diagnostic accuracy, sensitivity and specificity was 92%, 66.66%, 100% respectively. CONCLUSION: FNAC is a simple, sensitive, cost effective and diagnostic technique for evaluation of thyroid lesions. The combined approach of cell morphology, background details along with predominant cell pattern will be helpful in diagnosing thyroid lesions on FNAC and hence increasing diagnostic accuracy.