Accuracy of diagnosis by Fine Needle Non Aspiration Cytology technique in head and neck swellings.Its advantages and disadvantages in comparison with Fine Needle Aspiration Cytology.

Abstract

Background and Objectives: Fine needle aspiration cytology (FNAC) is a first line investigation in the diagnosis of head and neck swellings. The negative pressure applied during aspiration leads to bloody smears, especially in vascular organs like thyroid. In 1981 fine needle non-aspiration cytology (FNNAC) was introduced. The present study was undertaken to compare FNAC and FNNAC techniques in head and neck swellings. Methods: One hundred and ninety seven head and neck swellings were sampled using both FNAC and FNNAC techniques. They were compared for the five objective parameters, amount of background blood or clots, amount of cellular material present, retention of appropriate architecture, degree of cellular degeneration and degree of cellular trauma, using Mairs point scoring system. Statistical analysis was done using Mann Whitneys test. The differences were considered significant at P0.05. Results: Blood contamination was less in FNNAC as compared to FNAC in all the cases. The difference was statistically significant in thyroid, lymphnode and salivary gland lesions. Cellular yield was more in FNNAC in thyroid and lymphnode lesions, with a significant difference being noted only in lymphnode lesions. Better retention of architecture with a statistically significant difference was seen in FNNAC smears from lymphnode and thyroid lesions. There was no significant difference between the two techniques in degree of cellular degeneration and cellular trauma. More number of FNNAC smears were diagnostically superior. The diagnostic yield in FNAC was 93.43% and in FNNAC 94.28%. Conclusion: The FNNAC technique provides adequate cellular yield in all head and neck swellings, except in cystic and fibrotic swellings where FNAC is a better technique.