Should we apply suction during fine needle cytology of thyroid lesions? A prospective study of 200 cases

Fine needle aspiration cytology (FNAC) is a well-established first line diagnostic tool in evaluating palpable thyroid lesions. However, the technique depends on suction and thus is at times painful, sometimes traumatic and yield haemorrhagic material for cytological study. In more recent times, a modified technique called fine needle sampling without aspiration (FNS) has come into vogue which obviates the use of suction and therefore is more patient friendly.

To investigate whether fine needle sampling without aspiration (FNS) gives quantitatively and qualitatively superior cytologic material as compared to the conventional technique of fine needle aspiration (FNAC) in thyroid lesions.

It is a prospective study of 200 cases carried out in the Department of Pathology during two years period. Both techniques were executed on the same thyroid swelling / nodule in the same clinical session beginning with FNS followed by FNAC. The observation recorded by two pathologists were based on the scoring system proposed by Mair et al., Statistical analysis was done by Student's paired t-test using SPSS 13 software. Observation/Results: A total of 200 cases were studied. The non-aspiration technique yielded less diagnostically adequate but more diagnostically superior smears when compared with aspiration technique. The average score per case was 5.31 by aspiration technique and 6.35 by non-aspiration technique.

Both the techniques have their own merits and demerits and neither is absolutely superior to the other. A combination of both the technique gives better result.