Celine Foustina Mary1, Vinoth Prabu Rathinaswamy2
Thyroid gland is unique among endocrine organs. It is the largest endocrine gland in the body and the first to develop in foetal life. Thyroid nodules are very frequent. It is estimated 4-7% adults have palpable enlargement of thyroid and 10 times more have impalpable nodules. Most of them are benign and fewer than 5% are actually malignant. A multitude of diagnostic tests like ultrasound, thyroid nuclear scan, Fine Needle Aspiration Cytology (FNAC) and many more are available to evaluate goitre. Final diagnosis requires morphological examination of lesions for which FNAC and Histopathological Examination (HPE) becomes mandatory test. FNAC is considered the gold standard in evaluation of thyroid swelling.(¹) It is a simple, cost effective, readily repeated and quick to perform procedure in the outpatient department, with excellent patient compliance. However, it is not without limitations related to specimen adequacy, sampling techniques, skill of performing the aspiration. Fine needle biopsy can be performed with or without aspiration. Advocates for the non-aspiration (Zajdela) technique believe that grasping the needle hub directly improves operator sensitivity in placing the needle tip within a small lesion. It is believed that less bleeding occurs with the non-aspiration technique, an advantage in the biopsy of more vascular tissue such as the thyroid gland.(²)
To derive conclusions on the Sensitivity, Specificity, Positive predictive value and Negative predictive value of FNCC in thyroid swelling in our hospital. To compare the two techniques in terms of diagnostic adequacy and quality of smear obtained, especially with regard to malignant smears.
All patients with thyroid swelling treated by the surgical units of Government Rajaji Hospital, Madurai either as outpatients or inpatients during the above study period were randomly divided into two groups. For one group, cytology smear was obtained by aspiration technique, and for the other group the smears were obtained by non-aspiration technique. The relevant clinical details of these patients were also obtained for the purpose of the study.
In our study, age and sex distribution was statistically analysed between the two groups and was found to be equally distributed between the two populations (p values for age and sex distribution were 0.858 and 0.488 respectively between the two populations). It was observed that the non-aspiration technique yielded more diagnostically superior specimens, as compared with FNAC. The number of unsuitable smears was also greater in aspiration samples, as compared with the non-aspiration technique. The difference was statistically significant (p=0.005). In our study, no significant difference between the performances of these two techniques was noted, with respect to making a cytological diagnosis of thyroid swellings.
Although no significant difference was seen in the efficacy and diagnostic accuracy of the two techniques in evaluation of thyroid swellings, the non-aspiration technique (FNCC) is simple, easy to perform and produces better results in the form of a better quality of the cellularity and less field obscurity by blood in both neoplastic and non-neoplastic lesions of the thyroid. It has significantly less chances of producing non-diagnostic smears. The technique is free of complications and very much comfortable to the patient.