Fine-Needle Aspiration Versus Non Aspiration Technique of Cytodiagnosis in Thyroid Lesions

Introduction Fine Needle aspiration cytology (FNAC) is currently practiced worldwide.Fine aspiration cytology has proven to be an effective first line diagnostic tool in evaluating palpable thyroid lesions. It allows better selection of the patients who need to undergo a surgical procedure (1). However, in most of thyroid lesions, an unsatisfactory specimen, especially mixed with blood, poses an obstacle in proper interpretation. In an attempt to overcome the problem of vascularity of thyroid gland, an alternative sampling method was developed in France (2). It avoids aspiration, utilized only the needle and relies on the pressure to suck the cells inside the needle bore. For thyroid lesions this technique was first evaluated and compared with the conventional technique of FNAC by Santos & Leiman (1988) in 50 nodular lesions (3). With the advent of new interventional radiological techniques, most areas are accessible of FNAC(4,5). In present study fine needle aspiration and non aspiration technique were compared in palpable thyroid lesions to evaluate their diagnostic accuracy and reliability. Materials and Methods The present study was conducted on 50 patients presenting with a enlarged thyroid gland. All these patients were subjected to aspiration and non-aspiration techniques. Hopper et al.(6) compared the two techniques using all lengths and diameters of biopsy needles. Fine needle aspiration was performed using the syringe and holder while non-aspiration techniques was done without syringe or holder. In this technique the needle, held between the thumb and forefinger of one hand, was inserted gently into the nodule and moved in different directions. Material entering the hub of the needle by capillary action was then expressed onto clean glass lights after attaching the syringe filled with air to it and smears were prepared in the usual manner (7). The wet smears were immediately fixed in isopropyl alcohol and latter stained by Papnicolaou and Hematoxylin & Eosin. Air dried smears were stained by May-Grunwald Giemsa. An individual slide was objectively analysed using points scoring system (8,9) to enable comparison between FNAC & NA techniques as shown in table 1. On the basis of five criteria tabulated, a cumulative score between 0-10 points was allocated to each fine needle specimen which was then categorized to one of three categories: (i)Unsuitable for cytodiagnosis (Score 0-2);(ii) Suitable for cytodiagnosis(Score 3Abstract The two sampling techniques were studied in 50 patients presenting with enlargement of thyroid gland. They were sampled by fine needle aspiration (FNA) and by non-aspiration (NA a needle without application of aspiration pressure). Cell samples were cytologically assessed and were scored (0, 1 & 2) using five objective parameters which includes background blood or clot, amount of cellular material, degree of cellular degeneration, degree of cellular trauma and retention of appropriate architecture. Non-aspiration performed better than FNAC for criteria background blood or clot and retention of appropriate architecture with statistically significant difference. Non-aspiration also scored better than FNAC for the other parameters as well as cumulatively. Smears were then cytologically assessed as diagnostically inadequate, adequate and superior. Greater number of diagnostically adequate specimens were obtained by FNAC than by NA but the number of diagnostically superior specimen were obtained significantly more frequently by the non-aspiration technique. Thus, the non-aspiration technique combined with FNAC can result in obtaining good quality cellular material in thyroid lesions.