The diagnosis of thyroid lesions using aspiration cytology was first reported by Martin and Ellis in 1930 [1]. The routine use of fine needle aspiration cytology (FNAC) in the assessment of thyroid nodules has reduced the number of patients subjected to thyroidectomy for benign diseases of the thyroid [2-4]. As a result, the incidence of malignancy at thyroidectomy has increased from 5-10% to 30-50% in the recent years [6]. This relatively simple procedure has assumed a dominant role in determining the management of patients with thyroid nodules [7,8]. However, the success of FNA is contingent upon several important contributing influences including aspirator experience [9-11], skillful cytological interpretation and a rational analysis based upon a synthesis of cytological and clinical information in the context of an individual patient [10,11]. The aim of this prospective study was to evaluate the clinical, thyroid FNAC and correlate it with histology. The advancements in management of thyroid pathology have been possible, thanks to the developments in the field of imaging. Most importantly USG in the pre operative evaluation has enhanced the armamentarium of the head and neck surgeon.

A prospective study carried out on 200 patients of solitary thyroid swelling between the age group of 11-70 yr, attending department of surgery, RLJ hospital and research centre, kolar during the period of October 2007 to December 2011. Patients with pubertal thyroid swelling, multinodular and not willing patients not included in the study.

All patients were examined clinically after taking detailed history. Then they were investigated with FNAC and USG of the thyroid. High resolution 7.3 MHz probe is used [12]. The results of FNAC were interpreted as benign, malignant, suspicious, and inadequate aspirate using a 23-gauge needle attached to a Franken's handle was used, either without or with aspiration by a 20 ml disposable syringe [13]. Two to three passes were made in each case. In the case of cystic nodules, the cysts' contents were aspirated, centrifuged, and slides made from the sediment for cytological analysis [14,15]. Sonologically the nodules were evaluated for size, location, echotexture, margins, presence halo, calcification, vascularity, accessory nodules and associated cervical nodes and consistency of (solid, cystic or mixed) [12] in order to differentiate from benign &malignant nodules. Then all the patients subjected to surgery, the HPE of the specimen were correlated with finding of FNAC and USG [14,16].

The age of the patients range from 11-70 yrs, the commonest age group with thyroid pathology is 31-40 yrs and mean age of 35.4 yrs. Majority of patients were females (69%) (M:F - 1:2.2). All the patients were presented with swelling in the neck and 28 patients had pain in the swelling. Duration of complaints ranged from 1 week to 8 yrs, majority of the patients presented between 6 months to 3 yrs. None of the patients had any significant family history. Clinical diagnosis of solitary nodule of thyroid was commonest with benign category occupies the major group with 122 (61%) followed by 58 (29%) cases and malignant 20 (10%) cases. The most common lesion in HPE is benign follicular adenoma 66 (33%) and the least being benign cyst 4 (2%).

On USG cases with benign category is major group 140 (70%) [17] cases, followed by malignant 50 (25%) of cases andsuspicious 10 (5%) cases. Out of the 200 patients diagnosed to have SNT, HPE revealed 82% benign and 18% malignant.

In 122 cytologically diagnosed benign cases [18-20], all proved to be benign, only malignant lesion found was papillary carcinoma 20 (10%) cases. All the 58 cases of follicular neoplasm were subjected to surgery and correlated with HPE, 20 cases were benign and 9 cases were malignant [21]. The USG diagnosis of benign lesion was confirmed in 132 (93.5%) [22] out of 140 cases and was disputed in 4 (6.05%) cases by histopathology which turned to be malignant. In 10 USG suspects, HPE revealed 6 benign and 4 malignant lesions. Among 50 USG diagnosis of malignant lesions, 26 were confirmed by HPE and 24 were disputed to be benign. The USG diagnosis of benign lesions was confirmed in 104 (74.25%) cases out of 140 and was suspicious in 36 cases by FNAC. out of 10 suspect cases 4 turned to be malignant. Out of 50 malignant cases 18 were proved by FNAC and 20 were suspicious. Among total 200 cases of SNT, USG revealed multiple nodules 34 (17%) cases; it is more sensitive diagnostic modality to detect nodularity.

The commonest surgery performed was hemithyroidectomy [12,23] 126 (63%) cases. Functional neck dissection was done in 26 patients of papillary carcinoma thyroid where lymph nodes palpable (Tables 1-6).

Table 1: Comparison of USG and FNAC30: BENIGN

Table 2: MALIGNANT:Sensitivity – 90%,Specificity –82%,Positive predictive value – 36%,Negative predictive value – 98.60%.

Table 3: COMPARISON OF USG WITH HPE33; BENIGN.

Table 4: MALIGNANT;sensitivity – 73%,specificity –85.30%,positive predictive value – 52%,Negative predictive value – 93.3%.

Table 5: COMPARISON OF FNAC WITH HPE32: BENIGN;

Table 6: MALIGNANT;sensitivity – 74%,specificity –100%,positive predictive value – 100%,Negative predictive value – 91%.

In the present study age of the patient ranged from 11-70 yrs with median age of 5 yrs. Age distribution of the present study is comparable to the number of males is the present study was 62 (31%) and the females were 138 (69%) with M:F ratio of 1:2.2, sex comparison was similar to Afroze et al. [24] commonest clinical presentation is the presence of swelling in front of neck and presented between 6 months to 3 yrs. Overall sensitivity in our series was 81.3%, 74%,while the specificity was 100% for both benign and malignant lesions. FNAC has certain limitations due to suspicious diagnosis. In the present series 58 (29%) of cases were found to be suspicious, of which 18 were malignant on final HPE [25], thus an overall malignant rate of 31.03% [26] for the suspicious group was found. Because of this high incidence of malignancy in suspicious lesions, surgical removal of these nodules should be strongly considered in these cases. In other studies the incidence of malignancy in STN ranges from 10-30%, in our study it's 18%.

The thyroid nodules on USG, 50 cases to be malignant, 26 cases were confirmed on HPE and remaining 24 cases were benign. In 10 cases where USG gave false negative of benign disease, but on HPE revealed papillary carcinoma. The overall sensitivity was 80.4%, 73%, while the specificity was 77.7%, 85.3% for both benign and malignant lesions on USG.

Watters et al. [27] interpreted USG has added advantage of examining whole gland but limited by the fact that no features were pathognomic for malignancy, so that it is regarded as complimentary to FNAC in the management STN [28,29] It has been a consistent observation that risk of thyroid cancer is more common with solitary nodules. Watters et al. [27] have shown that the prevalence of multinodularity in clinically STN is 20%-40%. In our series it's 17%. It has been observed that thyroid nodule to be detected by palpation; it must be 1 cm while on USG as small as 3mm can be detected [30].

The present study was undertaken to evaluate the usefulness of clinical examination, FNAC, USG of thyroid in the management of thyroid nodule and compare the efficacy of each investigation. Thyroid nodules were common in females of 31 to 40 yr age group, with commonest complaint as swelling in front of the neck. In our study sensitivity and specificity of FNAC was 74%, 100% and it helped in planning correct management. USG had 73% and 85.3%, sensitivity & specificity; hence USG along with FNAC will improve the diagnostic accuracy. Hemithyroidectomy is the minimal surgery in our study, which helped in getting HP diagnosis and in comparing the efficacy of above tests. An ideal test should have 100% Sensitivity and specificity. The closest method to ideal test is thus, FNAC which has high sensitivity and specificity. However combination of FNAC and USG will yield optimum results and avoids mismanagement.