A prospective work aimed to study the spectrum of cytological features of thyroid lesions in patients with thyroid swellings and to correlate the histological appearances where ever tissues were available in patients, who attended the Govt General Hospital, Vijayawada

This study was conducted in the department of Pathology ,on patients with thyroid swellings who attended the Medical, Surgical & ENT OPs Rajiv Gandhi Institute of Medical sciences, a south Indian tertiary care teaching Government hospital Kadapa during the period of July 2015 to November 2017. A total number of 375 aspirations were performed on patients with thyroid swellings, both male and female, who attended Medical, Surgical & ENT OPs during the above period. Smears prepared were stained with H&E. Among the 375 cases aspirated material obtained was sufficient for diagnosis in 330 cases. Remaining 45 cases showed only blood cellular elements and occasional thyroid acinar cells. Before proceeding to FNAC full clinical examination of the patient was done and data like present, past and personal history of the patient along with laboratory investigations including thyroid profile and ultrasound reports were collected. FNAC was done as an outpatient procedure. A 23-24 gauge needle was used for aspiration. No local anesthetic was used. Spirit swab, 10ml disposable syringe with 23-24 gauge needles, sclean glass slides, Fixative [methanol] used for aspiration procedure. The contents were expelled on to the labelled slides and smears were prepared. The slides were placed in the fixative for 20 minutes and stained. The numbers of aspirations made were 2-4 in each case. In a diffusely enlarged thyroid both the lobes were aspirated. In a Nodular goiter multiple aspirations were made. The stain used in the present study was H&E. According to Hamberger et al in the assessment of a dominant nodule 6 clusters of benign cells in at least 2 slides prepared from separate aspirates constitute a reasonable minimum material for diagnosing benign lesions. For the present study criteria of Hamberger and Orell were taken into consideration in case of dominant nodule and colloid goiter .For the diagnosis of inflammatory and malignant lesions , type of inflammatory cells along with the back ground and cellular features were taken into consideration ,irrespective of the amount of cellularity. Basing on the above criteria the lesions aspirated were categorized as Benign, Malignant and Inadequate.

Out of the 330 cases diagnosed, majority were non neoplastic lesions (276) neoplastic were (54) [315]. Nodular goiter was found to be the commonest among all the lesions with 106 cases [32%] showing high prevalence between 21-30yrs and a male to female ratio of 1:8.7. Clinical presentation in most of the cases was Multi Nodular goiter involving both the lobes. In a small fraction of cases [15%] it presented as solitary nodule. Association of Nodular goiter with Hashimoto’s thyroiditis was found in two cases and in one case Papillary Carcinoma.

27 cases of Adenomatous hyperplasia were diagnosed of which 26 were females. Solitary nodular presentation was found in 22 %{ 6} cases. Common age group affected were 41- 50yrs. Cases of simple goiter diagnosed were 25, all in women, with a peak incidence in 21-30yrs.

15 cases of cystic lesions were diagnosed, mostly in the 31-40yrs age group with a female preponderance [12 females and 3 males].

Thyroiditis cases which were 94 presented as diffuse swellings involving the entire gland in the 2^nd to 5^th decade. Lymphocytic thyroiditis was diagnosed in 30 cases of which 2 were males. All the cases of Hashimotos thyroiditis [59] and granulomatous thyroiditis [5] were diagnosed in middle aged women.

39 cases were diagnosed as Follicular neoplasms, of these 34 were females and 5 were males. Clinical presentations of all these Follicular neoplasms were solitary nodules. They were commonly diagnosed in the 3rd to 4^th decades. Malignant neoplasms comprised 15 cases, Papillary Carcinoma accounting for 13 cases [86.67%] and the remaining two were Medullary Carcinoma and Anaplastic Carcinoma [13.33%]

Most of the Papillary Carcinomas were diagnosed in the 2^nd -3^rd decade and the female to male ratio was 3:1. Both the Medullary and Anaplastic Carcinomas were diagnosed in the 40-50yrs age group and in males. Surgical excision was done in 58 cases. Out of these, 26 patients with cytological diagnosis of Nodular goiter showed consistent picture in 17 cases. The remaining 11 cases were inconsistent. 6 cases were Follicular Adenomas, 2 cases were Papillary Carcinomas and 1 case of Thyrotoxicosis.

5 Cases diagnosed as cystic lesions were biopsied, 4 cases showed consistent picture (2 cases of thyroglossal cyst & 2 cases of infected cyst) and one case showed Nodular goiter. 18 cases diagnosed as Follicular neoplasms were subjected to histopathological examination. 12 cases showed Follicular Adenoma and two cases showed Follicular Carcinoma. The remaining 4 cases were hyperplastic lesions of MNG. 4 Cases of Papillary Carcinoma, 1 case of Anaplastic Carcinoma and 1 case of Medullary Carcinoma were excised and the histopathology was consistent in all the cases. 3 Cases were reported as inadequate on FNAC but after excision showed Follicular Adenomas.

As follicular carcinomas cannot be differentiated from follicular adenomas on cytology we considered 12 cases of follicular adenoma and two cases of follicular carcinoma as true positive. These 14 cases of follicular neoplasms, 4 cases of papillary carcinomas, one case of medullary carcinoma and one case of anaplastic carcinoma were considered as true positive (total20). 4 cases of MNG which were diagnosed as follicular neoplasms on cytology were considered as false positive. 2 cases of papillary carcinoma and 6 cases of follicular adenoma which were diagnosed as nodular goiter on cytology were considered as false negative.

The 18 cases of nodular goiter on FNAC ( excluding 2 cases of papillary carcinoma and 6 cases of follicular adenoma) and five cases of cystic lesions were found to be non neoplastic on histopathology and were considered as true negative.

Table 2. Showing distribution of neoplastic & non neoplastic cases

Table 3. Showing details of FNAC

Table 4. showing the lesions diagnosed on FNAC

Figure 1. Chart showing distribution of lesions

Table 5. Showing age wise distribution of cases

Figure 2. Chart showing age wise distribution of cases in the study

Table 6. showing common affected age group

Table 7. Showing sex wise distribution of cases

Figure 3. Chart showing sex wise distribution of cases in the study

Table 8. Showing lesions with solitary nodular presentation

Table 9. Showing percentage of non neoplastic lesions

Figure 4. Chart showing distribution of non neoplastic lesions

Table 10. Showing percentage of neoplastic lesions

Figure 5. Chart showing distribution of neoplastic lesions

Table 11. Showing number of cases subjected to HPE

Table 12. Showing Cytological Vs histopathological correlations

Table 13. Showing Histopathological correlation