CORRELATION OF FINE NEEDLE ASPIRATION CYTOLOGY AND HISTOPATHOLOGY OF THE NECK SWELLINGS PRESENTING AT NATIONAL ACADEMY OF MEDICAL SCIENCES, KATHMANDU, NEPAL

Introducon Neck masses are frequently found in clinical pracce. A spectrum of pathological lesions ranging from inﬂammaon to benign and highly malignant manifestaon is observed. Fine needle aspiraon cytology (FNAC) of neck masses is a quick, easy, safe and cheap technique in the diagnosis which has been a well-accepted procedure in diagnosing various swellings.


INTRODUCTION
A lump is the most common clinical condi on found in the neck. The common neck lump are lymphadenopathies, thyroid 1 swellings, metasta c carcinoma, and salivary gland swellings.
In 1930 Mar n introduced Fine needle aspira on cytology, since then it has become one of the popular diagnos c tool 2 of palpable lumps. It is a easy, fast and inexpensive method used for sampling superficial masses of the neck and is commonly performed in the outpa ent clinic. It causes least trauma to the pa ent and carries negligible risk of 3,4 complica ons. It is performed under local anesthesia and is usually helpful if a neck lump is suspected to be malignant. The evidence of spread of tumor via the track caused by the 5 fine hypodermic needle used is lacking. It is can be both 6 diagnos c as well as therapeu c in a cys c swelling. It does not provide the detail architecture as histology but can 7 provide cells from whole lesion from many aspira ons. Histopathology is the gold standard technique for diagnosing any swellings which also provide detailed architecture. However it requires exper se, opera on theatre and comprises more complica ons. It cannot be performed in OPD, is more expensive and requires more manpower.
The aim of this study is to assess the spectrum of neck masses and to determine the accuracy of FNAC in detec on of various lesions in Na onal Academy of Medical Sciences, Bir Hospital.

METHODOLOGY
This study was conducted at Bir Hospital, Kathmandu as a Hospital based descrip ve cross sec onal study. The study was conducted from March to September 2014. First 50 cases of neck swellings presented in surgical OPD or admi ed in the hospital for various reasons were selected as a sample size (50 cases taken because of me limit, and also similar study conducted in surgery department of Postgraduate Medical Ins tute, Lady Reading Hospital Peshawar by Tariq Ahmad et al).
Both sexes above 15 years of age, with a neck swelling were included in the study. Any pa ent diagnosed previously by histopathology was excluded from the study.
FNAC and histopathology was done for all the pa ents a er ge ng their consent and without monetary burden by approval from respec ve authori es. The pathology department performed the FNAC and biopsy specimen was obtained from surgery department in opera on theatre and sent for histopathological examina on.
FNAC was performed by 23 gauge needle and Papanicolaou and Giemsa stains were used for staining. Likewise, the biopsies were fixed in 10% formalin, sec ons made and were stained with hematoxylin and eosin. Then histo-cytological comparison was done. In rela on to histopathological study the sensi vity, specificity and accuracy rate of FNAC was measured.
Interim analysis of data was performed upon comple on of the study. The data was entered into the computer using SPSS 22.0. It was rechecked by reading from the computer and checking the original source. Sta s cal Analysis was done by using chi-square test for categorical correla ons and independent t-test for con nuous variables

RESULTS
A total of 50 pa ents were included in the study. The maximum number of pa ents were in the age group of 15-40 (n=27). Both males and females were equal in number in the study. Lymphnodes (n=22) were highest in number to occur among the neck swellings. Others include thyroid (n=17), salivary glands (n=10), so ssues (n=1).  and metasta c carcinoma of LN , NHL, and pleomorphic adenoma of salivary gland found in 10% of cases each. Tubercular lymphadeni ts was the most common findings of the cervical lymphadenopathy (n=9) followed by NHL and metasta c carcinoma (n=5) each and lastly was nonspecific lymphadeni s (n=3). Out of the total tubercular lymphadeni s (n=9) only 6 could be correctly diagnosed by FNAC and 3 of the result were inconclusive with accuracy rate of 66.7%. The cause of the low accuracy rate of the TB lymphadeni s is because of the inadequate aspirate of the specimen which showed inconclusive results. Literature shows that the accuracy rate of FNAC in tubercular lymphadeni s is 90-10 100%. one case NHL was wrongly diagnosed as non-specific lymphadeni s. Out of 5 cases of metasta c carcinoma 2 were inconclusive with accuracy rate being 60%. Out of the total thyroid cases papillary carcinoma of thyroid is the most common findings (n=7) followed by follicular adenoma and colloid goiter with 3 cases each. One cases of thyroid follicular adenoma was wrongly diagnosed as nonspecific thyroidid s. 1 case of colloid goiter was diagnosed as cys c lesion. It may be impossible to differen ate cellular colloid goitre from follicular lesion, and it is also not possible to differen ate a follicular adenoma from a carcinoma, as it requires examining the whole lesion to determine capsular 11 and vascular invasion for diagnosis. FNAC could not dis nguish follicular adenoma from follicular carcinoma so the diagnosis of follicular neoplasm was made (n=2). Except for nonspecific throidid s (accuracy rate 50%) all the cases have 100% acccracy rates. In this study, in diagnosing the thyroid gland disorders, the highest degree of sensi vity (94.12%) shows that FNAC can be considered as a first line inves ga on of such swellings.
The most common cause of salivary gland swelling is pleomorphic adenoma (n=5) followed by chronic sialadeni s (n=3) with only one case of malignancy diagnosed as mucoepidermoid carcinoma. In a study conducted by Gills 12

MS et al. in 2001 in
Pakistan the most common benign salivary gland tumour was pleomorphic adenoma (84.5%) and the most common malignant neoplasm was mucoepidermoid carcinoma (56.9%). Accuracy rate is 100% for all the salivary gland diseases except warthin's tumour which was wrongly diagnosed as benign cys c lesion, accuracy rate being 0%. 13 The accuracy rate ranged from 80.4 to 98%. Lipoma was the only lesion from the so ssue and miscellaneous group, with 100% accuracy rate. The p value for the FNAC Vs HPE for all the sites including the lymph node, thyroid gland , salivary gland is <0.05 which is sta s cally significant that is there is strong evidence of rela onship between the FNAC and the HPE findings of the neck swellings. Comparison of other studies with our study Table 4: Devkota H et al CONCLUSION Fine Needle Aspira on Cytology is a simple, can be performed under local anesthesia and quick results are obtained. It serves as an alterna ve to histopathological examina on and can be used as a primary diagnos c tool in diagnosing the neck swellings. There was a good accuracy rate between the cytological and histological findings. It has high sensi vity rate, however there are few drawbacks because of the inconclusive results misleading diagnosis of various cys c lesions of neck. Thus, in the diagnosis of neck swellings FNAC can be regarded as a first line of inves ga on.

RECOMMENDATIONS
Fine needle aspira on cytology can be used as an ini al diagnos c tool for the evalua on of neck masses in addi on to clinical examina on. Further study with larger sample size should be carried out in our community to verify the conclusion derived in this study.

LIMITATION OF THE STUDY
The study was carried out in short period of me; hence large sample size could not be collected. Possibili es of the sampling bias as the first 50 cases were taken from various departments.

ACKNOWLEDGEMENT
The author would like to acknowledge the en re pa ents who par cipated in the study; Dr. Yahun Chandra Sibako , Prof. General Surgery who guided me throughout and others who are involved directly and indirectly to make this study a success.