HEAD AND NECK SWELLING: A CYTOPATHOLOGICAL PERSPECTIVE IN A HOSPITAL BASED STUDY

1* 2 3 Sujan Shrestha , Dinesh Khadka , Sujita Bhandari Introduc on Fine Needle Aspira on Cytology is a simple, rela vely less painful, cost-effec ve minimal invasive procedure commonly employed in the evalua on of head and neck swellings. There are limited studies on cytological findings of head and neck swelling in Nepal. Objec ves The objec ve of this study was to study cytological findings of head and neck swellings. This study further intends to classify the nature of the swelling and use standardized interna onal repor ng system wherever required. Methodology This is a retrospec ve the hospital-based study done in Department of Pathology at the Helping Hands Community Hospital, Kathmandu between 1 January 2019 and 32 December 2019. Slides of all FNAC from head and neck swelling done during this period was retrieved and evaluated for the study. Chi-Squared (χ2) test was used to inves gate the significance of epidemiological and cytological parameters. Result Males (56%) had more head and neck swelling than females (44%). The younger age group of less than twenty-five(< 25) years had more frequency of head and swelling followed by the older age group of more than fi y (>50) years. The most common site for Fine needle aspira on was lymph nodes (58%) followed by thyroid (23%). Salivary gland swelling swellings were the least frequent (5%). Of all the swelling, 17% of cases were a ributed to malignant causes. Infec ve/Inflammatory causes (55%) were the most common cause of lymph node swellings. Metasta c carcinoma was more prevalent in the older age group of more than fi y (>50) years with a prevalence of 21% of total cases studies. Most of the thyroid swellings were found to be benign (58%) whereas 16% of thyroid swellings belonged to the malignant category. The total numbers of salivary gland swelling were the least with 55% of cases having benign neoplas c e ology. Diagnosis of developmental anomalies like a thyroglossal cyst, lymphangioma, branchial cyst, though rela vely less common (10%) were also made with the help of cytologic studies. Conclusion Fine Needle Aspira on is a useful method to differen ate benign and infec ve cases of head and neck swelling from neoplas c cases.


Result
Males (56%) had more head and neck swelling than females (44%). The younger age group of less than twenty-five(< 25) years had more frequency of head and swelling followed by the older age group of more than fi y (>50) years. The most common site for Fine needle aspira on was lymph nodes (58%) followed by thyroid (23%). Salivary gland swelling swellings were the least frequent (5%). Of all the swelling, 17% of cases were a ributed to malignant causes. Infec ve/Inflammatory causes (55%) were the most common cause of lymph node swellings. Metasta c carcinoma was more prevalent in the older age group of more than fi y (>50) years with a prevalence of 21% of total cases studies. Most of the thyroid swellings were found to be benign (58%) whereas 16% of thyroid swellings belonged to the malignant category. The total numbers of salivary gland swelling were the least with 55% of cases having benign neoplas c e ology. Diagnosis of developmental anomalies like a thyroglossal cyst, lymphangioma, branchial cyst, though rela vely less common (10%) were also made with the help of cytologic studies.

Conclusion
Fine Needle Aspira on is a useful method to differen ate benign and infec ve cases of head and neck swelling from neoplas c cases.

INTRODUCTION
Swelling on the head and neck region are chief complaints that bring pa ents to the hospital for Fine needle aspira on (FNA) procedure. Fine needle aspira on cytology (FNAC) is a cytodiagnos c method based on cytomorphological observa on of cells obtained using a fine needle. Fine needle aspira on cytology is one of the first lines of inves ga on in the evalua on of any swelling as it is rela vely easy, rapid, cost-effec ve and minimally invasive 1 procedure. The u lity of needle aspira on for diagnos c 2 purposes has been discussed as early as 1847 by Kum. In 1930, Memorial Sloan Ke ering centre rediscovered the u lity of needle biopsy of head and neck mass but the procedure failed to get popularity as wide bore needle was a ributed at that me for seeding of malignant cells. In 1950 the needle size was modified following which the number of morbidi es associated with previous procedures showed significant reduc on resul ng in a resurgence in the use of 3 FNAC. The head and neck region consist of variable ssue types in close proximity rendering difficulty in incisional biopsy. In addi on, wide range of primary and metasta c neoplasm are responsible for head and neck region swelling which makes FNAC more advantageous. The other significant benefits of FNAC include minimal physical and psychological pain, discomfort, elimina on of a two-stage procedure for 4 diagnosis and treatment. The objec ve of this study was to study cytological findings of head and neck swellings. This study further intends to classify the nature of the swelling and use standardized interna onal repor ng system wherever required. The purpose of this study was to evaluate the distribu on and determine the spectrum of cytological findings inpa ents presen ng head and neck swellings in a community hospital.

Study design, popula on, and data collec on
A retrospec ve cohort study was conducted on the data obtained on all FNAC performed cases in the Department of Pathology at the Helping Hands Community Hospital, Kathmandu between 1 January 2019 and 31 December 2019. All the FNAC cases performed by the pathologists and imaging guided (Ultra sonogram guided or Computed Tomography Guided) FNA performed by the radiologists from the head and neck masses were included in the study popula on. The FNAC slides were retrieved and evalua on was done by the primary author. Cases in which the cellular yield was poor and thus inadequate for evalua on were excluded from the study. The pa ent informa on report included the demographic informa on, anatomical loca on of the swellings, the severity of the case, and the procedure undertaken. The Bethesda system or repor ng thyroid cytopathology was adopted while repor ng thyroid FNAC and the Milan system for repor ng salivary gland cytology 5, 6 was adopted while repor ng salivary gland FNAC. Findings were further classified into specific infec ve/inflammatory, benign, suspicious, and malignant categories.

Sta s cal analysis
Data were organized for analysis in Microso Excel 2016 (Microso Corpora on, Redmond, WA, USA) and the exploratory data analysis was performed. For convenience, the pa ent's age variable was categorized into three groups: younger age group (<25 years), mid-age group (25-50 years), and old-age group (50 years above). Chi-Squared (χ2) test was employed to inves gate the significance of suitable epidemiological and cytological parameters. The level of sta s cal significance was set at P < 0.05. Sta s cal analyses were conducted using 7,8 func ons available in the packages 'epiR', in R. The ethical clearance was obtained from the Helping Hands Community Hospital for the study.
Details of the loca on of anatomical loca on of swellings and number are summarised in Table 2. The most frequent cases were lymph nodes with 90 cases while 36 cases of gland swellings, 9 cases of salivary glands and 19 cases of so ssues swellings were observed across the meperiod. The number of enlarged lymph nodes stra fied by the descrip on of the type of e ologies in the study period are summarized in Table 3. Infec ve/Inflammatory e ology which included tubercular lymphadeni s (Figure 1), granulomatous lymphadeni s, suppura ve lymphadeni s ( Figure 3) and Kikuchi lymphadeni s were the most common findings in younger age groups (< 25 years) whereas malignant cases ( Figure 2) which included metastases of adenocarcinoma (Figure 4), squamous cells carcinoma, small round cell carcinoma, undifferen ated carcinoma were the most common findings in older age group (>50 years). Reac ve lymphadeni s are those groups of enlarged lymph nodes which revealed polymorphous lymphoid popula on of cells sugges ve of various stages of matura on, with occasional ngible body macrophages. However, there were no a typical cells or morphological changes like granulomas forma on, necrosis on cytologic examina on. Regardless of the age, Tubercular lymphadeni s (34%) was the most common cause of lymph node enlargement. The odds of lymph node cases for males was 1.75 (95% CI 0.92 -3.36) mes that of females. Table 3. Number and incidence of enlarged lymph node e ologies stra fied by age group (n = 90). Of the 50 infec ve/inflammatory pathologies, 31 cases (62%) had tubercular e ology which was confirmed on the examina on of stained slides. The remaining 19 cases (38%) were those of granulomatous lymphadeni s 8 cases (16%), acute suppura ve lymphadeni s 8 (16%) cases, and Kikuchi lymphadeni s 3 (6%) cases. The two cases in the younger age group (< 25 years) had findings sugges ve of malignancy: one Hodgkin lymphoma and the other metasta c papillary thyroid carcinoma. Adult age group more likely to suffer from malignancy than were younger age group (χ2 test sta s c 11.635; df = 1; p <0.001). Metasta c adenocarcinoma was the most common finding among the malignant causes. Of 20 malignancy cases, 19 cases revealed features of and a case metasta c carcinoma showed features of primary malignancy as Hodgkin's lymphoma. Metasta c adenocarcinoma was seen in 11 cases followed by squamous cell carcinoma in three cases. All the metastases were present in the elderly age group of >50 cases except for a single case of papillary carcinoma thyroid which was seen in the age group < 25 yrs. Two cases were signed out as posi ve for malignancy since further categoriza on could not be done based on cytomorphology alone. FNAC performed in 36 cases of thyroid swelling, of which 4 (11%) cases were reported as inadequate for evalua on.
Twenty-one cases of 36 cases (58%) were diagnosed benign which included lymphocy c thyroidi s, nodular colloid goiter, adenomatoid nodule, and subacute thyroidi s. Six cases (16%) were reported as papillary carcinoma thyroid (Fig 5) and three cases (8%) were reported for papillary carcinoma thyroid. Females were more likely to have thyroid swelling compared to males 2 (χ test sta s c 5.924; df= 1; p <0.01). Table 5: Number of salivary gland swelling categorized based on the Milan system for repor ng salivary gland cytology (n = 9).

DISCUSSION
The study illustrates the u lity of FNAC at various anatomical loca ons. The majority of FNA specimens were obtained from the lymph nodes followed by thyroid swelling. The results from this study accords with previous studies that obtained majority of aspirates from the lymph 9 nodes for FNAC. Consistent with the literature, this research found that adults have higher incidence of 10 malignancy. This is likely due to the habit of smoking and tobacco chewing. Another interes ng finding is that females were more likely to have thyroid swelling compared to males. The finding was in consistent with Raina et al. and Kamra et al. who have demonstrated that gene c and environmental factors play 11,12 role in thyroidi s in females. Clinical and radiological examina on findings of head and neck masses are not always sufficient to decide on the further line of management. Cytological examina on of the material obtained by FNA might prove to be an effec ve tool in deciding further line of management of these swelling. FNAC procedure is reported to have 76.5% specificity and 78% sensi vity for iden fying malignant lateral cervical 13 lesions. Regarding sensi vity and specificity of FNAC, a study reported sensi vity of 89% and specificity of 57% in neck lymph nodes, 64% sensi vity and 100 % specificity in salivary gland swelling, 62% sensi vity and 86% specificity in 14 thyroid gland swelling. The overall accuracy ra o, specificity, sensi vity, nega ve predic ve value and posi ve predic ve value of FNAC in the diagnosis of head and neck 15 masses were 83%, 85%, 81%, 84%, 83% respec vely. The study FNA followed by further supports the idea that 16 biopsy has high overall accuracy. It has a wide array of uses and provides confidence to confirm malignancy even in a clinically suspicious lesion though it should be noted that procedures require experienced cytopathologists for perfect execu on. In this study, males were predominant over females which agree with those obtained 17,18 by previous studies. In contrast to this, study by Singh et al. reported female predominance 19 in their study. Akhavan-Moghadam et al. reported 41% malignant cases, 20 19% cases benign neoplasm and 40% cases non-neoplas c. This finding broadly supports the work of other studies in this area where metasta c carcinoma to lymph nodes was 21 the most common type of malignancy. FNA of a thyroid nodule is indicated in various situa on such as pa ent with clinical symptoms of thyroid cancer, nodules 22 >1 cm with at least two ultrasound criteria of malignancy. According to the guidelines developed by Perros et al. FNA is also indicated when nodules of any size with extracapsular extension or indeterminate cervical lymph nodes, nodules of any size in a pa ent with a history of neck radia on, history of well-differen ated thyroid cancer in more than two first degree rela ves, medullary thyroid carcinoma or mul ple endocrine neoplasias (MEN) TYPE 2, increased 22 calcitonin level. The sensi vity of thyroid carcinoma detec on is approximately 60-90 % (in some cases up to 100%) and the specificity of 60- 23 100% in the hand of an experienced cytologist. The molecular gene c analysis of the FNA specimen will further improve the diagnos c accuracy with the iden fica on of addi onal genes involved in the pathogenesis of thyroid cancer. Repor ng of salivary gland cytology has been a challenging job because of the resemblance of neoplas c cells to normal salivary gland element, the heterogeneous nature of salivary gland lesion, the overlap between benign and malignant lesions, presence of cys c component and 24 oncocy c metaplasia. Reports have shown chronic sialadeni s as the most common non-neoplas c lesion with the overall accuracy of FNAC to be 83.8% with 77.7% 25 sensi vity and 86.3% specificity. In a more recent study, the diagnos c sensi vity was 94%, specificity was 97% and 26 the accuracy was 95%. The use of FNA -a method of aspira on biopsy cytology con nues to grow throughout the world. Improvements in using imagingand ultrasound have fuelled the growth of 27 FNAC among both interven onal radiologists and clinicians. In future, molecular gene cs methods will probably extend the diagnos c range of FNA beyond what is currently achievable with classic cytology.

CONCLUSION
Fine needle aspira on cytology being simple quick cost-Original Research Ar cle effec ve minimal invasive rela vely less painful procedure has proven to be quite a useful tool in the inves ga on of head and neck region swelling which poses more challenge due to not so easy anatomical terrain for an incisional biopsy study. It has the diagnos c ability to differen ate between inflammatory, benign malignant processes and thus aid in further management effec vely.

LIMITATION OF THE STUDY
The FNAC itself has its own limita ons to make specific diagnosis as men oned above in the discussion. Tissue biopsy is s ll considered the gold standard to make a final diagnosis in the evalua on of any swelling on the body.