Fine needle aspiration cytology of head and neck lesions and its correlation with histopathology

Correspondence: Dr Rakesh Pathak, MBBS, MD Lecturer, Department of Pathology, Nepal Medical College Teaching Hospital, Jorpati, Kathmandu, Nepal Email: dr_rakesh@hotmail.com Background: Fine needle aspiration cytology is a minimally invasive technique used in the initial diagnosis of different types of lesions located in head and neck region commonly originating from cervical lymph node, thyroid gland, salivary glands and soft tissues. The objective of this study was to evaluate the diagnostic accuracy, sensitivity and specificity of FNAC in various head and neck lesions in correlation with their histopathological examination.

review committee.The patients had undergone preoperative FNAC and subsequently histopathological examinations (HPE) were performed in the Department of Pathology, BCH and the Department of Pathology, NMC from August 2014 to July 2015.All patients were asked about history related to head and neck swelling, probable etiological cause, family history of tuberculosis and other relevant disease.Informed consent from each individual was taken.Patients with non-diagnostic type of FNAC and previous history of chemotherapy, radiation therapy or any antituberculosis drugs were excluded from the study.FNAC was performed by 22-23 gauze needle with 10ml syringe.The aspirated material was smeared on minimum 2 clean glass slides, wet fixed or air dried followed by region including various neoplastic and non-neoplastic lesions of lymph node, salivary gland, thyroid gland and other soft tissues. 5An early diagnosis and differentiation of such lesions from inflammatory to neoplastic play crucial role on planned treatment. 6The prime objective of the study was to assess the utility of FNAC in diagnosis of head and neck lesions and correlate the cyto-morphological features with histo-pathological findings.

MATERIAL AND METHODS
The present study comprised of 209 cases of palpable head and neck masses, 139 cases were from Bhaktapur Cancer Hospital (BCH) and 70 cases from Nepal Medical College (NMC).Ethical clearance was obtained from institutional Pathak R et al.  staining with Giemsa and Papanicolaou (PAP).Similarly, biopsies obtained from those patients were fixed in 10% formalin and processed.Different sections so obtained were stained with Hematoxylin and Eosin (HE) stain.Finally stained sections were observed under microscope and cyto-histopathological correlation was made.Data were processed and analyzed using SPSS version 17.

RESULTS
The present study included 209 cases of head and neck lesions ranged from 1 to 82 years of age in which 55.5% were male and 44.5% were female.Maximum incidence was observed below 50 years 127 (61%) cases and remaining 82 (39%) cases were above 50 years.
Among the head and neck lesions FNAC presented at BCH and NMC, lymph nodes showed the highest incidence followed by thyroid gland, soft tissues and salivary glands.Male predominance was seen in lymph nodes (64%) and salivary gland (79%) whereas in thyroid gland (65%) and soft tissues (67%) female predominance was observed (Table 1).

DISCUSSION
Head and neck lesions are the commonly encountered clinical conditions.In this study the most common sites for the occurrence of head and neck masses were lymph nodes followed by thyroid, other soft tissues and salivary gland.
Our findings were comparable to other studies that have shown lymph nodes as the most frequent site for FNAC in head and neck region. 7,8ong 128 cases lymph node lesions, reactive lymphadenitis was the most common pathological finding followed by metastatic carcinomas, granulomatous lymphadenitis, lymphomas and abscess.6][7] Out of 66 cases were available for HPE, NHL (27.3%) was the commonest pathological findings followed by granulomatous lymphadenitis (25.8%), metastatic carcinoma (19.7%), reactive lymphadenitis (10.6%),HL (7.6%), Kikuchi fujimoto disease (4.5%) and abscess (4.5%).Four false negative cases for malignancies at lymph nodes were reported from FNAC which were later confirmed by histo-pathological examination.
Out of 40 thyroid FNAC cases only 11 cases were obtained for HPE correlation.These thyroid lesions revealed colloid goiter (36%) and papillary carcinoma (36%) as the predominant finding followed by hyperplastic nodule and hurthle cell neoplasm.Rathod et al and Rajbhandari et al observed similar findings with maximum incidence of colloid goiter and then papillary carcinoma. 6,9A study by Singal et al reported colloid goiter as the most commonly observed disorder in thyroid region similar to our finding. 10out et al. found colloid goiter as the most common among thyroid swelling followed by colloid goiter with cystic degeneration. 12ong 14 FNAC cases of salivary gland, only 6 were received for HPE correlation.Sialadenosis and sialadenitis together comprised 3 cases (50%) whereas mucoepidermoid carcinoma accounted 2 cases (33.3%) and 1 case (16.7%) of acinic cell carcinoma were observed.Chronic sialadenitis is the most common non-neoplastic lesion observed in salivary gland followed by neoplastic pleomorphic adenoma. 5,9,13ther studies reported pleomorphic adenoma as the most common lesion found in salivary gland.2,7,8,10,14,15.A study by Rathod et al found mucoepidermoid carcinoma as the commonest malignancy in salivary gland similar to our study. 6 this study we obtained 27 FNAC cases of soft tissues whereas 20 samples were available for HPE.We observed 12 (60%) cases of epidermal cyst which was the most common soft tissue lesions followed by lipoma, hemangioma and schwannoma.Suryawanshi et al reported epidermal cyst comprised maximum benign lesions and then lipoma similar to our study. 5A study by Singal et al found the lipoma as the common soft tissues lesion followed by epidermal cyst and hemangioma which was not in accordance with our study. 10 this study we correlated the FNAC results with the HPE findings of available specimens.Four false negative for malignancy were reported initially by FNAC.Being blind sampling procedure, we might not get proper samples, samples with mixed macrophages and lymphoid tissues in the specimen might have created such misinterpretations which were later confirmed by HPE.However 44 (67%) FNAC cases of lymph nodes were found consistent with HPE findings however, thyroid gland, salivary gland and other soft tissues showed 100% consistent with HPE.

CONCLUSION
FNAC is recommended as a safe, reliable, quick, inexpensive and minimally invasive technique in the diagnosis of head and neck lesions.It serves as a complementary diagnostic procedure to histopathological examination in the diagnosis and management of palpable head and neck lesions.