Role of FNAC in Diagnosis of Malignant Lymphadenopathy: A Five-Year Cross-sectional Study at A Tertiary Care Centre, Mumbai, India

Abstract

Introduction: Fine Needle Aspiration Cytology (FNAC) of the lymph node is a simple tool in the diagnosis of suspected and unsuspected primary and secondary lymph node malignancy. It is a useful first-line investigation to distinguish between infective and malignant lymphadenopathy, especially in a low-resource setting like our country. Aim: To study the utility of FNAC in the diagnosis of lymph node malignancy and to evaluate the efficacy of cytology in diagnosing the primary site of malignancy in case of metastasis. Materials and Methods: A cross-sectional retrospective and prospective study was conducted for a five-year period from July 2015 to June 2020, in the pathology department of Dr. RN Cooper Municipal General Hospital, Mumbai, Maharashtra, India. A total of 112 patients diagnosed with malignancy on FNAC of lymph nodes were studied. The FNAC procedure was performed by cytopathologists using a 23/24G needle attached to a 10 ml syringe. The alcohol-fixed smears were stained with Haematoxylin & Eosin (H&E) stain and Papanicolaou (PAP) stains, while the airdried smears were stained with Giemsa stain. Diagnosis was based on cytomorphological features and clinical presentation. Results: A total of 112 patients were diagnosed with malignancy on FNAC, of which 90 were males and 22 were females, with a male-to-female ratio of 4:1. Cytological analysis of these nodes revealed metastasis in 98 cases (87.50%) and lymphoma in 14 cases (12.50%). The maximum number of patients were in the 51-60 years age group, with 38 cases (33.92%). The most common site of involvement was cervical lymph nodes, with 75 cases (66.96%). The most common cytological diagnosis was metastatic squamous cell carcinoma in 65 cases (58.02%), followed by metastatic un-differentiated carcinoma in 26 cases (23.20%). Conclusion: Fine Needle Aspiration (FNA) is a simple, safe, accurate, cost-effective, and valuable tool in the evaluation of malignant lymphadenopathy. Malignant diseases were easily diagnosed by this simple diagnostic procedure. In the case of a diagnosis of lymphoma, surgery can be completely avoided. It helps in planning further surgical management for metastatic disease, where definitive operative intervention can be performed in one session. In the case of an un-detected primary tumour, FNAC directs further investigations towards the possible primary site.