Utility of Fine Needle Aspiration Cytology of Lymph nodes

Background: The incidence of lymphadenopathy appears to be increasing, especially among young adults all over the world. Their frequent involvement in regional and systemic diseases and their easy accessibility make the cytomorphological study of lymph nodes a permanent activity of pathologists. Inflammatory and immune reactions are the most frequent causes of lymph node enlargement and are self limiting in majority of cases. Lymphoid tissue undergoes reactive changes to a wide variety of antigenic stimuli. Tuberculosis, which is common in India, can also be diagnosed by cytology of affected lymph nodes. Lymph nodes are also affected as a result of primary neoplasm of the node itself and from metastasis of malignant neoplasm from regional and distant organs. With the advent of FNAC, most of the inflammatory, reactive and neoplastic conditions can be diagnosed without biopsy. It has the advantage that it can be done safely, rapidly and cheaply with minimal trauma at an outpatient setup or at the bedside. Material and Methods: This study was conducted at our institute which caters to patients belonging mostly to the lower socioeconomic group, after IEC [Institute Ethics Committee] approval. Written informed consent was obtained from all patients. It included 355 patients with lymphadenopathies at various sites. Acellular aspirates were excluded from the study. FNAC was conducted with the help of a 22 guage disposable needle attached to a 20cc syringe. Smears were fixed in 95% ethyl alcohol and stained with Haematoxylin and Eosin as well as Papanicolaou stains. Leishman stain was done on air dried smears. The cases suspected as Lymphoma were confirmed by biopsy or referred for Immunohistochemistry. The results expressed as percentage were tabulated. Results: Maximum numbers of patients were diagnosed with Reactive Lymphadenopathy 122/355 (34.36%), followed by Chronic Granulomatous Inflammation 72/355(20.28 %),Metastatic Lymphadenopathy 65/355(18.30 %), Acute Suppurative Lymphadenopathy 40/355 (11.26%), Tuberculous Lymphadenopathy 28/355 (7.88%), Primary neoplasm 14/355 (3.94%), Non Specific Lymphadenopathy 10/355 (2.81 %) and Sinus Histiocytosis 4/355 (1.12%). Histopathological correlation was available only in 36/355 cases. The correlation was correct in 32/36 cases [88.88%], making the sensitivity of the procedure 72.2%. In case of malignancies the histopathological correlation was 100%. Conclusion: FNAC is a safe, simple & inexpensive definite diagnostic procedure to render a prompt diagnosis for lymph node enlargements, especially in lymph node aspirates where biopsies are not done routinely.