MORPHOLOGICAL SPECTRUM AND ACCURACY OF FINE NEEDLE ASPIRATION CYTOLOGY IN TUBERCULOUS LYMPHADENITIS

Abstract

Abstract Background: Fine needle aspiration is an easy, cost effective and minimally invasive procedure which can help in the diagnosis of tuberculous lymphadenitis. The aim of the present study is to determine the capability to diagnose tuberculous lymphadenitis directly on fine needle aspiration cytology (FNAC) smears. Material and Methods: 85 fine needle aspirations from superficial lymph nodes were compared with their respective biopsies at the Armed Forces Institute of Pathology, Rawalpindi from January 1991 to December 1991. Both the FNAC smears and lymph node biopsy sections were submitted for AFB stains. A part of the aspirate was cultured on Lowenstein-Jensen slopes for Mycobacterium species. Results: Granulomatous changes were seen in 35 cases on fine needle aspiration diagnosis made prior to surgery. On histology a diagnosis of tuberculous lymphadenitis compatible with tuberculosis was made in 44 cases. Comparing the 35 cases showing granulomatous changes on FNAC smears, 34 (97%) cases complied with the histopathological diagnosis. One false positive case on FNAC smear occurred which was diagnosed as follicular large cell lymphoma on lymph node biopsy. Out of 44 cases diagnosed as tuberculous lymphadenitis on lymph node biopsy sections, on FNAC 10 (23%) were false negative. The rest of the 34 cases (77%) on FNAC smear showed granulomas, caseation necrosis and inflammatory changes compatible with tuberculosis. Conclusion: A sensitivity of 77% and specificity of 97% was calculated for FNAC in diagnosis of tuberculous lymphadenitis. It was found that the accuracy of FNAC diagnosis for tuberculous lymphadenitis was significantly related to the extent of caseation necrosis in the lymph node (P value < 0.01).

Keywords

• biopsy
• caseation necrosis
• epithelioid granuloma
• fnac
• lymph node
• tuberculous lymphadenitis.