Diagnosis of tuberculous lymphadenitis using fine needle aspiration biopsy

Abstract

Background: Tuberculous lymphadenitis is the commonest form of extrapulmonary tuberculosis. However, the optimal approach to diagnosis, employing biopsy by either fine needle aspiration (FNA) or surgical excision, remains uncertain. Aims: To evaluate the diagnostic value of biopsy using each of the component diagnostic modalities of FNA (microscopy, cytology and culture), and compare these with excision biopsy in the diagnosis of tuberculous lymphadenitis in a predominantly migrant population in Melbourne. Methods: A retrospective examination of tuberculous lymphadenitis cases presenting to Western Health over 12 years was conducted. Using a reference method of positive culture of Mycobacterium tuberculosis, the diagnostic sensitivities of each modality employed in FNA were determined. Results: Forty‐two subjects having FNA and 30 having excision biopsy as the initial investigation were compared. Among specimens obtained by FNA, sensitivity of microscopy was 18% (95% confidence interval (CI): 5–40%) and sensitivity of cytology was 38% (95% CI: 20–59%). For specimens obtained by excision biopsies, sensitivities for microscopy and histology were 17% (95% CI: 2–32%) and 96% (95% CI: 88–100%) respectively. Sensitivity of culture performed on FNA specimens was 86% (95% CI: 65–97%). Conclusions: Given the relatively high sensitivity of mycobacterial cultures from FNA, this study supports its routine use as the initial investigation in most patients with suspected tuberculous lymphadenitis. Microscopy and cytology add relatively little to the clinical utility of FNA.

Fine-needle aspiration for diagnosis of tuberculous lymphadenitis in children in Bangui, Central African Republic

“…The conventional Ziehl-Neelsen method on smears is widely used and plays a key role in TB diagnosis, but it has a poor sensitivity in aspirates because of the small number of mycobacterial cells. Löwenstein-Jensen culture showed that 88 (67.2%) samples were positive, confirming the greater sensitivity of culture than Ziehl-Neelsen staining, and in agreement with recent reports of culture sensitivity of 65.8% [15], 69% [16] and 86.4% [14]. …”

“…Microscopy showed the presence of potential TB bacilli in 42.7% of the aspirates, and culture identified TB in 67.2% of cases. The percentage of Ziehl-Neelsen-positive strains was much higher than the 18% observed by Knox [14] but close to those reported recently (45% [15] and 48.2–51.8% [16]) with light-emitting diode microscopy in studies of mycobacterial lymphadenitis in fine-needle aspirates from children. The conventional Ziehl-Neelsen method on smears is widely used and plays a key role in TB diagnosis, but it has a poor sensitivity in aspirates because of the small number of mycobacterial cells.…”

Diagnostic Accuracy of Fine Needle Aspiration Cytology in Diagnosis of Tuberculous Lymphadenitis

“…Ellison et al 13 reported a sensitivity of 25% and a positive predictive value of 65% in USA. Knox et al 6 found sensitivity of cytology 38% in a non-endemic area. In this study sensitivity, specificity, positive predictive value and negative predictive value of FNAC were 79.7%, 48.1%, 31.9% and 88.6% respectively.…”

“…Other studies also found female predominance. 4,6,7 However, Bezabih et al 5 found slight male predominance. In this study cervical lymph node involvement was found most commonly (95.9%) followed by axillary lymphadenopathy.…”

“…Other similar studies also found cervical lymphadenopathy in the majority of cases followed by axillary lymphadenopathy. [4][5][6]8,9 Cytomorphological diagnosis of TB was made when there was presence of epithelioid cells singly or in clusters (granuloma) with caseous necrosis. FNA has become the first-line diagnostic technique in endemic areas, where the mere presence of epithelioid cell/granuloma indicates tuberculosis until proven otherwise.…”