Using Ultrasound Guided Needle Biopsy in Combination With GeneXpert MTB/RIF to Diagnose Epididymal Tuberculosis: a Study of 12 Cases

Abstract Objective: This study aims to investigate the diagnostic utility of percutaneous ultrasound-guided needle biopsy in combination with GeneXpert MTB/RIF for epididymal tuberculosis.Methods: Between March 2019 to March 2021, specimens obtained from 12 patients with confirmed epididymal tuberculosis by ultrasound guided needle biopsy were sent for pathology and laboratory examination at the Shandong Public Health Clinical Center. The laboratory examination included acid-fast staining, Mycobacterium tuberculosis culture by BACTEC MGIT 960, and the GeneXpert MTB/RIF test. The diagnosis and complications were comprehensively analyzed.Results: Among the 12 cases, seven cases had granulomatous inflammation and necrotic tissue, four cases had chronic inflammatory cells and necrotic tissue, and one case had chronic inflammatory cell infiltration. Furthermore, among the 12 patients, five patients were positive for Mycobacterium tuberculosis culture, two patients were positive for the acid-fast staining, and twelve patients were positive for the GeneXpert MTB/RIF assay. The sensitivity and specificity of the acid-fast staining, Mycobacterium tuberculosis culture and GeneXpert MTB/RIF in the diagnosis of epididymis tuberculosis were 16.67% and 100.00%, 41.67% and 100.00%, and 100.00% and 50.00%, respectively. The diagnostic value analysis of the three detection techniques indicated that the GeneXpert MTB/RIF technique (Kappa=0.63, AUC=0.75) is superior to the Mycobacterium tuberculosis culture (Kappa=0.17, AUC =0.71) and acid-fast staining (Kappa=0.05, AUC=0.58). Conclusion: Ultrasound guided percutaneous biopsy combined with GeneXpert MTB/RIF assay is extremely useful for diagnosing epididymitis tuberculosis and determining rifampin resistance, with superior sensitivity, specificity and AUC value.