Abstract
OBJECTIVE: To investigate how pathological types and sampling methods affect positivity rates of five diagnostic techniques in cervical lymph node tuberculosis. METHODS: We retrospectively analyzed 198 surgically confirmed cervical lymph node tuberculosis patients from Wuhan Pulmonary Hospital. Cases were stratified by pathological subtypes and collection methods. The specimens were tested using acid-fast bacillus smear microscopy, mycobacterium tuberculosis culture, quantitative polymerase chain reaction for tuberculosis DNA, simultaneous amplification and testing for tuberculosis, or GeneXpert. RESULTS: All 198 cases showed granulomatous inflammation. Liquefactive necrosis occurred in 91.92% (182/198) of cases, with caseous necrosis in 87.88% (174/198), adjacent soft-tissue necrosis in 57.07% (113/198), and suppurative inflammation in 20.20% (40/198). Solid alterations without liquefactive necrosis (coagulative necrosis/non-necrotizing lymphadenitis) comprised 8.08% (16/198). The overall etiological positivity rate was 90.40% (179/198). GeneXpert showed highest sensitivity (90.36%), followed by tuberculosis DNA (74.24%), simultaneous amplification and testing (40.22%), Mycobacterium tuberculosis culture (16.67%), and acid-fast bacillus smear (14.72%). Among 33 culture-positive cases, 32 (96.97%) were GeneXpert positive. Rifampicin resistance detected by GeneXpert was 5.62% (10/178). In specimens with caseous necrosis, soft-tissue necrosis, or liquefactive necrosis, GeneXpert positivity significantly exceeded tuberculosis DNA (all P < 0.01). Liquefactive necrosis samples showed higher positivity than solid-change specimens for all techniques except culture (all P < 0.001). Drainage specimens yielded higher tuberculosis DNA and GeneXpert positivity than surgical resection specimens. Combining surgical and drainage specimens increased culture positivity to 26.09%. CONCLUSION: Etiological positivity rates in cervical lymph node tuberculosis correlate with pathological features. Maximizing liquefactive necrosis sampling for the GeneXpert assay and combining different sampling techniques (such as, surgical resection, incision and drainage, needle biopsy) for etiological detection enhances diagnostic accuracy.