Diagnostic Value of EBUS-TBNA for Lung Cancer with Non-Enlarged Lymph Nodes: A Study in a Tuberculosis-Endemic Country

BACKGROUND: In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET. METHODS: We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET. CONCLUSION: In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred

Hereditary defect of hepatobiliary cysteinyl leukotriene elimination in mutant rats with defective hepatic anion excretion

Hepatobiliary and renal elimination of cysteinyl leukotrienes were investigated in a mutant rat strain with a hereditary defect in the hepatobiliary excretion of conjugated bilirubin, dibromosulfophthalein and ouabain. After intravenous injection of [3H]leukotriene C4, the initial half-life of radioactivity circulating in blood was 79 +/- 15 sec (S.D.) in transport mutant rats as compared to 31 +/- 6 sec (S.D.) in normal Wistar rats. The intrahepatic leukotriene radioactivity was increased 5-fold after 1 hr in mutant rats, while the biliary elimination of [3H]leukotrienes was reduced to 1.8% of control. In normal rats, 77 +/- 7% (S.D.) of the administered leukotriene radioactivity were recovered in bile within 1 hr. The total recovery of radioactivity from bile, urine, liver, intestine, stomach, kidneys, muscular system and blood 1 hr after intravenous [3H]leukotriene C4 was 89 +/- 6% (S.D.) in normal rats and 46 +/- 4% (S.D.) in transport mutants. Enterohepatic circulation was studied after intraduodenal administration of N-acetyl-[3H]leukotriene E4, a major cysteinyl leukotriene metabolite in rat bile. In transport mutants, hepatobiliary elimination of the intestinally absorbed [3H]leukotriene was reduced to 5%, whereas urinary excretion was not significantly affected. [3H]Leukotriene metabolites in bile, liver and urine were separated by reversed-phase high-performance liquid chromatography. The proportion of N-acetyl-[3H]leukotriene E4 relative to polar leukotriene metabolites was higher in the bile of transport mutants as compared to control Wistar rats when analyzed within 30 to 60 min after intravenous injection of [3H]leukotriene C4.(ABSTRACT TRUNCATED AT 250 WORDS