Insufficient Diagnostic Value of Serum Galactomannan and (1,3)-β-D-Glucan in Paranasal Sinus Fungus Balls

Background and Objectives The serum galactomannan test (GM test) and the (1,3)-β-D-glucan test (G test) are utilized in diagnosing invasive fungal sinusitis. However, their effectiveness in detecting paranasal sinus fungus balls (FBs) has not been established. This study aimed to explore their diagnostic value in patients with FBs. Methods We retrospectively reviewed the medical records of 105 patients (42 with FBs and 63 with chronic rhinosinusitis [CRS]) who underwent serum GM and G tests between June 2020 and May 2021. Olfactory test results and demographics were also analyzed. Results There were 42 FB patients (10 men, 32 women) and 63 CRS patients (27 men, 36 women). The positivity rates for serum GM (7.1% in the FB group vs. 3.2% in the CRS group, p=0.640) and G test (9.5% in the FB group vs. 11.1% in the CRS group, p=0.482) did not differ significantly between groups. The sensitivities of the GM and G tests were 7.1% and 9.5%, respectively, and their specificities were 96.8% and 88.9%, respectively. The positive predictive values were 60.0% for the GM test and 36.3% for the G test, and the negative predictive values were 61.0% for the GM test and 59.6% for the G test. Conclusion Serum GM and G tests demonstrated low sensitivity and high specificity, indicating limited effectiveness in differentiating between patients with FBs and those with CRS. Histological examination remains the gold standard for the definitive diagnosis of FBs.