American Board of Internal Medicine (ABIM) Certification Practice Exam

What is definitive for diagnosing Aspergillus sinusitis?

1. Tissue biopsy demonstrating hyphae and a positive culture

2. Positive serum galactomannan test only

3. Chest X-ray findings typical for Aspergillus

4. Standard culture without specific testing

The correct answer is: Tissue biopsy demonstrating hyphae and a positive culture

The definitive diagnosis of Aspergillus sinusitis is achieved through a combination of histopathological examination and microbiological culture, specifically through tissue biopsy demonstrating hyphae and a positive culture. When a tissue biopsy is obtained, the presence of septate hyphae, which are characteristic of Aspergillus species, under microscopy confirms the diagnosis. Additionally, a positive culture for Aspergillus further supports the diagnosis, as it provides direct evidence of the fungal pathogen in the affected tissue. Relying solely on a positive serum galactomannan test is not definitive for diagnosing Aspergillus sinusitis, as this test can yield false positives and does not confirm the presence of infection in sinus tissue. Similarly, chest X-ray findings typical for Aspergillus may suggest pulmonary involvement but are not sufficient on their own to diagnose sinusitis specifically. Lastly, standard cultures without specific testing may miss the organism or its identification may not meet the specificity required for a definitive diagnosis. Thus, the combination of tissue biopsy demonstrating hyphae along with a positive culture serves as the standard for establishing a conclusive diagnosis for Aspergillus sinusitis.