Clarissa B. Smith

Background: Electromagnetic navigation bronchoscopy (ENB) utilizes three-dimensional reconstructions based on computed tomography to guide the biopsy of pulmonary lesions. Various limitations have been described; however, supporting data have been limited by small sample sizes. Methods: Cases of ENB for evaluation of a pulmonary lesion at a single institution during a 1-year span were reviewed for demographics, lesion location, procedural details, and final tissue diagnosis. ENB was performed by 3 pulmonologists using the Veran platform with rapid on-site evaluation. T test or Mann-Whitney U test compared continuous variables and χ² or Fisher exact test compared categorical variables as appropriate. A patient with a negative or inconclusive biopsy was followed for 1 year postprocedure. Results: A total of 107 pulmonary lesions were evaluated. The population studied had a mean age of 67 and a median pulmonary lesion size of 26.0 mm. For malignant lesions, the pathologic diagnostic yield from ENB was 52.1% (37/71). The diagnostic yield of benign lesions was much lower at 16.7% (6/36). The overall procedural complication rate was 8.4% (9/107). Complications were more likely to occur in patients with malignant lesions. The most common complication was pneumothorax, occurring in 5.6% of all biopsies and 7.0% of patients with malignant lesions. Conclusion: This study demonstrates significant differences in diagnostic accuracy between lesions found to be malignant versus benign. Our observed complication rate was slightly higher than other groups have reported, with a greater frequency occurring in patients with malignant lesions; however, the rate of pneumothorax was still lower than computed tomography–guided transcutaneous biopsies.

Pulmonary infections due to Aspergillus, Mucorales, and Nocardia have high morbidity and mortality, in part due to diagnostic challenges. Commercially available molecular assays on bronchoalveolar lavage fluid (BALF) may have increased sensitivity over currently available diagnostic options. Our aim was to characterize the diagnostic performance of assays for each of these pathogens in our patient population. The medical records of patients whose BALF was tested by polymerase chain reaction (PCR) for Aspergillus, Mucorales, and Nocardia between 2019 and 2021 were reviewed in a cross-sectional manner. European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG) definitions of “proven,” “probable,” and “possible” infection were used, including histopathology, serology, and culture. We used (1) “proven” or “probable” infection by EORTC criteria, (2) improvement or stabilization on targeted antimicrobial therapy, and (3) absence of a more likely diagnosis as the reference standard. The Aspergillus PCR assay demonstrated the highest agreement with the diagnostic reference standard, with 31.25% (10/32) sensitivity and 97.17% (206/212) specificity. Positive and negative predictive values were 62.50% (10/16) and 90.35% (206/228), respectively. No Mucorales or Nocardia infections were identified by the diagnostic reference standard, so the sensitivity could not be calculated. The specificity of Mucorales and Nocardia targets was 98.35% and 96.69%, respectively. Our data demonstrated relatively poor clinical sensitivity for all 3 constituent PCR assays in our patient population, suggesting a limited role for this test in the diagnosis of Aspergillus, Mucorales, or Nocardia.

Acanthamoeba species are free-living protozoa found pervasively in water and soil, which can cause infections of the central nervous system, skin, and eye. Amoebic keratitis (AK) is a vision-threatening, often chronic infection that is associated with the use of soft contact lenses due to corneal microtrauma and improper cleaning and storage. Although AK infections are rare, they cause significant morbidity including vision loss due to the diagnostic and therapeutic challenges they pose. The clinical course is determined by the organism’s inherent pathogenicity, delay of diagnosis, and the paucity of data on effective therapeutic regimens. The case series and review of literature that follows examine current latest best practices in AK diagnosis including in vivo confocal microscopy (IVCM) and therapeutic interventions including miltefosine.

Endemic mycoses including Histoplasma, Blastomyces, Coccidioides, Paracoccidioides, and Talaromyces are dimorphic fungi that can cause a variety of clinical manifestations, including respiratory infections. Their pulmonary presentations are variable, and diagnosis is often delayed as they can mimic other infectious and non-infectious causes of pulmonary disease. Delay in diagnosis can lead to unnecessary antibiotic use, repeat hospitalizations, and increased morbidity and mortality. The diagnosis of endemic fungal pulmonary infections often relies on multiple diagnostic tests including culture, tissue histopathology, antigen assays, and antibody assays. Due to the increased use of immunosuppressive agents and the widening geographic ranges where these infections are being found, the prevalence of endemic fungal infections is increasing. Physicians need to be aware of the clinical manifestations of pulmonary infections due to endemic fungal in order to ensure that the proper diagnostic work up is obtained promptly. A high index of suspicion is particularly important in patients with suspected pulmonary infections who have failed to improve despite antibiotics in the appropriate setting. We present a review diagnostic testing for pulmonary infections due to endemic mycoses.