The yield and impact of pulmonologist-performed EUS-B-FNA of subdiaphragmatic lesions-an institutional experience.

Introduction: Pulmonologists can biopsy structures below the diaphragm using the convex curvilinear ultrasound bronchoscope via the esophagus (EUS-B). The literature with respect to the value of EUS-B, rapid on-site evaluation, and final diagnostic yield for structures below the diaphragm is limited. We review our institutional experience.

Materials And Methods: Our database was queried retrospectively for EUS-B fine needle aspirations (FNAs) from 2013 to 2021. All procedures involving EUS-B-FNA of subdiaphragmatic structures were selected for analysis. The following data elements were collected for each patient: age, gender, clinical indication, sample site, on-site adequacy (OSA), preliminary and final diagnoses, and sufficiency of cell block for ancillary studies.

Results: A total of 75 subdiaphragmatic sites were biopsied in 74 patients. Of which, 87% of samples subjected to rapid on-site evaluation were deemed to contain adequate material (OSA+). There were no false-positive OSAs. Six cases remained nondiagnostic at the final diagnosis. The final diagnostic yield (with cell block) was 92% (69/75 cases). Cell block was sufficient for immunohistochemistry or special stains in all applicable cases (n = 36). Molecular testing was requested for 11 cases and successful in 10 (91%). Sampling of subdiaphragmatic sites changed the stage in 67% (38/57) of lung cancer patients.

Conclusions: Pulmonologists can perform EUS-B-FNA of subdiaphragmatic sites with high OSA and final diagnostic yield when assisted by cytopathologists. Strong correlations exist between OSA, cell block adequacy, and subsequent capacity to perform ancillary testing. EUS-B below the diaphragm can make an important contribution to the diagnosis of lung cancer, nonpulmonary malignancies, and other diseases.