Atypical Cells on Transbronchial Biopsies of Peripheral Pulmonary Lesions: How Should We Interpret the Result?

ABSTRACT

SESSION TITLE Lung Nodule Biopsy Yield and Accuracy SESSION TYPE Original Investigations PRESENTED ON 10/16/2022 1030 am - 1130 am PURPOSE: Atypia is common on biopsy specimens of peripheral pulmonary lesions (PPLs) and may result from inflammation or inadequate sampling of a malignancy. The significance of atypical cells on PPLs biopsies has not been well described. In addition, recent studies of navigational bronchoscopy have variably considered atypia on biopsies as diagnostic. METHOD(S) We analyzed a prospective database of consecutive PPLs sampled via navigational bronchoscopy at our institution (IRB 212187). Search terms "atypia" and "atypical" were applied to pathology reports generated by these procedures. Manual inspection ensured atypia was present in the PPL itself. Definitive PPL diagnosis was established during a two-year routine clinical follow-up. Bronchoscopy diagnostic yield was defined as histopathological findings which readily explained a nodule (malignancy, organizing pneumonia, frank purulence, granulomatous inflammation) and permitted management of the patient without an immediate additional diagnostic intervention. Atypia was considered nonspecific and, therefore, nondiagnostic. RESULT(S) From 11/2017 to 4/2019, 461 biopsied PPLs were identified. Eleven cases, none exhibited atypia, lacked complete two-year follow-up, and were excluded. Ultimately, 274 of 450 (61%) analyzed PPLs were malignant. Diagnostic biopsies were obtained in 331 (73.5%) cases. Atypical cells were present in 33 PPLs (7% of overall cohort, 28% of the 119 nondiagnostic cases). Two-thirds (22 of 33) were eventually determined to be malignant. Lung adenocarcinoma was the most common ultimate malignant diagnosis (10 cases). Most benign PPLs with atypia regressed on follow-up imaging without further pathological data (5 cases). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of atypia for an eventual diagnosis of malignancy among the 223 PPLs not diagnosed as malignant at index bronchoscopy were 46% (95% CI 31-61%), 94% (89-97%), 92% (85-96%), and 53% (46-60%), respectively, with positive likelihood ratio (+LR) of 7.3 (3.8-14). CONCLUSION(S) The presence of atypical cells was a common finding, found in 28% of PPLs without a specific diagnosis after bronchoscopy. Two-thirds of PPLs with atypia were ultimately malignant, with a high PPV (92%) for malignant diagnosis in this cohort with an overall prevalence of malignancy of 61%. CLINICAL IMPLICATIONS Atypia not diagnostic of malignancy in bronchoscopic biopsy specimens is a nonspecific finding, which may be due to inadequate sampling of a malignant PPL or inflammation. However, the high PPV and +LR of atypia for ultimate malignant PPL diagnosis suggest that in populations with a similar prevalence of malignancy and/or in the clinical context of a high pre-test probability of malignancy, atypical findings might prompt repeat biopsy or definitive PPL management (resection or ablation). DISCLOSURES No relevant relationships by Robert Lentz No relevant relationships by Kaele Leonard No relevant relationships by See-Wei Low PI ofan investigator-initiated study relationship with Medtronic Please note >$100000 by Fabien Maldonado, value=Grant/Research Support PI on investigator-initiated relationship with Erbe Please note $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Consulting relationship with Medtronic Please note $5001 - $20000 by Fabien Maldonado, value=Honoraria co-I industry-sponsored trial relationship with Lung Therapeutics Please note $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Board of director member relationship with AABIP Please note $1-$1000 by Fabien Maldonado, value=Travel Consultant relationship with Medtronic/Covidien Please note $1001 - $5000 by Otis Rickman, value=Consulting fee No relevant relationships by Briana Swanner Copyright © 2022 American College of Chest Physicians