Unexpected Neoplasms in Lungs Explanted From Lung Transplant Recipients: A Single-Center Experience and Review of Literature

Abstract Introduction Lung transplantation is a common treatment for various indications, but undiagnosed neoplasms are found in 0.5% to 2.4% of explanted lungs. We report the largest single-institution series of patients with unexpected neoplasms in explanted lungs and compare rates of undiagnosed malignancies before and after the 2005 Lung Allocation Score (LAS) update. Methods We reviewed the medical records of patients who underwent lung transplantation at the Cleveland Clinic from 1990 to 2014. In cases of neoplasm discovered on explant, tumor type, pathological stage, recurrence, and date of death were recorded. Results From January 1, 1990 to June 30, 2014, 1303 patients underwent lung transplantation at the Cleveland Clinic. The overall mean smoking history was 35 pack-years, and 25 undiagnosed lung malignancies were found upon explant in 24 transplant recipients (1.84%). In the post-LAS era (ie, 2005 onward), 20/812 lung transplant recipients had 21 incidental neoplasms in their explanted lungs (2.5%). Seventeen of these 25 tumors occurred in patients with interstitial lung disease; 8 occurred in patients with centrilobular emphysema. Eight tumors recurred (6 in patients with interstitial lung disease and 2 in patients with emphysema). The most common histological tumor types were adenocarcinomas (n = 14) and squamous cell carcinomas (n = 7). Conclusions Unexpected neoplasms were found in 1.84% of lung transplant recipients' explanted lungs, with a slightly higher incidence (2.46%) in the post-LAS era. Neoplasms were more common in patients with interstitial lung diseases than in patients with centrilobular emphysema. Explanted lungs should be pathologically examined for evidence of tumor foci because this can impact post-transplantation management.