Clinical features and outcomes of pulmonary lymphoma: A single center experience of 180 cases

Background: Pulmonary lymphoma arises primarily from the lung, which is extremely rare, or be secondarily involved by lymphoma. The clinical features, management, and prognostic factors have not been clearly identified. Methods: Sixty-three patients with primary pulmonary lymphoma (PPL) and 117 patients with secondary pulmonary lymphoma (SPL) treated in our institution between June 2003 and December 2017 were retrospectively reviewed. Results: MALT (67%) was the most common pathological subtype of PPL, while DLBCL (48%) was the most common subtype of SPL. Compared to the patients with PPL, the presence of B symptoms, advanced disease stage, intermediate-high or high risks of IPI and NCCN-IPI, elevated inflammatory parameters, and elevated cytokine levels were all observed in patients with SPL. Consolidation was the most frequent radiological finding in PPL cases, while nodules were the most frequent finding in SPL. With a median follow-up of 35 months (range 2-176), the estimated 3-year OS rates were 95%, 100%, 70% and 50% in indolent PPL, indolent SPL, aggressive PPL, and aggressive SPL, respectively. In indolent pulmonary lymphoma, none of the prognostic factors we studied significantly influenced survival of the patients. In aggressive pulmonary lymphoma, univariate analysis showed that NCCN-IPI was related to OS in PPL. Multivariate analysis showed that beta 2-MG was an independent prognostic factor for OS in SPL. Conclusions: Primary and secondary pulmonary lymphoma differ in their clinical features and outcome. Furthermore, beta 2-MG is the independent prognostic factor for OS in patients with aggressive SPL.