B-Cell lymphoma of the lung: epidemiology, clinical features and survival

Introduction: Lymphoid neoplasias are a heterogeneous group of hematologic malignancies arising mainly in the lymph nodes. Nevertheless, in a substantial group of patients (pts), they can primarily arise in extranodal sites or affect them secondarily, either per continuitatem or in the setting of a generalized disease. Although lymphoma research is a major focus in haematology, mainly due to the rarity of such a condition, only few is known about the epidemiology of lung involvement of B-cell malignancies as well as their outcome.

Methods: We retrospectively assessed 935 consecutive pts treated with rituximab between 1998 and 2012, affected by a B-cell non-Hodgkin lymphoma (NHL): 348 diffuse large B-cell lymphomas (DLBCL), 221 follicular lymphomas (FL), 62 mantle cell lymphomas (MCL), 124 chronic lymphocytic leukemias, 13 Richter Syndromes, 43 mucosa associated tissue NHL (MALT) or marginal zone lymphoma (MZL), 124 other lymphoma. We evaluated them regarding primary or secondary lung and/or pleura involvement. Up to now data regarding lung infiltration was gathered for all DLBCL and up to 2007 for the other NHL. We look forward to complete our dataset for the meeting.

Results: We identified 51 pts with lung and/or pleura disease (5%). Most of them were affected by DLBCL (29/348 [8%]), followed by MALT (6/21 [28%]), MCL (4/40 [10%]), FL (9/136 [7%]), and other NHL (3/57 [5%]). Overall 51 cases with lung and/or pleura involvement were recorded (24 lung, 21 pleura, 6 both). Lung and/or pleura was the primary site of disease in only 7 pts (0,74%), while a secondary lung involvement was registered in 44 cases (4.7%), either per continuitatem (1.3%) or in the setting of a generalized disease (3.4%). At time of diagnosis 43 pts (84%) had stage III/IV disease and elevated LDH was recorded in 31 cases (61%). Due to the heterogeneity of the lymphoma entities, survival analysis was only performed for the DLBCL subgroup. Five year overall survival was 50% and differed significantly among the IPI subgroups (p = 0.017), ranging from 100% to 0%. Of the single IPI factors only age > 60 years significantly influenced survival as a sole variable.

Conclusions: Lung involvement is a very rare condition in B-cell NHL, and mainly occurs in the setting of a generalized disease. The most frequent histologic subtype was DLBCL and we confirm the important prognostic role of the IPI.