Pleural effusion in patients with non-Hodgkin's lymphoma: a case-controlled study

Pleural effusion is reported in up to 20% of patients with non-Hodgkin's lymphoma (NHL), most often at presentation. However, the prognostic implications of such findings are not clear. The majority of the information in the literature is based on minor observational studies or case reports. Therefore, a case-controlled study was performed to verify the clinical significance of pleural effusion in NHL.

Seventeen patients with pleural effusion at the time of presentation of NHL were identified. They were categorized by grade of NHL (based on the Working Formulation). Twenty-nine control patients with similar histopathologic characteristics who had Stage III/IV NHL without pleural effusion were matched to these cases by age, time of diagnosis, and treatment.

Ten patients with intermediate grade NHL were matched with 23 controls. No statistically significant difference in complete remission or survival rates between these groups was found (P=0.69 and P=0.7, respectively). The remission and survival rates also were similar in the subgroup of patients and controls who were treated with aggressive chemotherapy. Similarly, no difference was found in these parameters between four cases and six matched controls with low grade lymphoma. No matched controls were found for the patients with high grade lymphoma, but these patients had an unfavorable outcome. Fourteen of the 17 studied patients had an exudative type of pleural effusion. Thoracentesis yielded a positive cytologic finding in every case.

The presence of pleural effusion at the time of presentation of NHL does not adversely affect complete remission or survival rates.