Characteristics of patients with myelomatous pleural effusion. A systematic review

Background: Myelomatous pleural effusion (MPE) is rare in multiple myeloma, and therefore its characteristics are not well defined.

Methods: A systematic review (4 online databases) was conducted of articles describing the clinical characteristics of patients with MPE, pleural effusion's biochemical characteristics and treatment efficacy. We analysed isolated cases and small retrospective series.

Results: We included 98 articles with a total of 153 patients with MPE. The median age was 62years, and the ratio of males to females was 1.7:1. The most common symptoms were dyspnoea (98.8%), bone pain (100%) and chest pain (95.3%), and the most relevant abnormal laboratory test results were anaemia (90.1%) and renal failure (53.8%). MPE was predominantly unilateral (63.9%) and covered more than two-thirds of the hemithorax (54.5%). The pleural fluid (PF) had a haematologic/serohaematologic appearance (87%) and met the criteria for lymphocytic (78.6%) exudate (94.7%). The most cost-effective diagnostic procedures were pleural cytology (95.9%) and the observation of a monoclonal peak in the PF (94.7%). In a significant proportion of patients (54.7%), the MPE did not respond to treatment, and the best response was achieved when chemotherapy (with/without corticosteroids) was combined with therapeutic thoracentesis, chest drainage or pleurodesis.

Conclusions: MPE predominates in middle to older age men, is symptomatic and is usually unilateral. PF is an exudate with a haemorrhagic appearance, and the most cost-effective diagnostic procedure is pleural cytology. Treatment response is unfavourable in more than half of patients.