Malignant pleural effusion of multiple myeloma: prognostic factors and outcome.

Malignant pleural effusion (MPE) in multiple myeloma (MM) is rare. Approximately 80 cases have been reported. To delineate optimal treatment and prognostic variables in these patients, we reviewed 11 MM patients with MPE. MPE developed at median of 12 months from diagnosis of MM. All the patients had high-risk disease based on complex karyotypic abnormalities including deletions of chromosome-13 (n=9), elevated beta-2 microglobulin (B2M) (n=9), high C-reactive protein (CRP) (n=8), high plasma cell labeling index (n=5) or high LDH (n=5). A significant increase in B2M, LDH, and CRP was observed at the onset of MPE. The initial diagnosis of MPE was based on positive cytology (n=9), pleural fluid cIg/DNA (n=9) or pleural fluid cytogenetics (n=4). Pleural tissue infiltration was found on pleural biopsy and autopsy in one patient each. Systemic chemotherapy comprising dexamethasone, cyclophosphamide, etoposide and cisplatin (DCEP) (n=7) and pleurodesis (n=7) were effective in resolving MPE but survival was short. High dose chemotherapy with peripheral blood stem cell support for MPE in six patients conferred no clear survival advantage. These patients died at median of four months from onset of MPE. Patients with bone marrow complex karyotypic abnormalities including deletion-13 (n=9) had a shorter (median--18 months) overall survival compared to patients with normal cytogenetics (median--38 months). MPE in patients with MM is often associated with high-risk disease including deletion 13 chromosomal abnormality and heralds a poor prognosis despite aggressive local and systemic treatment.