Management of malignant pleural effusions

Abstract

Malignant pleural effusion is diagnosed when exfoliated malignant cells are found in pleural fluid or when pleural tissue is invaded by malignant cells. Malignancy is one of the most common causes of exudative pleural effusions. In postmortem examinations of patients who died of cancer, the incidence of malignant effusion was 16% [1]. Carcinoma of any organ can metastasize to the pleura. However, lung cancer is the most common cause of malignant effusions with an incidence of 40%. When first evaluated, approximately 15% of that group of patients exhibited pleural effusion and up to 50% of the patients with an advanced disease may acquire a pleural effusion during the course of their disease [2-4]. Breast cancer is the second cause with an incidence of 25%. Lymphomas account for 10% of all malignant effusions and are the most common cause of chylothorax. Other solid tumors, such as ovarian and gastric cancer, represent the 5% or less of malignant pleural effusions while in 3-10% of patients the effusion is due to malignancy of unknown origin [5]. The incidence of mesothelioma varies according to the geographic location.