Introduction

Pleural and pericardial effusions may occur in patients with advanced malignancy, or may be the presenting manifestation of malignancy. The symptoms caused by effusions can be the cause of substantial morbidity, and may limit the quality of life for patients with advanced cancer. With appropriate management, these symptoms can be minimized or eliminated. This chapter is concerned predominantly with the management of effusions in patients with pre-existing malignancy, rather than the approach to patients presenting with an undiagnosed pleural or pericardial effusion.

Pleural effusion

Up to 10 liters of fluid traverses the pleural space each day. Under normal circumstances, the rate of fluid resorption is equal to the rate of production, so there is no net change in the amount of fluid that is present (only 5–10 ml). Four factors maintain this balance. These include the hydrostatic and colloid pressures of fluid in capillaries, capillary permeability, and fluid absorption by lymphatics. Changes in any of these factors can result in accumulation of pleural fluid. Thus, in patients with malignancy, effusions may arise because of increased production (for example because of changes in capillary permeability due to tumor deposits on the pleural surface) or reduced absorption (for example due to obstruction of mediastinal lymphatics). Malignant effusions are typically exudates (protein content >3 g/100 ml).

The most common causes of pleural effusions differ between men and women (Table 62.1). Overall, combining both sexes, breast cancer, lung cancer, and lymphoma account for 75% of all malignant pleural effusions.