Management of pleural effusion in the cancer patient

The differential diagnosis of a pleural effusion is expanded in the cancer patient. A cancer patient may have a malignant pleural effusion, a pleural effusion indirectly caused by the cancer or its treatment, or a pleural effusion unrelated to the cancer. The approach to the cancer patient with a pleural effusion must take into account the impact of the pleural effusion on quality of life, type and stage of the underlying cancer, impact of biopsy procedures on cancer staging, availability of treatment of the underlying cancer, performance status, and patient preferences. Minimally invasive palliative treatment options for the management of symptomatic malignant pleural effusion, such as chronic indwelling pleural catheters, have not only changed the treatment of the effusion but also require a reassessment of what constitutes an adequate diagnostic evaluation prior to considering such treatment options. Of particular concern to the clinician is the cytologically negative exudative pleural effusion for which a cause could not be established after the initial diagnostic evaluation. The decision to proceed to more invasive diagnostic testing must be individualized and the clinician must consider the limitations of histopathological examination of tissue obtained by invasive procedures.