Imaging for malignant pleural effusions—still no routine role of positron emission tomography

Malignant pleural effusions (MPEs) are a common diagnostic challenge for the respiratory physician. Their incidence is increasing with an estimated 150,000 new cases in the USA annually (1). As well as an increasing incidence, patients with MPE are presenting older due to ageing population and improved survival from primary cancer. The survival from diagnosis of all-cause MPEs is poor at around 5 months (2). Therefore, a clear and minimally invasive pathway for investigating these patients is essential. Currently, the mainstay of early investigation is computed tomography (CT) scanning and pleural fluid sampling for cytological analysis.