First detection of SARS-CoV-2 by real-time reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay in pleural fluid

COVID-19 is a pandemic infection due to a novel coronavirus (SARS-CoV-2) spreading, resulting in a wide range of clinical features, from asyntomatic carriers to acute respiratory distress syndrome. The gold standard for diagnosis is nucleic acid detection by real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) in naso-pharyngeal swabs, but, due to limitations in its sensitivity, thoracic imaging plays a crucial, complementary role in diagnostic work-up and it allows also to reveal atypical findings and potential alternative target for sampling, such as pleural effusion. Although not common, pleural involvement has been described in a minority of patients. Here, we describe the first case of SARS-CoV-2 RT-PCR detection in pleural fluid obtained by means of ultrasound-guided thoracentesis and report its main characteristics. Pleural effusion is not a common finding in COVID-19 infection, but a prompt recognition of this potential localization may be useful to optimize diagnostic work-up as well as management of these patients.