RT Journal Article SR Electronic T1 Diaphragmatic eventration unusual presentation: a novel thoracoabdominal compartment syndrome case JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e229475 DO 10.1136/bcr-2019-229475 VO 12 IS 6 A1 Abdulaziz Shaher A1 Abdulrahman Mohmmed Alqahtani A1 Khalid N Sinnah A1 Shaher Mousa Al Bakheet YR 2019 UL http://casereports.bmj.com/content/12/6/e229475.abstract AB Diaphragmatic eventration is a rare entity in the adult population, and usually asymptomatic1; our case is a young man with severe right-sided diaphragmatic eventration with huge dilated colon that has compromised the right hemithorax and caused complete lung collapse and mediastinal shift similar to tension pneumothorax picture with haemodynamic alteration. A single similar case report had been published but did not shed the light on the accurate description of the pathophysiological mechanism of the disease. We believe that such a high abdominal pressure that has transmitted to the thoracic cavity due to the pliable diaphragm causing such a derangment in both the anatomy and the physiology deserves reporting and we think that the term ‘thoracoabdominal compartment syndrome’ describes it accurately, so we discuss some learning points from our case and things that could have been done better.