RT Journal Article SR Electronic T1 Spontaneous haemopericardium due to vitamin K deficiency in an adult patient with cardiofaciocutaneous syndrome JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e252047 DO 10.1136/bcr-2022-252047 VO 15 IS 12 A1 Tasos, Emmanuel A1 Elliott, Elizabeth A1 Sharip, Mohammed Tauseef A1 Massey, Dunecan YR 2022 UL http://casereports.bmj.com/content/15/12/e252047.abstract AB We present the case of an adult man with cardiofaciocutaneous syndrome, who initially presented to the emergency department with severe abdominal pain and distension, but was diagnosed with cardiac tamponade on CT after distended neck veins and tachycardia were identified on examination. He had emergency pericardial drainage to relieve the haemopericardium and was treated with colchicine. He was further found to be deficient in factors II, VII and X despite not being on warfarin, and was therefore supplemented with vitamin K. This confirms a diagnosis of vitamin K deficiency, likely multifactorial from malabsorption due to chronic intestinal pseudo-obstruction, small bowel obstruction and possibly exacerbated by subsequent ciprofloxacin use for small intestine bacterial overgrowth. This is the first report of spontaneous haemopericardium secondary to vitamin K deficiency in an adult patient not on anticoagulation, and is an important learning point due to the life-threatening progression of the haemopericardium and cardiac tamponade.