FIG 57.13 Chest radiograph in anteroposterior view from an adolescent boy with absent pericardium Cardiomegaly with inconspicuous right heart border is evident Lung tissue (arrow) is interposed in prominent space between aorta and main pulmonary artery The left heart border is straight and elongated (Snoopy sign) Pericardial Cysts Congenital pericardial cysts are rare and result from failure of fetal lacunae to coalesce with the pericardial coelom.130 Uncommonly, these cysts may be inflammatory or posttraumatic In most instances, the patient is asymptomatic and cysts are incidentally detected on chest x-ray or CT scan Rarely, infection of the cyst or bronchial compression may cause chest pain and dyspnea.131,132 Small cysts may evade detection on routine echocardiography The presence of echo-free space adjacent to the heart on echocardiography should raise suspicion of pericardial cyst MRI provides diagnostic confirmation No treatment is required for an asymptomatic pericardial cyst Those with infection and bronchial compression require surgical excision Acknowledgments I am indebted to the late Dr Rajnish Juneja, Professor of Cardiology, All India Institute of Medical Sciences, New Delhi, for providing insights in the management of bacterial pericarditis I am also grateful to Dr Sandeep Singh, Professor of Cardiology, All India Institute of Medical Sciences, New Delhi, for critical review of the manuscript Annotated References Imazio M, Brucato A, Cemin R, et al ICAP investigators A randomized trial of colchicine for acute pericarditis N Engl J Med 2013;369:1522–1528 Imazio M, Bobbio M, Cecchi E, et al COlchicine in addition to conventional therapy for acute PEricarditis: results of the COlchicine for acute PEricarditis (COPE) trial Circulation 2005;112:2012–2016 Imazio M, Brucato A, Cemin R, et al For the CORP (Colchicine for Recurrent Pericarditis) investigators Colchicine for recurrent pericarditis (CORP): a randomised trial Ann Intern Med 2011;155:409–414 Imazio M, Belli R, Brucato A, et al Efficacy and safety of colchicine for treatment of multiple recurrences of pericarditis (CORP-2): a multicentre, double blind, placebo-controlled, randomised trial Lancet 2014;383:2232–2237 These randomized controlled trials established the role of colchicine in acute and recurrent pericarditis in adults Raatika M, Pelkonen PM, Karjalainen J, Jokinen EV Recurrent pericarditis in children and ... Rajnish Juneja, Professor of Cardiology, All India Institute of Medical Sciences, New Delhi, for providing insights in the management of bacterial pericarditis I am also grateful to Dr Sandeep Singh, Professor of Cardiology, All India Institute of Medical Sciences, New Delhi, for