Posterior mediastinal "pseudo-mass" of the newborn.
D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008479:Mediastinal Neoplasms / Q000151:congenital / Q000000981:diagnostic imaging*; D011859:Radiography