Solution: This case should be entitled "When they were giants". The finding is somewhat subtle, but definitely real and should be part of your standard search pattern for an abdominal radiograph. In this case, there is definitive assymetry in the psoas margins, left larger and less distinct than right. The underlying process is essentially impossible to predict, could be a psoas abscess, a retroperitoneal hemorrhage from a ruptured aortic aneurysm, lymphoma, or what it really is, which is a mucinous cystadenocarcinoma of the psoas muscle.







Remember to have a system for reading radiographs and progress through the system. In the case of abdominal radiographs, this should include the psoas margins.