Phantom organ sign

The phantom organ sign is a term used when a large mass arises from a small organ and as a consequence, it is impossible to detect the affected organ.

The identification of this sign and other radiological signs such as the embedded organ sign, beak sign, and prominent feeding artery sign on CT or MRI is particularly useful in localizing masses from retroperitoneal organs. On the contrary, the absence of these signs supports the possibility of a primary retroperitoneal tumor ¹.

Some false positive of the phantom organ sign has been reported such as the case of huge retroperitoneal sarcomas involving the adrenal glands ¹.