55-year-old female presents with abdominal pain. An axial CT scan through the upper portions of the left kidney shows distortion and compression of the upper pole calyces (yellow arrowhead) . There are bilateral “beak signs” (white arrowheads) indicating a benign slow growing cyst
Diagnosis: Left Sided Simple Renal Cyst Bosniak 1
Ashley Davidoff MD TheCommonVein.net RnD
The “Bird Beak sign” is a radiological term used in the context of imaging studies, especially CT scans, to describe the appearance of simple renal cysts. It refers to the characteristic appearance of the cyst where there is a protrusion or a linear component extending from the cyst. This extension is often seen at the juncture of the cyst with the renal hilum or at the periphery of the kidney, giving the appearance of a beak.