Grey-Turner’s sign simply refers to the bluish discoloration of the flanks. The interesting thing about this sign is that whenever this sign is found, medical students are alerted to the fact that there is a possible underlying retroperitoneal bleeding going on. Obviously, this sign could also indicate a possible intraperitoneal bleed besides the possibility of retroperitoneal bleed. The source of bleed could be traumatic or non-traumatic, as in hemorrhagic pancreatitis.
However, when British surgeon George Grey Turner (1877-1951) first described it in 1920, in the British Journal of Surgery, it was described as a sign of hemorrhagic pancreatitis.
Not many know about the pathophysiologic basis of this sign, however. It is actually due to the action on the abdominal wall and skin of leaking extravasated pancreatic juice from the hemorrhagic or necrotizing pancreatitis tracked subcutaneously. It could also be the blood collection tracked subcutaneously from retroperitoneal organs in the flank region.
In this picture, CT scan was done; showing no evidence of retroperitoneal or intraperitoneal bleed. This patient had an intramuscular bleeding resulting in the bruise. Does this considered as a Grey Turner sign? But how do we know conclusively whether retroperitoneal bleed has actually occurred without performing a CT scan? Isn't Grey-Turner sign a clinical sign?
Grey-Turner sign can be accompanied by another sign, the Cullen sign; also of similar pathophysiologic basis but at a different location. Grey-Turner refers to bruising at the flank; Cullen sign refers to bruising at the periumbilical region.
Grey-Turner vs Cullen: How to remember which is which?
The way I remember which is Grey-Turner and which is Cullen:
C = Cullen = Central abdomen (periumbilical)
Grey-Turner is the other one, then ("periphery", flank)