Which condition is often characterized by flank bruising?

Flank bruising is a clinical sign associated with Grey Turner sign, which typically indicates retroperitoneal hemorrhage or bleeding occurring in the abdominal cavity, often due to conditions such as pancreatitis or abdominal trauma. The appearance of bruising around the flank area can suggest that blood is escaping from the abdominal organs into the surrounding spaces, leading to discoloration of the skin due to the underlying bleeding.

In contrast, acute pancreatitis, appendicitis, and cholecystitis generally present with different symptoms and signs that are not associated with flank bruising. Acute pancreatitis may cause severe abdominal pain and tenderness but does not typically cause flank bruising. Appendicitis primarily affects the lower right abdomen, and cholecystitis generally presents with right upper quadrant pain, often accompanied by other gastrointestinal symptoms, but does not usually lead to bruising. Therefore, the presence of flank bruising specifically points to Grey Turner sign as the correct answer.