Which condition is most likely indicated by RLQ pain with extension of the right thigh?

The presence of right lower quadrant (RLQ) pain with extension of the right thigh is highly indicative of appendicitis. This specific pain response occurs due to the irritation of the psoas muscle as it is engaged during thigh extension, which is also known as the psoas sign. In appendicitis, inflammation can lead to irritation of nearby structures, including the iliopsoas muscle, thereby eliciting pain during certain movements, such as extending the thigh.

The clinical presentation of appendicitis often includes classic symptoms such as abdominal pain that starts in the periumbilical area and subsequently localizes to the RLQ. Additionally, the presence of rebound tenderness or guarding can further support a diagnosis of appendicitis.

In contrast, while conditions like cholecystitis, ectopic pregnancy, and ovarian torsion may also cause abdominal pain, they tend to present with distinct symptoms and are less likely to relate specifically to thigh movement. Cholecystitis pain typically manifests in the right upper quadrant, ectopic pregnancy may present with unilateral pain and signs of potential internal bleeding, and ovarian torsion is typically associated with unilateral adnexal pain, often with nausea or vomiting. Thus, the specific symptom of RLQ pain