A rare presentation of an ectopic kidney with pyelonephritis mimicking appendicitis.

Acute appendicitis is one of the top differential diagnoses of right lower quadrant pain in the emergency department. There are many other conditions that may mimic appendicitis such as diverticulitis, colitis and gynecological conditions. We report a rare diagnosis of a patient who presents with characteristic clinical and laboratory features of appendicitis with severe sepsis, but later showed acute pyelonephritis of a malrotated right ectopic kidney on computer tomography. An ectopic kidney is very rare with an incidence of 1 in 3000. It is usually asymptomatic, although it may also associate with obstruction, infection and urolithiasis. This case report raises the importance of early recognition of the correct diagnosis using imaging in appropriate clinical settings, and prompt antibiotic treatment can avoid unnecessary surgical intervention, preserve renal function and prevent a life-threatening catastrophe.