Pelvic ectopic kidney with acute pyelonephritis: wolf in sheep's clothing.

The differential diagnosis of right lower quadrate pain at the emergency department is quite perplexing. We describe a 38-year-old woman presenting with characteristic clinical and laboratory features of ruptured appendicitis with severe sepsis. However, contrast-enhanced computed tomography scan of the abdomen established the diagnosis of pelvic ectopic kidney with acute pyelonephritis. Antibiotic treatment eventually achieved satisfactory resolution without compromise of renal function. It is should be addressed that, even with the advent of modern imaging modalities, there can be a diagnostic pitfall in general practice when managing right lower quadrate pain in patients with typical presentations of acute appendicitis without sonographic evidence, as illustrated in this case. In conclusion, early recognition using exquisite imaging studies with raised awareness in the clinical setting and prompt antibiotic treatment can avoid unnecessary intervention, preserve renal function, and prevent a life-threatening catastrophe.