A pelvic kidney is a kidney that is seen fixed in the bony pelvis or across the spine.  These patients are asymptomatic. Renal tract pathology (e.g. infection, calculus) can affect pelvic kidneys and thus the referred pain is not typical for the renal tract and it may be confused for appendicitis or pelvic inflammatory disease.  http://radiopaedia.org/articles/pelvic-kidney