acute renal colic caused by an obstructive ureterolithiasis is in itself usually a solitary finding . we present a case of a 47-year - old male who presented with acute right lower quadrant pain and associated symptoms suggestive of both renal colic and acute appendicitis . a 47-year - old caucasian male with two previous isolated episodes of nephrolithiasis presented with a three day history of non - specific umbilical abdominal pain , migrating to the right iliac fossa with radiation to the right back . he stated having similar episodes two months and three years prior ; each time he was diagnosed with nephrolithiasis and required lithotripsy . otherwise , he reported normal bowel movements and urinary habits without nausea , vomiting , fever , chills , or sweats . ct showing thickened appendix on physical exam the patient was afebrile ( 97.2f ) with a normal pulse and blood pressure . an abdominal exam revealed right lower quadrant tenderness at mcburney s point with no rebound or guarding and a negative rovsing s sign . laboratory results revealed a white blood cell count of 10.3 x 10/l with a left shift , a bun of 31 mg / dl , and a creatinine of 1.9 mg / dl . 1a ) depicts a thickened appendix measuring > 12 mm with periappendiceal fluid suggestive of acute appendicitis . ct scan showing moderate hydronephrosis the patient elected to undergo right ureteral stent placement and laproscopic appendectomy . clinical findings remain a reliable and accurate method of diagnosing acute appendicitis ( 1 ) . the alvarado scoring system is one of such clinical diagnostic modalities to avoid the use of ct when deciding to proceed to appendectomy in such patients . however even with the use of scoring systems , the confusing picture that acute appendicitis can present at leads the clinician to choose computerized tomography for diagnosis . ct provides a higher sensitivity and specificity in diagnosis of acute appendicitis ( 5,6 ) and aids in the diagnosis of a concurrent disease process , as we have demonstrated in this case report . the overall lifetime risk of developing acute appendicitis in the united states is 8.6% and 6.7% for males and females respectively ( 7 ) . the lifetime risk of developing urolithiasis is 10% and 5% for males and females respectively within the united states ( 8) . generally , acute appendicitis and renal colic present as separate processes . we present a case where the two acute processes occur together , and are distinguished prior to surgical intervention by the use of ct .
the differential diagnosis of right lower quadrant abdominal pain includes both ureterolithiasis and acute appendicitis . 
 surgical treatment can be undergone without confirmatory imaging studies after a clinical diagnosis is made . 
 for this reason , an occult , second abdominal process may be present.a 47-year - old male presented with a three - day history of acute right lower quadrant abdominal pain . 
 a contrast ct revealed both a 6 mm calculus obstructing the right ureter and acute appendicitis . 
 the patient underwent appendectomy and ureteroscopy with stent placement at the same time.simultaneous appendicitis and ureterolithiasis may present with similar clinical findings . due to the potential risks associated with missing either diagnosis , imaging studies may be an appropriate as a step in the management of the patient with right lower quadrant pain .