Periappendicitis presenting as left renal colic.

Periappendicitis, a variant of appendicitis, is histologically diagnosed in only about 5% of appendices removed for presumptive acute appendicitis. We herein describe a boy with periappendicitis whose clinical presentation was that of left renal colic and partial left midureteral obstruction. Appendicitis not infrequently simulates right ureteral colic. However, to our knowledge appendiceal inflammation never has been reported to stimulate left ureteral colic. Also, complications of appendicitis are known to cause right ureteral obstruction (rarely bilateral) but have not been reported to cause solitary left ureteral obstruction. We found no previously reported case of solitary left ureteral obstruction from appendiceal inflammation or of periappendicitis causing a serious urologic complication.