LAUSR

We thank Dr. Yorita for his interest in our article investigating the association between ureteral pseudodiverticulosis and urothelial cell carcinoma [1]. As to the question of accumulation of cases in the study, it was a retrospective review of sequential patients with ureteral pseudodiverticulosis as described on imaging reports between January 2002 and Jan 2010, as described in the methods section of the article. No pseudodiverticulum was larger than 4 mm in size. We appreciate Dr. Yorita’s literature review of pseudodiverticulosis and his distinction between true and false ureteral diverticula. The detailed clinicopathologic study on pseudodiverticulosis published by Dr. Wasserman [2] is valuable and was referenced in our original article. We agree that histologic examination of the ureters after an imaging finding of ureteral pseudodiverticulosis would be the gold standard. However, limiting the study of pseudodiverticulosis only to ureters surgically removed or evaluated at autopsy would lead to significant bias. The claim that ureteral pseudodiverticulosis should be reserved as a clinicopathologic term would seem an open question as this diagnosis is established in the imaging literature. Although a distinction between a rare true diverticulum and the more common pseudodiverticulum is not unreasonable, the acknowledged rarity of the former condition should not bias the results of an imaging association or the results of this study, particularly given the small size of the ureteral outpouchings in our study. We appreciated the reference to a “unique case” of pseudodiverticulosis diagnosed by multidetector CT [3], but given that the difference being highlighted between ureteral diverticula is a matter of histologic layers of the ureter, the spatial resolution of CT would not seem currently capable of this sort of distinction [4].