Is eosinophilic ureteritis an entity? 2 case reports and review

The characteristics of eosinophilic ureteritis and idiopathic segmental ureteritis are sufficiently overlapping and so uncommonly reported as to raise a nosological issue. In an attempt to address that question, we compared 2 new cases and 8 previous reports of eosinophilic ureteritis with a series of 21 idiopathic segmental ureteritis patients. One of our patients also had renal pelvic involvement, while 1 is the youngest (3 years old) patient reported and the first instance of bilateral eosinophilic ureteritis. Our review found that eosinophilic ureteritis largely occurs in atopic or hypereosinophilic syndromes, often with a traumatic history. Eosinophilic and idiopathic segmental ureteritis causes ureteral obstruction due to mural involvement. However, eosinophilic ureteritis never forms an intraluminal mass and is not associated with mucosal ulceration. In addition, we found no case reported with features that bridge the 2 conditions. We conclude that the clinical and pathological features of eosinophilic and idiopathic segmental ureteritis are sufficiently distinct to separate the 2 conditions.