Rare Causes of Hydronephrosis in Adults and Diagnosis Algorithm: Analysis of 100 Cases During 15 Years

Introduction Hydronephrosis (HN) is a common pathology that is with/without obstruction. HN should be promptly addressed; otherwise, it progresses to cause impaired kidney function. This study was conducted to define the diagnosis algorithm and poor prognostic parameters used to evaluate unknown HN. Materials and Methods This study enrolled 100 patients who were over 20 years of age and were admitted to the center between 2001 and 2015 for the diagnosis and treatment of HN. Although initial diagnostic tests were applied, the HN etiology of the patients could not be found in ambulatory conditions; therefore, they were hospitalized to seek the causes for their HN. Patients who had a malignancy or tuberculosis or any previous ureteral injury were excluded. Results Of these cases, 29 were on both sides, whereas 42 were on the left side. Despite further investigations, the etiology was not determined in five patients. The frequency of malignancy in patients with hematuria (5/15) was two times higher than in patients without hematuria (33% vs. 17.6%; p = 0.01). Additionally, the malignancy rate was significantly higher in patients with weight loss (100%) than those without weight loss (OR: 6.25; p < 0.001). Conclusions Further investigation is recommended to define the precise etiology of HN. Hematuria and weight loss should be considered poor predictive factors during diagnosis.