原发性非梗阻性巨输尿管症是指在膀胱及膀胱三角无异常、尿路无梗阻的情况下出现的输尿管扩张。其特征为盆腔段输尿管明显扩张。临床少见。现报导1例经尿路造影及病理证实的病例。女性，41岁，X钱号25248，病理号2039。4年来在无明显诱因情况下出现腰背部酸胀感，无发热，无尿 Primary non-obstructive megaureter refers to the ureter in the absence of bladder and bladder trigones without obstruction. It is characterized by significant expansion of the pelvic ureter. Clinical rare. Is reported in 1 cases by urography and pathology confirmed cases. Female, 41 years old, X money number 25248, pathology number 2039. 4 years in the absence of obvious incentives appear lower back soreness, no fever, no urine