We report on a 31-year-old male patient with non-invasive papillary urothelial carcinoma, low grade of the renal pelvis disguised as xanthogranulomatous pyelonephritis. The only symptom of the patient was lower back pain. The initial renal-enhanced computed tomography, magnetic resonance imaging and contrast-enhanced ultrasonography showed that the right kidney had a benign lesion and this inflammatory lesion might be xanthogranulomatous pyelonephritis. A percutaneous renal biopsy was performed and histopathologic examination revealed a xanthogranulomatous pyelonephritis. Initially, we diagnosed it as xanthogranulomatous pyelonephritis and treated it with antibiotics. One and a half years later, the patient suffered from back pain again. The lesion increased significantly and a right renal pelvic lesion with retroperitoneal lymphadenopathy was considered a malignant lesion on computed tomography scan. Therefore, radical resection of right renal pelvis carcinoma was performed under retroperitoneal laparoscopy. Intraoperative frozen section was reported as right renal urothelial carcinoma with no metastasis in renal hilar lymph node. Postoperative histopathologic examination revealed non-invasive papillary urothelial carcinoma, low grade of renal pelvis.

我们报道了一名31岁的男性患者，患有非侵入性乳头状尿路上皮癌，低级的肾盂伪装为黄皮肉芽肿性肾盂肾炎。患者的唯一症状是下背部疼痛。最初的肾脏增强型计算机断层扫描，磁共振成像和对比增强型超声检查显示，右肾有良性病变，这种炎性病变可能是黄肿性肉芽肿性肾盂肾炎。进行了一次经皮肾活检，并且组织病理学检查显示为黄皮肉芽肿性肾盂肾炎。最初，我们将其诊断为黄皮肉瘤性肾盂肾炎，并用抗生素治疗。一年半后，患者再次遭受背部疼痛。在计算机断层扫描上，病变明显增加，右肾盂病变伴腹膜后淋巴结肿大被认为是恶性病变。因此，在腹膜后腹腔镜下进行右肾盂骨癌的根治性切除。术中冰冻切片报道为右肾尿路上皮癌，肾门淋巴结无转移。术后组织病理学检查显示无创性乳头尿路上皮癌，肾盂等级低。