Rationale: Renal-occupying lesions positive for urine fluorescence in situ hybridization (FISH) are usually considered urothelial carcinomas. Here, we describe 2 cases of renal metastases with chromosome duplications in urine exfoliated cells. Patient symptoms: Patient 1, a 56-year-old male with a history of esophageal cancer, was admitted to our hospital on May 2017 after presenting with right back pain with microscopic hematuria for 1 month. Magnetic resonance imaging (MRI) showed right renal space-occupying lesions (5.4 cm x 4.6 cm) and multiple enlarged lymph nodes in the right renal hilum and retroperitoneum. The cystoscopy results were negative, and FISH analysis of urine exfoliated cells was positive, indicative of chromosome 3, 7, and 17 amplifications. Patient 2 was a 50-year-old male who was admitted to our hospital on May 2019 with no obvious cause of abdominal pain and abdominal distension (lasting for 7 days), with a serum creatinine level of 844 mu mol/L. Patient 2 had no hematuria or fever, and MRI showed left renal inferior and medial space-occupying lesions, and multiple mesenteric nodules at the junction of the left adrenal gland, retroperitoneum, abdomen, and pelvis, which were partially fused. The tumor lesions were approximately 3.1 cm x 2.3 cm in size. The urine FISH results were positive, indicating chromosome 3, 7, and 17 amplifications. Diagnoses: Both patients were diagnosed with renal tumors with unknown pathology. Interventions: Patient 1 underwent laparoscopic resection of the kidney and ureter, and sleeve cystectomy. The postoperative pathological diagnosis was metastatic keratinized squamous cell carcinoma, with squamous cell carcinoma in the right hilar lymph node. Histological FISH of the primary esophageal cancer and renal metastases were consistent with the urine FISH test results. Patient 2 underwent a biopsy of the left renal inferior and retroperitoneal areas, and was diagnosed with diffuse large B-cell lymphoma. Outcomes: Patient 1 survived 6 months after urological surgery. After treating patient 2 with the R-CHOP regimen and kinase inhibitors, his renal function recovered significantly and the mass become undetectable. Lessons: Our results imply that FISH-positive renal occupying lesions should be considered as potential renal metastases with chromosome aberrations when making a differential diagnosis.