UNASSIGNED: Small cell neuroendocrine carcinoma (SCNEC) of the ureter is a rare tumour, accounting for less than 0.5% of all ureteral tumours. SCNEC tumours are highly aggressive and patients have a poor prognosis. Ureteral SCNEC colliding with other pathological types of tumours is extremely rare. In this paper, we present the case of a patient with ureteral small cell carcinoma colliding with squamous cell carcinoma and review the literature regarding the clinicopathological features, treatment and prognosis of thus tumour. To the best of our knowledge, this is the second identified case of ureteral SCNEC colliding with SCC.
UNASSIGNED: A 64-year-old male patient presented with a history of 1 month of gross haematuria and 3 months of left flank pain. CT urography revealed a soft tissue mass in the upper ureter, which was slightly enhanced on contrast-enhanced CT. Nephroureterectomy was performed after the patient was diagnosed with a tumour in the left ureter. Microscopy and immunohistochemical examination confirmed the mass to be a SCNEC collision with SCC. Two months after the surgery, the patient received adjuvant chemotherapy (cisplatin/etoposide). After 14 months of follow-up, no local recurrence or distant metastasis was found.
UNASSIGNED: Ureteral collision carcinoma with SCNEC predominantly occurs in Asian individuals, is difficult to diagnose preoperatively and is highly invasive. The current management of ureteral collision carcinoma is a comprehensive treatment based on surgery.

OBJECTIVE: To describe our experience in handling cases of children with fibroepithelial polyps (FEPs) of ureters. We specifically present preoperative diagnosis approaches, provide a clear definition of this entity and its outcomes following treatment.
METHODS: Clinical data of children with FEPs who were consecutively treated at Beijing Children\'s Hospital from January 2006 to May 2019 were retrospectively analyzed in this study. The clinical data reviewed included diagnostic, intraoperative, and follow-up data.
RESULTS: Of the 2653 children with surgery for hydronephrosis reviewed, 48 (1.8%) cases of FEPs of the ureters were identified, with a mean age of 109 ± 34.7 months. Among them, males accounted for 95.8%, left side for 81.3%, and proximal ureteral polyps for 97.9%. Notably, 70.8% of patients had only 1 polyp and the median size of the polyps was 2.1 ± 1.8 cm. All patients underwent ultrasound before surgery, which revealed the existence of polyps in 29 (60.4%) children. These polyps were completely resected surgically. The mean follow-up was 82 months (range of 6-153 months) and no cases of recurrences of polyps were seen after surgery during follow-up. The rate of other long-term complications was 9.3%.
CONCLUSIONS: In conclusion, FEPs are one of the important causes of hydronephrosis in children. Ultrasound is effective for preoperative diagnosis achieving higher true positive rates than other diagnostic methods. Although the recurrence rate of polyps and symptoms are low after complete resection in children, long-term follow-up is advocated to the adolescence stage to monitor the incidences of urinary tract infections, ureteropelvic junction obstruction and stone formation.