Retrocaval ureter (RCU) is a rare congenital abnormality caused by impaired development of the inferior vena cava (IVC). The incidence of RCU has been estimated at around 0.1%. 1 Furthermore, RCU with a urothelial malignancy is very rare, with only 20 cases described in the literature. 2 Noda et al. reported carcinoma in situ (CIS) originating in the right RCU that was successfully managed with a laparoscopic procedure. 3
In this case report, ureteroscopy was performed because urine cytology was suspiciously positive for urothelial carcinoma. Pathological findings showed CIS in the ureter. Therefore, the authors performed right laparoscopic radical nephroureterectomy (LRNU). As the authors mentioned, this finding indicates that clinicians should consider the possibility of urothelial malignancy when examining patients with RCU. The risk factors relating to urothelial carcinoma in RCU need to be elucidated.
Few studies have reported on the treatment of RCU with a urothelial malignancy. It is highly controversial whether to resect or preserve the retrocaval segment of the ureter. In this case, the ureter was clipped by clips and cut with a sealing device to prevent dissemination of cancer cells. Recently, robotic‐assisted LRNU has been installed in many centers. 4 As Noda et al. noted, robotic assistance would allow the performance of LRNU in RCU patients without cutting the ureter. 3
In this case report, a strong adhesion was found between the ureter and IVC. The authors analyzed the mechanism of this adhesion using special stains. Of note, this staining revealed that chronic inflammation may occur in the area of adhesion and cause a wide range of fibrosis and vascular proliferation. The interesting point of this study is that CIS was found in the area of the adhesion. Although the cause and relationship between CIS and the adhesion in this case are not clear, chronic inflammation may have affected the development of CIS in this patient.
Conflict of interest
The authors declare no conflict of interest.
References
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