EDITORIAL COMMENT We should accept that there are attempts in all over the world to do much  less invasive treatments especially in surgical procedures. Nowadays, one of the interest areas of urologists is conservative management of upper urinary tract urothelial cancers (UUTCs). Is nephroureterectomy an overtreatment for all cases or which cases are eligible for minimally invasive therapy in UUTC. Recently, the European Association of Urology guidelines accepted conservative endoscopic treatment using ureterenoscopy for a selected group of UUTC patients with low-volume, low-grade, and low-stage disease. This study tried to explain a new technique, confocal laser endomicroscopy (CLE), for increasing accuracy of sampling in UUTC and improving the conservative management. CLE is an ultra-high-resolution microscopy technique that allows imaging of tissue at a depth of 400 µm. A negative point for CLE is the sensitivity to tissue movement leading to motion artifacts that could result in blurred images. In other studies, the benefit of CLE was shown in colon, gastric and bronchial pathologies which are luminal organs like urinary tract. Eleven patients were enrolled in this study. Four patients were previously treated endoscopically and one patient had positive cytology with no evidence of a disease in the bladder. A digital ureteroscope Flex-XC was used in all cases. After fluorescein injection, real time video sequences were acquired. Biopsies were obtained from the suspicious lesions. According to CLE findings, there were three high-grade, seven low-grade tumors and one negative tumor. Biopsy findings revealed with four not reliable, one inflammation (negative one in CLE), one dysplasia, four low-grade tumors and one high-grade tumor. It is very hard to comment on a new technique with a small amount of patients. May be it is better to say the cliché words: This study should be confirmed or validated by wide variety of studies. In addition,  although this study showed promises in the diagnosis and follow-up of UUTC with the support of studies on bladder cancer with CLE; 36% of all patients (four from all) had insufficient biopsy specimens. This means that new techniques and equipment should be developed to obtain reliable specimen by flexible endoscopes. It is probable that this evaluation will cause an increase in the applicability of this kind of techniques.