This review aims to define the 4 types of the metaverse and to explain the potential and limitations of its educational applications. The metaverse roadmap categorizes the metaverse into 4 types: augmented reality, lifelogging, mirror world, and virtual reality. An example of the application of augmented reality in medical education would be an augmented reality T-shirt that allows students to examine the inside of the human body as an anatomy lab. Furthermore, a research team in a hospital in Seoul developed a spinal surgery platform that applied augmented reality technology. The potential of the metaverse as a new educational environment is suggested to be as follows: a space for new social communication; a higher degree of freedom to create and share; and the provision of new experiences and high immersion through virtualization. Some of its limitations may be weaker social connections and the possibility of privacy impingement; the commission of various crimes due to the virtual space and anonymity of the metaverse; and maladaptation to the real world for students whose identity has not been established. The metaverse is predicted to change our daily life and economy beyond the realm of games and entertainment. The metaverse has infinite potential as a new social communication space. The following future tasks are suggested for the educational use of the metaverse: first, teachers should carefully analyze how students understand the metaverse; second, teachers should design classes for students to solve problems or perform projects cooperatively and creatively; third, educational metaverse platforms should be developed that prevent misuse of student data.

Purpose: In this study, we aimed to determine the clinicopathologic, radiologic, and molecular significance of the tumor invasiveness to further stratify the patients with high-grade (HG) upper tract urothelial carcinoma (UTUC) who can be treated less aggressively. Materials and Methods: Clinicopathologic and radiologic characteristics of 166 surgically resected HG UTUC (48 noninvasive, and 118 invasive) cases were evaluated. Six noninvasive UTUC cases with intratumoral tumor grade heterogeneity were selected for whole-exome sequencing (WES) to understand the underlying molecular pathophysiology. Barcode-tagging sequencing was done for validation of the target genes from WES data. Results: Patients with noninvasive UTUC showed no cancer-specific death with better cancer-specific survival (p < 0.001) and recurrence-free survival (p < 0.001) compared to the patients with invasive UTUC. Compared to the invasive UTUC, noninvasive UTUC was correlated to a low grade (LG) on the preoperative abdominal computed tomography (CT) grading system (p < 0.001), histologic intratumoral tumor grade heterogeneity (p=0.018), discrepancy in preoperative urine cytology diagnosis (p=0.018), and absence of urothelial carcinoma in situ (p < 0.001). WES of the heterogeneous components showed mutually shared HRAS and FGFR3 mutations shared between the HG and LG components. HRAS mutation was associated with the lower grade on preoperative abdominal CT and intratumoral tumor grade heterogeneity (p=0.045 and p < 0.001, respectively), whereas FGFR3 mutation was correlated to the absence of carcinoma in situ (p < 0.001). Conclusion According to our comprehensive analysis, HG noninvasive UTUC can be preoperatively suspected based on distinct preoperative radiologic, cytologic, histologic, and molecular features. Noninvasive HG UTUC shows excellent prognosis and thus should be treated less aggressively.