case_images: PMC8138232_01
case_images: a-d Abdominal CT scan showing hydronephrosis (arrows) on the right (a, b, d), caused by a mass (arrows) in the middle third of the ureter (c, d).
case_images: crg-0015-0450-g01.jpg
case_images: PMC8138232_01_crg-0015-0450-g01.jpg
case_images: F1
case_images: Then, a hydronephrosis grade 2 on the right side caused by a ureteral mass of the middle third was found at CT (Fig. 1a-d).
case_images: a, b Specimen after right nephroureterectomy demonstrating a complete malignant ureteral obstruction caused by metastasis (arrow in a) as well as a second smaller metastasis to the right renal pelvis (arrow in b).
case_images: crg-0015-0450-g02.jpg
case_images: PMC8138232_01_crg-0015-0450-g02.jpg
case_images: F2
case_images: At surgery, induration of the middle third of the right ureter was found and a right nephroureterectomy was performed (Fig. 2a, b).
case_images: a-c Immunohistochemistry showing a positive CDX2 expression in the metastasis (a) (arrows) and a positive GATA3 expression only in the urothelium (b, arrows). c No signs of tumor infiltration to the outer layers of the ureter (arrows show margins of the tumor growing intramucosal) can be seen.
case_images: crg-0015-0450-g03.jpg
case_images: PMC8138232_01_crg-0015-0450-g03.jpg
case_images: F3
case_images: At immunohistochemistry, a double metastasis of the known rectal cancer both to the right ureter and to the right renal pelvis was confirmed by a positive CDX2 expression in the neoplasm, whereas a positive GATA3 expression was found only in the urothelium (Fig. 3a, b). Histology revealed only mucosal infiltration by the tumor without involvement of the periureteral tissue resulting in a tumor-free circumferential resection margin (Fig. 3c).