Mieke Bus

4 61 Case 3 – The patient was referred with new-onset hydronephrosis of the right kidney and sus- picion of a renal pelvic tumor. Diagnostic URS combined with OCT measurements showed a mass at the ureteropelvic junction (UPJ). The basement membrane was not detectable below the tumor growth, suggesting an invasive tumor (Figure 6A-B). Average µ oct in the lesion was 3.8 ± 0.8 mm -1 . As biopsies showed high-grade urothelial carcinoma, right- sided nephroureterectomy was performed. Pathology showed a T3G3 urothelial carcinoma Figure 6: A & B) Cross-sectional OCT images (left) of the proximal ureter showing an interruption (*) of the thin dark line (#) suggesting an invasive tumor (left). Distinction between the anatomical layers is not possible. Corresponding histology (right) showed a T3G3 urothelial carcinoma (* & #). C) 3D pullback of the OCT, built from 520 individual cross-sectional images over a length of 5.2 cm.