Upper-tract urothelial carcinoma on CT urography

CT

First and second year — the floor first, then every step

Haematuria work-up: a filling defect, wall thickening or a mass in the pelvicalyceal system or ureter on the excretory phase — and multifocality, because urothelial cancer is a field disease.

Orient first

  • Upper-tract tumours are much rarer than bladder tumours but often multifocal and synchronous with bladder cancer.
  • On excretory images they are filling defects or strictures; on nephrographic images an infiltrating tumour preserves the reniform shape (unlike RCC, which distorts it).
  • Stones, clot and papillary necrosis are the mimics.

Acquire the study

  • CT urography: unenhanced, nephrographic (~100 s) and excretory (8–15 min) phases, or split-bolus; thin slices with coronal MIP and curved reformats of the ureters.

The manoeuvre

  • Unenhanced series: stones and clot (higher attenuation than tumour).
  • Excretory phase: every calyx, the pelvis and both ureters to the bladder — filling defects, irregularity, amputated calyx.
  • Nephrographic phase: enhancing soft tissue in the collecting system or wall thickening; measure the enhancement in HU.
  • Periureteric and renal sinus fat invasion; nodes (para-aortic, interaortocaval).
  • Bladder: a synchronous tumour.

What confirms it

  • An enhancing filling defect or wall thickening in the upper tract without a stone or clot explanation; ureteroscopy with biopsy confirms.

What licenses you to exclude it

  • Well-opacified, smooth collecting systems and ureters on the excretory phase make an upper-tract tumour very unlikely.

The classic misread

  • Reading an unopacified ureteric segment (peristalsis) as normal — add a prone or delayed image series.
  • Missing a tumour inside a hydronephrotic system that never opacifies.

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