A 78 year old woman has recent history of urothelial cancer of the renal pelvis status post right nephrectomy. She undergoes an FDG PET/CT for an indeterminate liver lesion.
The liver lesion was not suspicious. PET/CT images of the pelvis are below. Do you see any abnormality?
There is an FDG-avid soft tissue nodule at the anterior aspect of the bladder.
The patient also had a multiphase CT, which demonstrated an arterially-enhancing nodule in this location within the bladder (which is less distended on these images).
This patient was proven to have urothelial carcinoma of the bladder.
Although FDG PET is notoriously insensitive for tumors of the urinary tract (due to urinary excretion of FDG), malignant lesions may still be identified in selected cases by careful adjustment of window settings.
Given her history, this patient is at high risk of having a new site of urothelial cancer (metachronous lesion). In one classic study of this disease, metachronous urothelial cancer was found in 3.9% of patients with bladder cancer, 11% of patients with renal cancer, and 13% of patients with ureteral cancer. Synchronous sites of malignancy were found in 2.3%, 24%, and 39% respectively. Yousem DM, et al. Radiology 1988;167:613-618.
