DCE-MRI using pelvic phased-array coils and simple visual diagnostic criteria is more sensitive for tumor localization than T2-weighted imaging.

A 67-year-old man with a history of melanoma, treated surgically 7 years before, was referred for vomiting and right flank pain after three intravesical instillations of bacillus Calmette-Guérin (BCG) for superficial bladder cancer. A CT scan showed a mass on the right kidney, with a normal calyx in its centre. Percutaneous biopsy, obtained because of melanoma history, showed granulomatous reaction caused by BCG infection. The renal mass disappeared after 9 months of anti-tuberculous treatment. The presence of an unaffected calyx in the centre of the renal mass is an interesting finding for both teaching purposes--it clearly illustrates the pathogeny of the disease, with the bacillus invading the renal parenchyma through the papilla--and diagnostic purposes--a malignant tumour is likely to displace or destroy neighbouring calyces rather than leaving them unaffected. However, the diagnostic value of this sign remains to be determined by further research.

No abstract