[Can MRI be used to distinguish between superficial and invasive transitional cell bladder cancer?]

To determine the sensitivity and specificity of MRI to distinguish between superficial and invasive transitional cell bladder cancer.

Sixty patients (52 men and eight women) with a mean age of 66.8 years were assessed by bladder MRI between May 2002 and November 2005 for a primary bladder cancer diagnosed by endoscopy, followed by transurethral resection and histological examination of the bladder cancer. Patients presenting a discordance between MRI findings and histological examination were analysed.

Imaging and pathology staging was concordant for 49 bladder cancers (40 superficial and nine invasive). Ten tumours considered to be invasive on MRI were superficial on histological examination and six of them relapsed at the resection scar at one or three months. The sensitivity of MRI was 80% for a specificity of 90% and a positive predictive value of 97.5%.

MRI is a reliable examination to confirm the superficial nature of bladder cancer. When MRI and histological examination of a bladder cancer resection specimen are discordant, second look surgery is recommended to treat residual disease, which was present in 60% of cases in the present series.