Gadolinium Contrast in the Bladder: A Malignant Mimic

A 50-year-old female presented to hospital with diplopia and unsteady gait. The patient was identified to have a disconjugate gaze palsy involving the right medial rectus muscle. Investigation for an ischaemic event proved negative, with an unremarkable MRI of the brain. A paraneoplastic screen, including a CT of the chest, abdomen, and pelvis, was undertaken to identify an alternative cause for her symptoms.

An incidental finding of a large, enhancing bladder mass was identified on CT imaging (Figure 1 and Figure 2). The bladder mass was hyperdense arising from the anterior bladder wall and had an atypical serpiginous appearance. There was no hydroureteronephrosis. Differentials included a bladder lesion or, less likely, an organised haematoma. The patient had a significant smoking history but no prior haematuria. Urine cytology was negative, and a renal tract ultrasound failed to identify the lesion.

Flexible cystoscopy was performed, demonstrating a normal appearing bladder. Further discussion with the radiol- ogists identified that the gadolinium contrast given for her MRI scan 2 hours before the CT scan was likely layering within the bladder, masquerading as a bladder lesion.