A case of an inflammatory myofibroblastic tumor of the bladder in a young woman

We herein report a relatively rare case of an inflammatory myofibroblastic tumor (IMT) of the bladder in a young woman. In contrast to IMTs of other organs, IMTs of the lower urinary tract involve the mixture of a non-neoplastic lesion with a neoplastic lesion; therefore, the determination of whether other neoplastic lesions are present is important. In this case, magnetic resonance imaging confirmed a pedunculated lobulated tumor that protruded from the posterior left bladder wall into the lumen. The lobulated area exhibited a low-intensity signal on T1-weighted imaging (T1WI) and a high-intensity signal similar to that of urine on T2-weighted imaging (T2WI). Morphologically, the peduncle resembled a submucosal mass with faint low-intensity signaling on T1WI and faint high-intensity signaling on T2WI. These findings differ from those of a neoplastic lesion of the bladder mucous membrane. The presence of lesions from the muscularis propria to the submucosa and in areas with markedly high-intensity signals exhibiting a nodular fasciitis pattern on T2WI is considered useful for the differential diagnosis of IMT on imaging examination.