Inflammatory myofibroblastic tumor of the kidney misdiagnosed as renal cell carcinoma.

The inflammatory myofibroblastic tumor (IMT), also knowns as inflammatory pseuduotumor, is a soft tissue lesion of unknown etiology. In the urogenital tract, IMT mainly affects the urinary bladder or prostate, but rarely the kidney. It has been considered as a nonneoplastic reactive inflammatory lesion, but nowadays, it is regarded as a neoplasm due to its high recurrence rate and metastasis. We describe a case of a 61-yr-old woman that had originally been misdiagnosed as renal cell carcinoma, which was pathologically revealed to be an IMT.