J Korean Med Sci.  2010 Feb;25(2):330-332. 10.3346/jkms.2010.25.2.330.

Inflammatory Myofibroblastic Tumor of the Kidney Misdiagnosed as Renal Cell Carcinoma

• Ryu KH
• Im CM
• Kim MK
• Kwon D
• Park K
• Ryu SB
• Choi C

• KMID: 1779272
• DOI: http://doi.org/10.3346/jkms.2010.25.2.330

Abstract

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.

Keyword

Granuloma, Plasma Cell; Inflammation; Kidney Neoplasms

MeSH Terms

Actins/metabolism
Carcinoma, Renal Cell/diagnosis/pathology
Diagnosis, Differential
*Diagnostic Errors
Female
Granuloma, Plasma Cell/*diagnosis/pathology/surgery
Humans
Kidney Neoplasms/*diagnosis/pathology
Magnetic Resonance Imaging
Middle Aged
Tomography, X-Ray Computed
Vimentin/metabolism
Actins
Vimentin

Figure

• 

  Fig. 1 Magnetic resonance image demonstrates a 3.0×2.5 cm size solid mass with mildly enhancement on left kidney lower pole with a central necrotic portion.

• 

  Fig. 2 Left kidney coronal opening specimen shows a well-circumscribed encapsulated mass measuring 2.7×2.8 cm size, involving the lower pole. The mass revealed areas of myxoid change necrosis, and cystic change.

• 

  Fig. 3 Microscopic findings. (A) The low power appearance demonstrating a capsule of dense collagenous fibrous tissue and myxoid zone and inflammation with cellular zone consisting of spindle cells arranged in fascicles. (B) The area of myofibroblastic proliferation showing densely cellular fascicles. The tumor cells were potive for smooth muscle actin (C) and vimentin (D).

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