J Korean Soc Radiol.  2018 Apr;78(4):289-294. 10.3348/jksr.2018.78.4.289.

Radiologic Findings of Renal Schwannoma: A Case Report and Literature Review

• Hwang ST
• Sung DJ
• Sim KC
• Han NY
• Park BJ
• Kim MJ
• Lee JH

• KMID: 2407935
• DOI: http://doi.org/10.3348/jksr.2018.78.4.289

Abstract

Schwannoma is a benign nerve sheath tumor that involves Schwann cells mostly found in the head, neck, posterior mediastinum and extremities. Schwannoma develops rarely in the retroperitoneum; thus, renal schwannoma is extremely uncommon. Differentiation of renal schwannoma from renal cell carcinoma is difficult with radiologic analysis. A few cases of these tumors have been reported in literature, and little has been described regarding imaging appearances. In this study, we present a rare case of a renal schwannoma, resembling renal cell carcinoma, with radiological correlations.

MeSH Terms

Carcinoma, Renal Cell
Extremities
Head
Kidney
Mediastinum
Neck
Nerve Sheath Neoplasms
Neurilemmoma*
Schwann Cells

Figure

• 

  Fig. 1 Renal schwannoma in a 66-year-old man. A. Axial, coronal and sagittal contrast-enhanced computed tomography images reveal heterogeneously enhanced mass with cystic portions (white arrows) measuring approximately 11.2 cm in diameter in the upper pole of the right kidney. Renal vessels are deviated due to mass effect of the large mass (arrowheads). The heterogeneously enhanced mass in the liver is pathologically proven to be hepatocellular carcinoma (black arrow). B. Axial T2-weighted turbo spin-echo and axial T1-weighted turbo spin-echo magnetic resonance images revealing a well-circumscribed, large mass with heterogeneously T2 hypersignal intensity and heterogeneously T1 hyposignal intensity. Cystic portions (arrows) are shown in the mass on T2WI. Multifocal hypersignal intensities (arrowheads) in the mass on T1WI suggest hemorrhagic portions. Axial contrast-enhanced T1-weighted magnetic resonance imaging reveals inhomogeneous tumoral enhancement on portal phase. DWI (b-value = 800 s/mm2) reveals hypersignal intensity in solid portion of the mass. The mass demonstrates low ADC value. ADC = apparent diffusion coefficient, DWI = diffusion weighted imaging, T1WI = T1-weighted image, T2WI = T2-weighted image C. Gross specimen reveals an multilobulated mass, measuring 12.2 × 9.0 cm. On section, the cut surface reveals a yellowish to tan inhomogeneous appearance with cystic degeneration. D. Histologic specimen reveals the section from the renal mass is mostly composed of spindle cells (hematoxylin and eosin stain, × 200). Tumor cells reveal diffuse positivity to S-100 immunostain (× 40).

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