4. 1. Oncocytoma (Benign Oxyphilic
Adenoma):
• Second most common benign renal tumor.
• 6th
-7th
Decades.
• Male:Female = 3-1
• Asymptomatic.
• 10% bilateral- 10% multiple.
• In less than 10% of cases, oncocytoma and
chromophobe RCC may coexist
Renal tumors
5. Pathology:
• Cortical.
• Solid mass with stellate scar in 33-54% of tumors .
• Vascular.
• Very rare calcifications.
Oncocytoma
6. A. Plain X-Ray:
• Normal.
• Soft tissue mass displacing renal shadow and
surrounding fat planes.
Oncocytoma
7. B. IVU:
• Normal.
• Soft tissue mass displacing
renal shadow and
surrounding fat planes.
Oncocytoma
8. C. US:
• Well-defined.
• Solid mass.
• Homogenous.
• Hypo- to isoechoic.
• Hyperechoic central scar.
Oncocytoma
9. D. CT:
• NECT scans, isoattenuating or
slightly hyperattenuating.
• A central hypoattenuating scar
observed in 33% of cases
Oncocytoma
10. 1. CT:
• CECT scans, nephrographic phase, the mass
appears less attenuating than the renal
parenchyma
Oncocytoma
11. E. MRI:
• T1-weighted images:
• Pre: isointense to hypointense relative to the
renal cortex.
Oncocytoma
12. E. MRI:
• T1-weighted images:
• Post: Homogeneous enhancement, with a
nonenhancing central scar.
Oncocytoma
13. E. MRI:
• T2-weighted images:
• Isointense to slightly hyperintense or
hypointense.
• Spoke-wheel hypointense pattern.
Oncocytoma
14. F. Angiography:
• Spoke-wheel arrangement of
tumoral vessels.
• Homogeneous tumoral contrast
during the capillary phase.
• Sharp demarcation from the
kidney and surrounding areas.
• Peritumoral halo (lucent-rim sign).
• The bizarre neoplastic vessels are
conspicuously absent, in contrast
to RCC.
Renal tumorsOncocytoma