Renal cell carcinoma

The most common primary renal malignancy

Key imaging characteristics

• Enhances (>15 HU)
  • <10 HU = no sig.
  • 10-15 HU = equivocal, suspicious if large (>1.5 cm)
• Calcifications in a fatty mass
  • If no Ca2+ → AML

Risk factors

• Tobacco use
• Chronic dialysis (>3 years)
• Family history
• Cancer syndrome
  • VHL

Subtypes

Clear cell

• The most common subtype in general population
• Assoc. with VHL
• More aggressive than papillary
• Enhance equal to the cortex on corticomedullary phase

Papillary

• The second most common subtype
  • Likely to occurs in transplanted kidney
• Less aggressive than clear cell
• Less vascular → enhance less than cortex on corticomedullary phase
• Differential: Renal hypoT2 lesions

Medullary

• Typically younger patient
• Assoc. with sickle cell trait
• Highly aggressive → usually large and metastasized at the time of diagnosis

Chromophobe

• Assoc. with Birt Hogg Dube syndrome

Translocation

• Most common subtype in kids
• Assoc. with prior cytotoxic chemotherapy

Staging

• Limit to kidney
  • I: < 7 cm
  • II: > 7 cm
• Extended beyond renal capsule but still inside Gerota's fascia: III
  • IIIA: Invaded renal vein
  • IIIB: Invaded IVC below diaphragm
  • IIIC: Invaded IVC above diaphragm
• Beyond Gerota's fascia: IV