Renal Cell Carcinoma

Overview
  • Renal Cell Carcinomas (RCCs) are a morphologically diverse set of neoplasms arising from the tubular epithelial cell. Because they are derived from the tubular epithelial cell, most RCCs are located in the renal cortex.
Common Subtypes
  • Clear Cell Carcinoma
    • Incidence: Account for about 80% of total RCCs. Most cases are sporadic but can be familialy inherited as part of von Hippel-Lindau Disease (VHL).
    • Pathogenesis: Genetic lesions in the VHL tumor Suppressor gene are present in nearly all cases (familial or sporadic)
    • Morphology: Are composed of polygonal cells with a clear or granular cytoplasm (hence the name) and are usually well-differentiated although significant atypia may be present
  • Papillary Renal Cell Carcinomas
    • Incidence: Account for about 15% of total RCCs. The most common subtype in those with acquired cystic disease
    • Morphology: Neoplastic cells grow in a papillary architecture (hence the name)
Location and Spread
  • RCCs can occur any where in the renal parenchyma although the poles are preferred. As RCCS enlarge they can grow into the renal pelvis, renal calyces, and even into the ureter. Surprisingly, RCCs can also grow into the renal vein and extend as a solid tube into the inferior vena cava and even into the right heart.
Clinical Consequences
  • The classic triad of RCC is a that of hematuria, abdominal pain, and palpable mass of the abdomen or flank. RCCs are malignant and tend to metastasize before any symptomology arises. Prognosis worsens with increasing size, invasion, and metastasic spread of the tumor. Additionally, RCCs can elaborate hormones resulting in a paraneoplastic syndrome. Polycythemia may occur as a result of erythropoietin production. hypercalcemia can occur as a result of PTH-like peptide production.
Incidence
  • RCC typically manifests in the elderly and is the most common renal tumor. Several risk factors appear to increase incidence of the disease.
  • Smoking: Likely the most important risk factor
  • Dialysis: Dialysis that results in acquired cystic disease increases risk of the papillary subtype of RCC
  • Von Hippel-Lindau Disease: VHL increases the risk of clear cell subtype as those with the condition inherit defective copies of the VHL gene