Wilms tumor | Anatomy2Medicine
wilms-tumor

Wilms tumor

    • Wilms Tumor (Nephroblastoma)
      • Wilms tumor is the most common primary renal tumor in children (MCQ)

 

  • most cases are diagnosed after the first year of life. (MCQ)

 

      • arises from nephrogenic blastemal cells(MCQ)
      • malignant cells are primitive small round blue cells

 

  • they may differentiate into a variety of distinct cell types.

 

      • Classically, Wilms tumor is triphasic, with blastemal, stromal, and epithelial elements (MCQ)
        • Blastemal cells are primitive cells with high nuclear:cytoplasmic (N:C) ratios.
        • Stromal cells form fibromyxoid areas.

 

  • The epithelial component often shows some basic recapitulation of renal tubular elements.

 

      • Anaplasia is associated with an unfavorable outcome.

 

  • Mutations may be found in the WT-1 gene (MCQ)

 

        • zinc-finger transcription factor involved in renal and gonadal development(MCQ)
      • Aberrations of WT-2 are seen in Beckwith-Wiedemann syndrome.
      • Sporadic nephroblastomas often fail to reveal mutations.
      • Treatment is surgery and adjuvant chemotherapy.
      • Prognosis is generally good (> 90% long-term survival). (MCQ)

 

  • Beckwith-Wiedemann syndrome  is characterized by(MCQ)
  • macroglossia, hypoglycemia
  • organomegaly, renal cysts
  • Wilms tumor

 

      • WAGR syndrome is characterized by (MCQ)

 

  • Wilms tumor, aniridia
  • genital abnormalities
  • mental retardation.

 

      • Denys-Drash syndrome is characterized by (MCQ)

 

  • gonadal dysgenesis
  • renal failure
  • Wilms tumor

 

Topic – Neuroblastoma

Neuroblastoma

    • most common malignant neoplasm affecting infants less than 1 year of age
    • arises from the neural crest (MCQ)
    • most commonly found in the adrenal medulla (MCQ)
    • it may arise anywhere along the sympathetic chain, including the neck.
    • Abdominal mass and fever are presenting signs.
    • Some are incidentally found by prenatal ultrasound.
    • Diffusely metastatic tumors to liver, bone marrow, and skin produce the
    • so-called ‘blueberry muffin’ clinical appearance. (MCQ)
    • Neuroblastomas secrete catecholamines
      • vanillylmandelic acid [VMA]
      • homovanillic acid [HVA])

 

  • urine testing for these compounds can confirm the diagnosis and monitor for recurrence.
  • Microscopically, these tumors are arranged in sheets and pseudorosettes of
  • small round blue cells. (MCQ)
  • Tumor cells immunostain for neuroendocrine markers, such as chromo-
  • granin. (MCQ)
  • In time, or after treatment, these tumors may mature revealing ganglion cells and mature neural tissue.

 

    • Genetic aberrations include

 

  • deletion of 1p(MCQ)
  • N-myc gene amplification
  • hyperdiploidy.

 

  • N-myc amplification is associated with aggressive behavior(MCQ)
  • Hyperdiploidy is associated with a better prognosis. (MCQ)