Wilms tumour

From Libre Pathology
Revision as of 01:45, 6 May 2014 by Michael (talk | contribs)
Jump to navigation Jump to search

Wilms tumour, also nephroblastoma and Wilms' tumour, is the most common pediatric kidney tumour.[1][2]

Wilms tumour
Diagnosis in short

Wilms tumour. H&E stain.
Synonyms nephroblastoma
LM DDx small round cell tumours
IHC WT-1 +ve
Site kidney - see pediatric kidney tumours
Syndromes WAGR syndrome, Beckwith-Wiedemann syndrome, Denys-Drash syndrome
Signs abdominal mass
Prevalence most common pediatric kidney tumour

General

Gross

  • Lobulated tan mass.

Image: Wilms tumour (med.utah.edu).

Microscopic

Features - classically three components (blastema, immature stroma, tubules):[7]

  1. Malignant small round blue cells ("blastema"):
    • Size = ~ 2x RBC diameter.
    • Nuclear pleomorphism (variation of size, shape and staining).
      • Irregular nuclear membrane - important.
    • Scant/difficult to discern cytoplasm - basophilic (light blue).
    • Mitoses - common.
  2. Stroma ("immature stroma"):
    • Spindle cells:
      • Elliptical nuclear membrane.
      • Abundant loose cytoplasm.
  3. Tubular structures ("tubules"):
    • Usually clustered.
    • Vaguely resemble a glomerulus.
    • Usu. have a central (clear/white) space surrounded by a rim of intensely eosinophilic cytoplasm.
    • Nuclei of tubular structures often elongated and palisaded.

Other findings:

  • Commonly seen in association with nephrogenic rests.
    • Cluster of cells small (blue) cells; lack nuclear atypia seen in Wilms tumour.[8]
  • +/-Heterologous elements (skeletal muscle, smooth muscle adipose tissue, cartilage).[9]
    • Heterologous = doesn't normally belong there.[10]

DDx:

Notes:

  • Palisade = fence made of stakes driven into the ground.[11]
  • Approximately 30-40% Wilms tumour cases have nephrogenic rests.[12]
  • The three phases are also called blastemal, epithelial and stromal.[9]

Images

  • Wilms tumour - low mag. (WC/Nephron)

  • Wilms tumour - intermed. mag. (WC/Nephron)

  • Wilms tumour - high mag. (WC/Nephron)

  • Wilms tumour - very high mag. (WC/Nephron)

www:

Anaplasia

Subclassified as:[9]

  1. Focal anaplasia.
  2. Diffuse anaplasia.

Criteria (all of the following):[9]

  1. Atypical mitoses.
  2. Nuclear hyperchromasia.
  3. Nuclear size variation (of the tumour cells) > 3x.

IHC

  • WT-1 +ve.

See also

References

  1. ↑ Coppes MJ, Wolff JE, Ritchey ML (1999). "Wilms tumour: diagnosis and treatment". Paediatr Drugs 1 (4): 251–62. PMID 10935424.
  2. ↑ Stefanowicz J, Sierota D, Balcerska A, Stoba C (2004). "[Wilms' tumour of unfavorable histology--results of treatment with the SIOP 93-01 protocol at the Gdańsk centre. Preliminary report]" (in Polish). Med Wieku Rozwoj 8 (2 Pt 1): 197–200. PMID 15738594.
  3. ↑ URL: http://emedicine.medscape.com/article/989398-overview. Accessed on: 9 March 2011.
  4. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 194072
  5. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 130650
  6. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 194080
  7. ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 254-5. ISBN 978-1416054542.
  8. ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970416-8. Accessed on: 28 March 2011.
  9. ↑ 9.0 9.1 9.2 9.3 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 282. ISBN 978-0781765275.
  10. ↑ URL: http://www.biology-online.org/dictionary/Heterologous. Accessed on: 1 October 2011.
  11. ↑ URL: http://www.thefreedictionary.com/palisaded. Accessed on: 2 February 2011.
  12. ↑ Coppes MJ, Haber DA, Grundy PE (September 1994). "Genetic events in the development of Wilms' tumor". N. Engl. J. Med. 331 (9): 586–90. doi:10.1056/NEJM199409013310906. PMID 8047084.
Retrieved from "https://librepathology.org/w/index.php?title=Wilms_tumour&oldid=31324"