Difference between revisions of "Pediatric kidney tumours"

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This article cover '''pediatric kidney tumours'''.  Adult kidney tumour are covered in ''[[kidney tumours]]'' article.
This article cover '''pediatric kidney tumours'''.  Adult kidney tumour are covered in ''[[kidney tumours]]'' article.


=Overview=
These are diagnoses pediatric pathologists make.
The most common ones are:
#[[Wilms tumour]].
#[[Clear cell sarcoma of the kidney]].
Other renal tumours (not covered in this article):
*Postneuroblastoma RCC.
*Neuroblastoma.
*[[PNET]].
*[[Synovial sarcoma]].
*[[Lymphoma]].
=Specific tumours=
==Wilms tumour==
==Wilms tumour==
*[[AKA]] nephroblastoma, AKA Wilms' tumour.
*[[AKA]] nephroblastoma, AKA Wilms' tumour.
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:See: ''[[Renal_cell_carcinoma|(adult) renal cell carcinoma]]''.
:See: ''[[Renal_cell_carcinoma|(adult) renal cell carcinoma]]''.


==See also==
=See also=
*[[Genitourinary pathology]]
*[[Genitourinary pathology]]
*[[Kidney tumours]].
*[[Kidney tumours]].
*[[Pediatric pathology]].
*[[Pediatric pathology]].


==References==
=References=
{{Reflist|2}}
{{Reflist|2}}


[[Category:Genitourinary pathology]]
[[Category:Genitourinary pathology]]

Revision as of 22:13, 1 October 2011

This article cover pediatric kidney tumours. Adult kidney tumour are covered in kidney tumours article.

Overview

These are diagnoses pediatric pathologists make.

The most common ones are:

  1. Wilms tumour.
  2. Clear cell sarcoma of the kidney.

Other renal tumours (not covered in this article):

Specific tumours

Wilms tumour

  • AKA nephroblastoma, AKA Wilms' tumour.

General

Gross

  • Lobulated tan mass.

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

Microscopic

Features - classically three components (blastema, immature stroma, tubules):[5]

  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.[6]
  • +/-Heterologous elements (skeletal muscle, smooth muscle adipose tissue, cartilage).[7]
    • Heterologous = doesn't normally belong there.[8]

DDx:

  • Metanephric adenoma.
  • Nephrogenic nests.
  • Other small round cell tumours.
  • Synovial sarcoma - esp. in adults.

Notes:

  • Palisade = fence made of stakes driven into the ground.[9]
  • Approximately 30-40% Wilms tumour cases have nephrogenic rests.[10]
  • The three phases are also called blastemal, epithelial and stromal.[7]

Images:

Anaplasia

Subclassified as:[7]

  1. Focal anaplasia.
  2. Diffuse anaplasia.

Criteria (all of the following):[7]

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

IHC

  • WT-1 +ve.

Metanephric stromal tumour

  • Abbreviated MST.

General

Gross

Features:[11]

  • Usu. renal medulla.
  • Solid or cystic.

Microscopic

Features:[11]

  • "Collarettes" - tumour cells surround blood vessels or renal tubules.
  • Spindle cells/stellate cells.
  • Variable cellular density - imparts a nodular appearance at low power.
  • Indistinct cell borders/cytoplasm.
  • Induces epithelioid morphology in smooth muscle cells.

Notes:

  • +/-Heterologous elements.

DDx:

Images:

Metanephric adenofibroma

General

  • Adults and children.

Microsopic

Features:[11]

Mesoblastic nephroma

General

  • Almost exclusively in infants.

Subclassified:

  1. Classic.
  2. Cellular.
  3. Mixed.

Gross

  • Renal sinus infiltration - common.

Microscopic

Classic

Features:[13]

  • Spindle cells in fascicles.
  • Infiltrative border.

Cellular

Features:[13]

  • Plump cells with vesicular nuclei.
  • Well-defined border.
  • Mitotically active.

Mixed

  • Like the name implies - both classic pattern and cellular pattern areas are present.[13]

Molecular

Cellular mesoblastic nephroma:

Clear cell sarcoma of the kidney

General

  • Common pediatric renal tumour - second only to Wilms tumour.
  • Aggressive.

Gross

  • Renal medulla.
  • +/-Cystic.

Microscopic

Features:[13]

  • Polygonal cells/Stellate cells.
  • Indistinct cell borders/cytoplasm; clear background.
  • No nucleoli.

Renal rhabdoid tumour

  • AKA rhabdoid tumour of the kidney, abbreviated RTK.

General

Microscopic

Features:[14][13]

  • Variable architecture.
  • Round cells.
  • Abundant cytoplasm with eosinophilic inclusions.
  • Eccentric vesicular nucleus.
  • Prominent nucleolus -- key feature.

IHC

  • INI1 -ve.

Renal cell carcinoma

General

  • Similar to in adults.
  • Clear cell RCC not common - a tumour with the clear cell histomorphology is more often a renal tumour with a Xp11.2 translocation.

Papillary RCC

See: (adult) renal cell carcinoma.
  • Most common form of RCC in children.

Clear cell RCC

See: (adult) renal cell carcinoma.

See also

References

  1. ↑ URL: http://emedicine.medscape.com/article/989398-overview. Accessed on: 9 March 2011.
  2. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 194072
  3. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 130650
  4. ↑ Online 'Mendelian Inheritance in Man' (OMIM) 194080
  5. ↑ 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.
  6. ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970416-8. Accessed on: 28 March 2011.
  7. ↑ 7.0 7.1 7.2 7.3 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.
  8. ↑ URL: http://www.biology-online.org/dictionary/Heterologous. Accessed on: 1 October 2011.
  9. ↑ URL: http://www.thefreedictionary.com/palisaded. Accessed on: 2 February 2011.
  10. ↑ 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.
  11. ↑ 11.0 11.1 11.2 11.3 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 283. ISBN 978-0781765275.
  12. ↑ 12.0 12.1 Palese, MA.; Ferrer, F.; Perlman, E.; Gearhart, JP. (Sep 2001). "Metanephric stromal tumor: a rare benign pediatric renal mass.". Urology 58 (3): 462. PMID 11549506.
  13. ↑ 13.0 13.1 13.2 13.3 13.4 13.5 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 284. ISBN 978-0781765275.
  14. ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 627. ISBN 978-0781765275.
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