Difference between revisions of "Desmoid-type fibromatosis"

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==Molecular==
==Molecular==
*Sporadic desmoids (~85%)
*Sporadic desmoids (~85%).
**point mutations in the CTNNB1 gene which encodes β-catenin
**Point mutations in the CTNNB1 gene which encodes β-catenin.
**constitutively active β-catenin
**Constitutively active β-catenin.
*Syndromic desmoids (~5%)
*Syndromic desmoids (~5%):
**loss of function mutation in APC
**Loss of function mutation in [[APC]].
**loss of breakdown of β-catenin
**Loss of breakdown of β-catenin.
**constitutively active β-catenin
**Constitutively active β-catenin.


==Sign out==
==Sign out==

Revision as of 06:47, 3 October 2014

Desmoid-type fibromatosis
Diagnosis in short

Desmoid-type fibromatosis. H&E stain.

LM "sweeping fascicles"/bundles, spindle cells with small slender nuclei, solid dark eosinophilic cytoplasm, +/-mitoses, long thin-walled vessels - parallel to one another
LM DDx hypertrophic scar, gastrointestinal stromal tumour, retroperitoneal fibrosis, other fibromatoses, nodular fasciitis, schwannoma
IHC beta-catenin +ve (nuclear), SMA +ve/-ve, CD117 -ve
Molecular sporadic point mutations in the CTNNB1 gene which encodes β-catenin
Site soft tissue

Syndromes familial adenomatous polyposis - esp. Gardner syndrome

Prevalence uncommon
Prognosis benign but locally aggressive
Clin. DDx trauma/hematoma

Desmoid-type fibromatosis is a benign soft tissue lesion in the fibroblastic/myofibroblastic group of tumours.

It is also known as desmoid tumour and desmoid fibromatosis.

General

Gross

Features:[2]

  • Location:
    • Abdominal wall, proximal extremities - classic for adolescents and women.
    • Head and neck - classic for children.
  • Circumscribed mass.
  • May be quite large (>10 cm).

Microscopic

Features:[2][3]

  • "Sweeping fascicles"/bundles.
  • Spindle cells with:
    • Small slender nuclei.
    • Solid dark eosinophilic cytoplasm.
  • +/-Mitoses - may be abundant.
  • Long thin-walled vessels - parallel to one another - important feature.

DDx:

Images

www:

IHC

Features:[2]

  • Beta-catenin +ve (nuclear[4]) - important.
    • 100% sensitive... may not be completely specific (?).[8]
    • Staining may be difficult to interpret as the nucleus may be small, the cytoplasm scant and the precipitate grainy and vague. Ensure that the staining seen is nuclear (or nuclear and cytoplasmic). Cytoplasmic staining alone can occur and is not a true positive.
  • SMA +ve ~50% of lesions.

Others:

  • CD117 -ve.
  • DOG1 -ve.
  • CD34 -ve.

Molecular

  • Sporadic desmoids (~85%).
    • Point mutations in the CTNNB1 gene which encodes β-catenin.
    • Constitutively active β-catenin.
  • Syndromic desmoids (~5%):
    • Loss of function mutation in APC.
    • Loss of breakdown of β-catenin.
    • Constitutively active β-catenin.

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LESION, ABDOMINAL WALL, BIOPSY:
- DESMOID-TYPE FIBROMATOSIS.

COMMENT:
The tumour stains strongly with beta-catenin and weakly with SMA. It is negative for CD117.

See also

References

  1. URL: http://www.dtrf.org/dtrf_aboutdesmoids.htm. Accessed on: 15 April 2011.
  2. 2.0 2.1 2.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 609. ISBN 978-0781765275.
  3. URL: http://www.surgicalpathologyatlas.com/glfusion/mediagallery/media.php?f=0&sort=0&s=20090717111548196. Accessed on: 4 October 2011.
  4. 4.0 4.1 4.2 Huss, S.; Nehles, J.; Binot, E.; Wardelmann, E.; Mittler, J.; Kleine, MA.; Künstlinger, H.; Hartmann, W. et al. (Jan 2013). "β-catenin (CTNNB1) mutations and clinicopathological features of mesenteric desmoid-type fibromatosis.". Histopathology 62 (2): 294-304. doi:10.1111/j.1365-2559.2012.04355.x. PMID 23020601.
  5. Thalheimer, A.; Meyer, D.; Gattenlöhner, S.; Timmermann, W.; Thiede, A. (Jul 2004). "[Gastrointestinal stromal tumor of the abdominal wall. An unusual localization of a rare tumor].". Chirurg 75 (7): 708-12. doi:10.1007/s00104-003-0696-5. PMID 15257404.
  6. URL: http://www.cheapmedicinechest.com/abdominal-pain-and-colonic-obstruction-from-an-intra-abdominal-desmoid-tumor.html. Accessed on: 4 October 2011.
  7. Ma, JH.; Ma, ZH.; Dong, XF.; Yin, H.; Zhao, YF. (Jun 2013). "Abdominal wall desmoid tumors: A case report.". Oncol Lett 5 (6): 1976-1978. doi:10.3892/ol.2013.1297. PMID 23833679.
  8. Amary, MF.; Pauwels, P.; Meulemans, E.; Roemen, GM.; Islam, L.; Idowu, B.; Bousdras, K.; Diss, TC. et al. (Sep 2007). "Detection of beta-catenin mutations in paraffin-embedded sporadic desmoid-type fibromatosis by mutation-specific restriction enzyme digestion (MSRED): an ancillary diagnostic tool.". Am J Surg Pathol 31 (9): 1299-309. doi:10.1097/PAS.0b013e31802f581a. PMID 17721184.