Ameloblastoma

From Libre Pathology
Revision as of 15:16, 23 February 2014 by Michael (talk | contribs)
Jump to navigation Jump to search

Ameloblastoma is an odontogenic cyst.

Ameloblastoma
Diagnosis in short

Ameloblastoma. H&E stain.
LM stellate reticulum (star-shaped cells), tall columnar cells that have palisaded nuclei with reverse polarization, subnuclear vacuolization, +/-giant cells, +/-subepithelial hyalinization (eosinophilic acellular amorphous material)
Subtypes solid/multicystic, unicystic
LM DDx adenomatoid odontogenic tumour, ameloblastic fibroma
Site usu. mandible - see odontogenic tumours and cysts
Prevalence uncommon
Clin. DDx keratocystic odontogenic tumour, odontogenic cysts

General

  • Osteous lesion.
  • Usually mandible.[1]
    • In a review of 3677 cases, the mandible-to-maxilla ratio was 5 to 1.[2]
  • May arise from an odontogenic cyst,[3] e.g. dentigerous cyst.[4]

Classification

Location:

  1. Intra-osseous.
    • Locally aggressive.
  2. Peripheral.
    • Benign.

Subclassification of intra-osseous type

Histology:

  1. Solid/multicystic.
    • More commonly reoccur.
  2. Unicystic.
    • Unlikely to reoccur.
    • Classically found in younger individuals.

Microscopic

Features:[5]

  • Stellate reticulum - star-shaped cells, found in a developing tooth.
  • Tall columnar cells.
    • Palisaded nuclei with reverse polarization.
      • Reverse polarization of nuclei = nuclei distant from the basement membrane/nuclei at pole opposite of basement membrane.
      • Palisaded nuclei = picket fence appearance; columnar-shaped nuclei with long axis perpendicular to the basement membrane -- key feature.
    • Subnuclear vacuolization.
  • +/-Giant cells.
  • +/-Subepithelial hyalinization (eosinophilic acellular amorphous material).
    • Seen deep to the basement membrane.
  • Variable morphology (see below - morphology).

DDx (nuclear palisading):

Images

www:

  • Ameloblastoma - low mag. (WC)

  • Ameloblastoma - intermed. mag. (WC)

  • Ameloblastoma - high mag. (WC)

  • Ameloblastoma - very high mag. (WC)

Morphology

  • Not prognostic.

Morphologic variants:

  • Follicular ameloblastoma (classic appearance).
  • Plexiform ameloblastoma (does not have prominent palisading).
  • Acanthomatous ameloblastoma.
  • Desmoplastic ameloblastoma.
  • Basaloid ameloblastoma.

See also

References

  1. ↑ URL: http://www.waent.org/archives/2010/Vol3-2/20100618-ameloblastoma/jaw-tumor.htm. Accessed on: 30 November 2011.
  2. ↑ Reichart, PA.; Philipsen, HP.; Sonner, S. (Mar 1995). "Ameloblastoma: biological profile of 3677 cases.". Eur J Cancer B Oral Oncol 31B (2): 86-99. PMID 7633291.
  3. ↑ Eversole, LR. (Nov 1999). "Malignant epithelial odontogenic tumors.". Semin Diagn Pathol 16 (4): 317-24. PMID 10587275.
  4. ↑ Moosvi, Z.; Tayaar, SA.; Kumar, GS. (Apr 2011). "Neoplastic potential of odontogenic cysts.". Contemp Clin Dent 2 (2): 106-9. doi:10.4103/0976-237X.83073. PMC 3180832. PMID 21957386. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3180832/.
  5. ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970616-7. Accessed on: March 9, 2010.
Retrieved from "https://librepathology.org/w/index.php?title=Ameloblastoma&oldid=29787"