Difference between revisions of "Ameloblastoma"

From Libre Pathology
Jump to navigation Jump to search
(split out)
(+infobox)
Line 1: Line 1:
{{ Infobox diagnosis
| Name      = {{PAGENAME}}
| Image      = Ameloblastoma - high mag.jpg
| Width      =
| Caption    = Ameloblastoma. [[H&E stain]].
| Synonyms  =
| Micro      = 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
| LMDDx      = [[adenomatoid odontogenic tumour]], [[ameloblastic fibroma]]
| Stains    =
| IHC        =
| EM        =
| Molecular  =
| IF        =
| Gross      =
| Grossing  =
| Site      = usu. mandible - see ''[[odontogenic tumours and cysts]]''
| Assdx      =
| Syndromes  =
| Clinicalhx =
| Signs      =
| Symptoms  =
| Prevalence = uncommon
| Bloodwork  =
| Rads      =
| Endoscopy  =
| Prognosis  =
| Other      =
| ClinDDx    = [[keratocytic odontogenic tumour]], odontogenic cysts
| Tx        =
}}
'''Ameloblastoma''' is an [[odontogenic cyst]].
'''Ameloblastoma''' is an [[odontogenic cyst]].



Revision as of 15:15, 23 February 2014

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 keratocytic odontogenic tumour, odontogenic cysts


Ameloblastoma is an odontogenic cyst.

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:

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.