The IMC WIKI has moved...

... to the OREC-Library. To visit the OREC-Library please klick on the following link:


OREC-Library
fig. 1
Nur für registrierte Nutzer
fig. 2
Nur für registrierte Nutzer
fig. 3
Nur für registrierte Nutzer
fig. 4
Nur für registrierte Nutzer
fig. 5
Nur für registrierte Nutzer
fig. 6
Nur für registrierte Nutzer
fig. 7
Nur für registrierte Nutzer
fig. 8
Nur für registrierte Nutzer
fig. 9
Nur für registrierte Nutzer

| IMC Wiki | Ameloblastic tumours

Ameloblastic tumours

  • Home
  • Search
  • Articles alphabetically
  • Categories

<< back



WHO classification: Odontogenic epithelial tumours without odontogenic ectomesenchyme

The following tumours belong to this group:
ANZEIGE:
Logo IMC Uni Essen Duisburg
in Kooperation mit
Logo MVZ Kopfzentrum
Zahnimplantate,
Parodontosebehandlungen,
Aesthetische Zahnbehandlungen
zu sehr guten Konditionen
In der Praxis für Zahnmedizin im EKN Duisburg
Weitere Informationen unter www.mvz-kopfzentrum.de

Ameloblastoma

Synonyms: Adamantinoma, epithelial odontoma, adamantoblastoma, multilocular cys

Definition and clinical picture

Ameloblastoma is the most frequent odontogenic tumour (18%). Development from epithelial rests on the dental ridge and cell rests of Malassez, as well as the enamel organ; may also develop from an odontogenic cyst (follicular cyst, calcifying odontogenic cyst or keratocyst). No predilection for either sex; occurs mainly between the third and fourth decades of life. Occurs extremely rarely before the age of 18. Location: >75% of cases in the mandible, 50% of which occur in the molar and premolar regions. Histologically, this is a benign tumour; clinically, however, it is semi-malignant due to locally extremely aggressive infiltrating growth into marrow spaces; it tends to recur but hardly ever develops metastases.
Clinical features: Asymptomatic swelling, rarely loosening of teeth, pain or inflammation.

Malignant ameloblastoma, an odontogenic carcinoma, is very rare. Formation of metastasis in regional lymph nodes without significant changes to the underlying structure in the primary tumour.

Diagnosis / Histological findings

Radiology: Not pathognomonic; typically, unilocular or multilocular bubble-type or honeycomb-like osteolysis occurs. Root resorption, tooth displacement, and sometimes teeth within the lesion are possible.

#pic#
#pic#
#pic#
#pic#
Histology: Three main growth forms and variants without particular therapeutic or prognostic significance:

  • Follicular type
  • Plexiform type
  • Unicystic type (in younger patients)
    • luminal
    • intracystic
    • mural
  • Cellular variants with squamous epithelium (acanthomatous) metaplasia, granular cell metaplasia and basal cell metaplasia. Rarely: desmoplastic ameloblastoma with increased cellularity and less aggressive in the anterior maxilla.
  • Extra-osseous occurrence in the oral mucosa (peripheral ameloblastoma); in older patients the tendency to recur decreases.
Histological criteria for diagnosis:
  • Tumour cell compounds consisting of highly prismatic ameloblastoma cells
  • Peripheral palisade structure,
  • Subnuclear vacuoles
  • No formation of hard tissue
  • No proliferating stroma component
#pic#
#pic#
#pic#
#pic#
#pic#

Differential diagnosis

  • Ameloblastic fibroma
  • Adenomatoid odontogenic tumour
  • Odontogenic squamous cell tumour
  • Calcifying epithelial odontogenic tumour (Pindborg)
  • Giant cell granuloma
  • Carcinoma metastasis

Treatment and prognosis

  • Local, radical resection with a safety distance of at least 0.5 cm exceeding the macroscopic margin of the tumour
  • Immediate reconstruction, or
  • Bilateral primary reconstruction once the final histological diagnosis is made
Tendency to recur: up to 30% (approx.). Since approx. 50% of relapses occur within the first 5 years, follow-up is recommended for at least 10 years (initially more frequent, then annual, clinical and radiological control)

 back up

Squamous odontogenic tumour

Definition and clinical picture

This is a benign, locally invasive tumour consisting of complexes from mature squamous epithelium that are embedded in fibrous stroma. It occurs very rarely; adults are usually affected in their third decade; no predilection for either sex

Diagnosis / Histological findings

Radiological findings: Well-demarcated unilocular radioluceny

Histology: Lines and islets of differentiated squamous epithelium in stroma with only a few cells. No palisade structure of the basal cell layer, no atypia. Possibly degenerative cyst formation, calcification. Occasionally variants with light cells.

Differential diagnosis

Ameloblastoma
Primary intra-osseous squamous cell carcinoma

Treatment and prognosis

Excision
Occasional recurrence, individual blastomas are aggressive (wrong diagnosis?)

 back up

Calcifying epithelial odontogenic tumour

Synonym: Pindborg tumou

Definition and clinical picture

A very rare, locally aggressive though benign epithelial tumour with amyloid deposits that may calcify. It occurs between the ages of 30 and 60, with no predilection for either sex. Location: 60% in the mandible, 30% in the maxilla; it occurs most frequently in the premolar region and is often associated with an impacted tooth. Rarely also extra-osseous. Clinically: usually asymptomatic swelling, often only detected on the radiograph by calcified shadows

Diagnosis / Histological findings

Radiology: Well defined osteolysis, often around the crown of an impacted molar. Large foci may appear multilobular.

Histology: The tumour consists of islets and rows of small odontogenic epithelia in stroma with few cells. The epithelial cells are often clearly pleomorphic, sometimes they are multinucleate, with mitosis being rare. Foci of calcification, varying in size, and intra-cellular and extra-cellular amyloid deposits with surrounding foreign-body reaction and formation of granulation tissue.

Differential diagnosis

Calcifying odontogenic cyst
Odontogenic fibroma
Carcinoma metastasis

Treatment and prognosis

Very wide excision; long-term follow up
Recurs only rarely

 back up

Clear-cell odontogenic tumour

Definition and clinical picture

Clear-cell odontogenic tumours are rare, locally invasive odontogenic tumours. They occur between the fifth and seventh decades of life, with a prevalence in women, and mostly in the mandible. Locally, they show more aggressive growth than ameloblastoma

Diagnosis / Histological findings

Histology: Complexes of islet-type uniform vacuolised cells with light cytoplasma (glycogen) of varying size. Only sparse fibrous stroma

Differential diagnosis

Clear-cell adenoma
Clear-cell odontogenic carcinoma

Treatment and prognosis

Segmental resection (as with ameloblastoma)
High rate of recurrence
Long post-operative follow-up

 back up


sources

  • Horch, H. H. (o.J.)   Mund-Kiefer-Gesichtschirurgie 1   Praxis der Zahnheilkunde 10,1
  • Morgenroth K, Philippou S (1998)   Oralpathologie II; Zahnsystem und Kiefer in der Reihe von Spezielle pathologische Anatomie   Springer, Berlin - Heidelberg - New York
  • Philipsen HP, Reichart PA (1998)   Unicystic ameloblastoma. A review of 193 cases from the literature   Oral Oncol. 1998 Sep;34(5):317-25
  • Philipsen HP, Reichart PA, Nikai H, Takata T, Kudo Y (2001)   Peripheral ameloblastoma: biological profile based on 160 cases from the literature   Oral Oncol. 2001 Jan;37(1):17-27
  • Pindborg JJ (1958)   A calcifying epithelial odontogenic tumour   Cancer. 1958 Jul-Aug;11(4):838-43
  • Reichart PA, Philipsen HP (1999)   Oralpathologie. Farbatlanten der Zahnmedizin 14   Georg Thieme Verlag, Stuttgart, New York
  • Reichart PA, Philipsen HP, Sonner S (1995)   Ameloblastoma: biological profile of 3677 cases   Eur J Cancer B Oral Oncol. 1995 Mar;31B(2):86-99