Mandible / maxilla
Benign tumors / tumor-like conditions
Odontogenic fibroma

Author: Anthony Martinez, M.D.(see Authors page)
Editor: Kelly Magliocca, D.D.S., M.P.H.

Revised: 21 June 2018, last major update February 2018

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Odontogenic fibroma maxilla [title] pathology

Cite this page: Martinez, A. Benign tumors / tumor-like conditions: odontogenic fibroma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mandiblemaxillaodontogenicfibroma.html. Accessed September 22nd, 2018.
Definition / general
  • Rare, benign mesenchymal odontogenic tumor composed of mature fibrous tissue with variable amounts of inactive appearing odontogenic epithelium
    • Calcification may be present
  • Two common variants:
    • Intraosseous or central odontogenic fibroma
    • Extraosseous or peripheral odontogenic fibroma, centered in gingival tissues associated with tooth bearing regions of jaws
  • Rare variants (see Microscopic (histologic) description below)
Essential features
  • Strands or nests of odontogenic epithelium, with or without calcification, set in a variably cellular fibrocollagenous stroma
Terminology
  • Odontogenic fibroma
  • Central odontogenic fibroma
  • Peripheral odontogenic fibroma
Epidemiology
Sites
  • Mandible and maxilla affected equally
  • Peripheral odontogenic fibroma
    • More common along anterior gingival region
  • Central odontogenic fibroma
    • Most involving mandible are posterior to first molar
    • Most involving maxilla are anterior to first molar
Clinical features
  • Can be asymptomatic
  • If symptomatic, can present with swelling and pain
Diagnosis
  • Diagnosis dependent on clinical, radiologic and pathologic correlation
Radiology description
  • Can present as a unilocular or multilocular radiolucency with distinct borders
  • Root resorption and displacement of teeth have been reported
  • ~10% exhibit radiopaque flakes that correlate with calcification
Radiology images

Images hosted on other servers:
Missing Image

IOPA showing irregular radiopaque masses

Missing Image

Multilocular radiolucency near 21, 22, 63, 24 and 25

Prognostic factors
Case reports
Treatment
  • Peripheral odontogenic fibromas are usually treated by excision
  • Central odontogenic fibromas are usually treated by enucleation and curettage
Clinical images

Images hosted on other servers:
Missing Image Missing Image

Gingival masses

Gross images

Images hosted on other servers:
Missing Image

Surgical intervention of odontogenic fibroma

Microscopic (histologic) description
  • Consists of variably cellular fibrocollagenous tissue with scattered, small, inactive odontogenic epithelium in strands, cords or nests
    • Calcification can be seen in association with odontogenic epithelium and when extensive could consider classification as ossifying variant of odontogenic fibroma
  • Rare Variants and Associations:
    • Ossifying variant of odontogenic fibroma: epithelial odontogenic islands intimately admixed with bone trabeculae (see Fig. 8 below)
    • Granular cell odontogenic fibroma: variant characterized by granular cell appearance within the odontogenic epithelium or stromal granular cells
    • Central odontogenic fibroma (COF) with amyloid-like protein deposition
      • Characteristic COF with ovoid or globular acellular hyalinized structures and possible areas of periepithelial amyloid deposition (cuffing)
      • Deposits positive for Congo red and demonstrated green birefringence under polarized light examination
      • A positive immunohistochemical reaction pattern employing antibodies to odontogenic ameloblast associated protein (ODAM) confirmed that this protein is, in fact, odontogenic amyloid, as found in developing tooth germs (see Fig. 9 below)
    • Central odontogenic fibroma associated with central giant cell granuloma (CGCG)
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Kelly Magliocca, D.D.S., M.P.H.
Missing Image Missing Image

Case 1: Odontogenic fibroma with extensive calcification - 6x and 20x

Missing Image Missing Image

Case 2: Odontogenic fibroma with giant cell reaction/giant cell granuloma


Missing Image Missing Image Missing Image Missing Image

Case 3: Odontogenic fibroma - 6x, 8x, 15x and 20x



Images hosted on other servers:
Missing Image

Odontogenic fibroma of the maxilla

Missing Image

COF and dentigerous cyst in the maxilla

Missing Image Missing Image

Islands of odontogenic epithelium within a cellular fibrous stroma

Missing Image

Features of peripheral odontogenic fibroma

Missing Image

Fig. 7 Odontogenic fibroma with central giant cell lesion


Missing Image

Fig. 8 Ossifying variant of COF

Missing Image

Fig. 9 Amyloid variant of COF

Positive stains
Differential diagnosis
    Central odontogenic fibroma
  • Ameloblastic fibroma
    • Composed of odontogenic epithelial component strands, cords and islands that may exhibit peripheral palisading, reverse polarization and stellate reticulum
    • Primitive appearing stroma that is delicate and lobular in appearance
  • Desmoplastic fibroma
    • Composed of fascicles of variably SMA positive myofibroblasts
    • Consider desmoid tumor of bone
  • Hyperplastic dental follicles with odontogenic fibroma-like islands
  • Odontogenic myxoma
    • Spindled to stellate cells with eosinophilic cytoplasm set in myxoid matrix
    • Binucleated "heart shaped" cells, mitoses and minimal atypia can be seen
    • If abundant collagen is present, the term myxofibroma or fibromyxoma has been used
    • Occasional scattered epithelial rests can be seen
  • Sclerosing odontogenic carcinoma
    • Rare, primary intraosseous carcinoma of the jaws with bland cytology, markedly sclerotic stroma and aggressive pattern of infiltration
    • Single file thin cords, nests and strands of epithelium in a densely sclerotic stroma
    • Epithelium or stroma may dominate in different areas
    • Epithelium may be so compressed so as to be best seen with immunohistochemistry (such as cytokeratin AE1 / 3)
    • Cytologically, individual epithelial cells are bland with uncommon mitoses
    • Cytoplasm may show vacuolation or partial clearing
    • Despite the bland cytological appearance, there is invasion of skeletal muscle and commonly, perineural invasion

Peripheral odontogenic fibroma
  • Irritation fibroma
    • Nodular lesion with a dermal proliferation of haphazard collagen bundles in response to local irritation
  • Peripheral giant cell granuloma
    • Proliferation of multinucleated giant cells, plump oval mononuclear cells and hemorrhage
    • Has similar appearance to solid aneurysmal bone cyst but without USP6 rearrangements
  • Pyogenic granuloma (lobular capillary hemangioma)
    • Lobular proliferation of well formed, small capillary vascular channels with larger, feeder vessels
    • Can show ulceration
Board review question #1
    A mandibular mass that is radiolucent by plain radiograph, is characterized by strands or nests of inactive appearing odontogenic epithelium, with or without calcification, set in a variably cellular fibrocollagenous stroma.

    Which of following is the best diagnosis?

  1. Central odontogenic fibroma
  2. Desmoplastic fibroma
  3. Odontogenic myxoma
  4. None of the above
Board review answer #1
A. Central odontogenic fibroma