Contemporary Clinical Dentistry
  Home | About us | Editorial board | Search
Ahead of print | Current Issue | Archives | Advertise
Instructions | Online submission| Contact us | Subscribe |


Login  | Users Online: 1180  Print this pageEmail this pageSmall font sizeDefault font sizeIncrease font size 

 Table of Contents  
Year : 2018  |  Volume : 9  |  Issue : 4  |  Page : 656-658  

Highly proliferative ameloblastic fibroma: A rare entity

1 Department of Oral and Maxillofacial Surgery, Vasantdada Patil Dental College and Hospital, Sangli, Maharashtra, India
2 Dental Surgeon, Shah Dental and Orofacial Center, Sangli, Maharashtra, India
3 Department of Oral Pathology and Microbiology, Bharati Vidyapeeth Deemed University Dental College and Hospital, Sangli, Maharashtra, India
4 Department of Orthodontics, Bharati Vidyapeeth Deemed University Dental College and Hospital, Sangli, Maharashtra, India

Date of Web Publication6-Nov-2019

Correspondence Address:
Dr. Sagar J Shah
Dental Surgeon, Shah Dental and Orofacial Center, Kuber Chambers, Harbot Road, Sangli - 416 416, Maharashtra
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ccd.ccd_637_18

Rights and Permissions

Ameloblastic fibroma (AF) is a rare odontogenic neoplasm which is commonly seen in the second decade of life. It is seen most frequently in the mandibular posterior region. AF shows clinical and radiographic resemblance with other commonly occurring odontogenic cyst and tumors. Histopathologically, it shows great resemblance with primitive dental papilla. Immunohistochemistry helps in understanding the nature and proliferative potential of tumor and helps in proper treatment planning. Large lesions and recurrent lesions are treated with segmental resection which can often lead to morbidity, especially in young patients if not managed properly. Herein, we present a case of a large AF in the posterior mandible region in a 21-year-old female patient with significant expansion and erosion of cortical plates and lower border of the mandible with a high Ki67 proliferative index (20%) which was surgically treated by segmental resection and immediate reconstruction by autogenous iliac graft.

Keywords: Immunohistochemistry, mandibular reconstruction, neoplasm, therapeutic use

How to cite this article:
Sanadi A, Shah SJ, Golgire S, Shetti S. Highly proliferative ameloblastic fibroma: A rare entity. Contemp Clin Dent 2018;9:656-8

How to cite this URL:
Sanadi A, Shah SJ, Golgire S, Shetti S. Highly proliferative ameloblastic fibroma: A rare entity. Contemp Clin Dent [serial online] 2018 [cited 2020 Aug 8];9:656-8. Available from:

   Introduction Top

The WHO defined ameloblastic fibroma (AF) in 2005 as “Neoplasm consisting of odontogenic ectomesenchyme resembling the dental papilla and epithelial strands and nests resembling dental lamina and enamel organ. No dental hard tissues are present.”[1] It was first described in literature in 1891 by Kruse.[2] In 1971, AF was first classified as benign neoplasm, and in 1992, the WHO classified it as mixed neoplasm.[3],[4] AF is relatively uncommon neoplasm consisting of 1.5%–4.5% of all the odontogenic tumors occurring frequently in the second decade of life.[3],[4] Some believe AF to be a slow-growing innocuous tumor while some suggest it to be more aggressive tumor which may be a part of a spectrum of lesions which mature from AF to ameloblastic fibro-odontoma to odontoma.[5],[6] The present case highlights the importance of careful diagnosis of intrabony oral lesion in a young patient and usage of immunohistochemistry (IHC) in understanding the nature of tumor and selecting appropriate treatment option.

   Case Report Top

A 21-year-old female reported to the hospital with a history of asymptomatic progressive facial swelling for 1 month. Extraorally, slight facial asymmetry was noted on the left side [Figure 1]a. Intraoral examination revealed hard, diffuse swelling in the mandibular body from second premolar to second molar region with expansion of buccal and lingual cortical plate covered by normal mucosa [Figure 1]b and [Figure 1]c. No paresthesia or pain associated with the swelling. The panoramic radiograph showed the presence of a well-defined multilocular radiolucency involving the left mandible with root resorption of the teeth. A cone-beam computed tomography scan showed an expansive lesion with 8.0 cm × 3.0 cm × 4.5 × cm in extension causing loss and buccal and lingual cortical plates and invasion of lesion in the mandibular canal and lower border of mandible in the molar region [Figure 1]d and [Figure 1]e.
Figure 1: Clinical and cone-beam computed tomography images. (a) Preoperative frontal image of a patient showing mild facial asymmetry on the left side. (b) Intraoral image showing swelling in the lingual region with respect to 44, 45. (c) Intraoral image of the buccal vestibule showing obliteration of the left buccal vestibule in the molar region. (d) Transverse cone-beam computed tomography section of the mandible at mid-root region showing extensive bone expansion and perforation of buccal and lingual cortical plates. (e) Three-dimensional reconstructed image of buccal aspect of the mandible showing invasion of inferior alveolar canal and loss of cortical plates

Click here to view

Following incisional biopsy, the specimen was sent to histological examination. Microscopically, ameloblastomatous islands were noted with central stellate reticulum cells enmeshed in fibrocollagenous stroma which resembled primitive dental papilla. Proliferating odontogenic epithelium cells from the discrete island exactly resembled with the follicular stage of dental papilla with centrally placed stellate reticulum cells. Connective tissue mesenchyme consisted of plump stellate and ovoid cells in loose matrix [Figure 2].
Figure 2: Histopathological examination. (a) Histopathological image showing ameloblastic islands in cellular connective tissue stroma. (b) ×4 view. (c) ×10 view. (d) Tall columnar cells with reversal of polarity resembling primitive odontogenic epithelium

Click here to view

The diagnosis of AF was established. Despite being locally aggressive, considering the high possibility of recurrence, segmental resection of the mandible with a 1 cm safe margin was done to obtain a good prognosis. The inferior alveolar nerve was preserved and immediate reconstruction with autologous iliac crest bone graft and 2.5 mm reconstruction plates and bicortical screws was done [Figure 3].
Figure 3: Surgical treatment. (a) Lingual expansion of the mandibular body in the posterior region. (b) Submandibular approach for segmental resection showing the lingual expansive lesion and loss of lower border of the mandible. (c) Osteotomy of mandible while preserving inferior alveolar nerve. (d) Immediate reconstruction of the defect using autogenous iliac crest and reconstruction plate

Click here to view

   Discussion Top

AF is rare neoplasm of adolescence commonly seen in the second decade of life. AF has slight predilection for males with male-to-female ratio of 1.2:1–1.4:1. The posterior mandible is the most common site of occurrence of AF (80%). Interestingly, most of the lesions in the anterior region are seen in the maxilla, and most lesions in the posterior region are seen in the mandible.[3],[4],[7]

AF is seldom symptomatic and usually presented as a hard swelling with intact overlying mucosa. AF exhibits slightly slower growth than simple ameloblastoma and does not infiltrate among trabeculae of bone; instead, it enlarges by gradual expansion leaving the periphery of the lesion smooth.[8] Radiographically, it resembles other odontogenic tumors. Multilocular radiolucency is most common (75%) and are seen in association with large lesions. Occasionally, it can cause root resorption of erupted teeth and bony perforation of cortical plates is also noted.[4] Similar clinical and radiographic findings were found in our case.

Microscopically, AFs are composed of neoplastic epithelial and connective tissue components. The epithelial component resembles embryonic dental lamina which consists of islands and cords of odontogenic epithelium with two or three layers of cuboidal cells and small nests or islands of cells with scanty cytoplasm while larger nests show stellate reticulum-like cells. The mesenchymal component of AF closely resembles the fibromyxoid tissue of primitive the dental papilla characterized by plump fibroblasts and delicate collagen fibrils.[8],[9] If enamel or dentin is noted histologically, they are classified as ameloblastic fibro-odontoma and ameloblastic fibrodentinoma, respectively.[10]

The differential diagnosis of AF includes odontogenic cyst and tumors such as dentigerous cyst, ameloblastoma, odontogenic keratocyst, myxoma, and other mixed tumors.[8] Although these lesions show many overlapping characters, it is crucial to differentiate AF from other mixed odontogenic tumors owing to its true neoplastic potential, malignant transformation potential, and possibility of recurrence.[8],[11]

Assessment of the proliferative potential of AF using immunohistochemical markers helps in understanding of tumor aggressiveness and facilitates adequate surgical planning.[12] In the present case, ameloblastic epithelium was strongly immunoreactive for CK 5 and 6/CK 14 with focal central immunopositivity in stellate reticulum for calretinin. The Ki67 proliferative index in fibromatous component was around 20% [Figure 4]. In regard with high Ki67 index, higher chances of recurrence are possible, thus long follow-up is imperative.[13]
Figure 4: Immunohistochemical analysis. (a) Immunohistochemical analysis showing highly proliferative neoplastic epithelium for Ki67. (b) Immunohistochemical analysis showing strong immunoreactivity for CK 14. (c) Immunohistochemical analysis showing strong immunoreactivity for CK 5 and 6. (d) Immunohistochemical analysis showing focal central immunopositivity in stellate reticulum for calretinin

Click here to view

AF has a tendency for recurrence and different recurrence rates have been reported in literature ranging from 16.3% to 33.3%.[3],[4],[6] The rate of malignant transformation ranges from 6.4% to 11.4% in various studies.[3],[4],[6] Interestingly, most of the malignant transformations are seen in older age group and most of recurrences are noted in younger age group.[14]

The appropriate treatment for AF continues to be a topic of debate. Some authors suggest treatment of smaller lesions with conservative treatment such as enucleation and curettage to limit the disability caused by more extensive procedures. It is suggested that an extensive approach of marginal or segmental resection should be considered in patients with extensive multilocular lesions and recurrent cases.[14] In the present case, owing to large multiocular lesion in a young patient with high Ki67 index, segmental resection with safe margin of 1cm followed by immediate reconstruction with autogenous iliac crest graft was done. The follow-up of patient was done at 1 week, 3 weeks, 3 months, and thereafter at 6 months interval for 15 months, no signs of recurrence or malignant transformation were seen.

   Conclusion Top

AF is a rare odontogenic neoplasm which shows overlapping clinical and radiographic characters with other odontogenic tumors. It relatively occurs in young age group and has potential for recurrence and malignant proliferation. IHC studies help in understanding the nature and proliferation of such tumors. Appropriate surgical modality should be followed owing to its chances of recurrence and malignant transformation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Barnes L, Eveson JW, Reichart P, Sidransky D. World Health Organization Classification of Tumours. Pathology and Genetics Head and Neck Tumours. Lyon: IARC Press; 2005.  Back to cited text no. 1
Kruse A. On the development of cystic tumors in the mandible. Arch Pathol Anat 1891;124:137-48.  Back to cited text no. 2
Chen Y, Wang JM, Li TJ. Ameloblastic fibroma: A review of published studies with special reference to its nature and biological behavior. Oral Oncol 2007;43:960-9.  Back to cited text no. 3
Buchner A, Vered M. Ameloblastic fibroma: A stage in the development of a hamartomatous odontoma or a true neoplasm? Critical analysis of 162 previously reported cases plus 10 new cases. Oral Surg Oral Med Oral Pathol Oral Radiol 2013;116:598-606.  Back to cited text no. 4
Reichart PA, Philipsen HP, editors. Odontogenic Tumors and Allied Lesions. London, England: Quintessence; 2004. p. 117-28.  Back to cited text no. 5
Slootweg PJ. An analysis of the interrelationship of the mixed odontogenic tumors – Ameloblastic fibroma, ameloblastic fibro-odontoma, and the odontomas. Oral Surg Oral Med Oral Pathol 1981;51:266-76.  Back to cited text no. 6
Adebayo ET, Ajike SO, Adekeye EO. A review of 318 odontogenic tumors in Kaduna, Nigeria. J Oral Maxillofac Surg 2005;63:811-9.  Back to cited text no. 7
Vij R, Vij H. Ameloblastic fibroma: An uncommon entity. BMJ Case Rep 2013;2013. pii: bcr2013010279.  Back to cited text no. 8
Takeda Y. Ameloblastic fibroma and related lesions: Current pathologic concept. Oral Oncol 1999;35:535-40.  Back to cited text no. 9
Couch RD, Morris EE, Vellios F. Granular cell ameloblastic fbroma. Am J Clin Pathol 1962;27:398-404.  Back to cited text no. 10
Ealla KK, Basavanapalli VR, Velidandla SR, Manikya S, Ragulakollu R, Danappanavar PM, et al. Ameloblastic fibroma of the maxilla with bilateral presentation: Report of a rare case with review of the literature. Case Rep Pediatr 2015;2015:250713.  Back to cited text no. 11
Rao SP, Srivastava G, Smitha B. Ameloblastic fibroma. J Oral Maxillofac Pathol 2012;16:444-5.  Back to cited text no. 12
Sano K, Yoshida S, Ninomiya H, Ikeda H, Ueno K, Sekine J, et al. Assessment of growth potential by MIB-1 immunohistochemistry in ameloblastic fibroma and related lesions of the jaws compared with ameloblastic fibrosarcoma. J Oral Pathol Med 1998;27:59-63.  Back to cited text no. 13
Tozoglu S, Hatipoglu M, Aytekin Z, Gurer EI. Extensive ameloblastic fibroma of the mandibula in a female adult patient: A case report with a follow-up of 3 years. Eur J Dent 2016;10:139-43.  Back to cited text no. 14
[PUBMED]  [Full text]  


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Add to My List *
* Registration required (free)  

  In this article
   Case Report
    Article Figures

 Article Access Statistics
    PDF Downloaded69    
    Comments [Add]    

Recommend this journal