Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2022  |  Volume : 49  |  Issue : 3  |  Page : 352-355

Ameloblastoma, a tumor with an infamous notoriety for recurrence

1 Department of Pathology, Jawaharlal Nehru Medical College, DMIMS (Deemed to be University), Wardha, Maharashtra, India
2 Gastroenterology, Jawaharlal Nehru Medical College, DMIMS (Deemed to be University), Wardha, Maharashtra, India

Date of Submission08-Jun-2022
Date of Acceptance09-Aug-2022
Date of Web Publication27-Dec-2022

Correspondence Address:
Dr. Miheer Milind Jagtap
Department of Pathology, Jawaharlal Nehru Medical College, DMIMS (Deemed to be University), Wardha, Maharashtra
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jss.jss_115_22

Rights and Permissions

Ameloblastoma is a locally invasive epithelial tumor of odontogenic origin comprising 1% or less of the cystic lesions and tumors arising in the jaws. It is a lesion most commonly seen in the molar region of the mandibular ramus. Ameloblastomas can be both benign and malignant and this can be differentiated by certain unique morphological features. In the older histology nomenclature, the term “adamantinoma” was used instead of ameloblastoma. The chances of recurrence can be high or low depending upon the surgical management. Curettages are associated with high recurrence rates while wide local excision tends to reduce recurrences.

Keywords: Adamantinoma, carcinoma, enamel, odontogenic, soap bubble appearance, treatment

How to cite this article:
Jagtap MM, Shukla S, Nair D. Ameloblastoma, a tumor with an infamous notoriety for recurrence. J Sci Soc 2022;49:352-5

How to cite this URL:
Jagtap MM, Shukla S, Nair D. Ameloblastoma, a tumor with an infamous notoriety for recurrence. J Sci Soc [serial online] 2022 [cited 2023 Jan 31];49:352-5. Available from: https://www.jscisociety.com/text.asp?2022/49/3/352/365166

  Introduction Top

Ameloblastoma is an odontogenic epithelial neoplasm. The origin of the word ameloblastoma can be found in the early English literature; “amel” means enamel and the Greek word “blastos” means germ. Postulated to be arising from the enamel organ, remnants of odontogenic cyst and the remains of Serres, ameloblastomas are locally aggressive tumors with a high propensity for recurrence.[1]

  Case Report Top

A 51-year-old female reported having visible swelling on the right side of her face since last 1 year with pain while eating for 2 months. Examination showed an ill-defined solitary swelling which was initially 2 cm × 2 cm × 1 cm in size and gradually progressed to the present size of 5 cm × 4.5 cm × 4 cm. No history of either trauma, toothache or discharge was present. The lesion was identified on radiological examination and surgically managed by hemi-mandibulectomy. Reconstruction was done simultaneously using iliac crest bone.

  Discussion Top

Ameloblastomas predominantly originate as benign tumors but rarely, they can evolve into or be associated with malignant transformation. The malignant counterpart is termed as “malignant ameloblastoma” or “ameloblastic carcinoma”[1] Previously known as “adamantinoma,” which was proposed by Malassez in 1885, this tumour's nomenclature has undergone various amendments.[2],[3]

The nomenclature of this tumor has undergone the following changes in the recent years:

  • The name “solid/multicystic ameloblastoma” was changed to “conventional ameloblastoma” in the WHO 2017 classification, 4th edition
  • The WHO 2017 classification, 4th edition recommended to use the term “desmoplastic ameloblastoma” as a variant of the conventional ameloblastoma
  • Metastasizing ameloblastoma was a term used in the WHO 2005 classification. It was removed from the classification of malignant odontogenic tumors and was reclassified as a benign odontogenic entity in the WHO 2017 classification.[4]

Considering the epidemiological aspects, this tumor is the most common odontogenic neoplasm equally affecting both the sexes from second to the seventh decade of life. The conventional variant aka intraosseous gnathic ameloblastoma predominantly affects the mandible and a small portion of the cases present with a maxillary presentation. Extraosseous ameloblastomas usually involve the gingiva and the retromolar area while other sites include the sinonasal tract, middle ear, temporal bone and the infratemporal fossa.[5]

The cells termed as ameloblasts are derived from the ectoderm and are seen only in the tooth development phase. They are involved in the deposition of enamel and become functionally potent only after the formation of dentin. Ameloblasts eventually are incorporated into the enamel epithelium and undergo programmed cell death by apoptosis after tooth eruption.

It has been documented that, genetic mutations interfere with the normal functioning of the mitogen activated protein kinase pathway and drive uncontrolled cellular proliferation.[6]

The diagnosis of ameloblastoma requires a three-pronged approach: Clinical, radiological and histopathological correlation. A definitive diagnosis of ameloblastoma is obtained by biopsy histological examination which is a gold standard.

Clinically, ameloblastomas are asymptomatic and are discovered incidentally on radiological examination. They are usually slow growing causing painless expansion of the jaw which causes malocclusion and loosening of teeth. Pain and hemorrhage can be present in the event of an infection. Patients with ameloblastomas usually present with hypercalcemia due to increased levels of parathyroid hormone related protein and excessive bone demineralization. Radiologically, ameloblastomas are characterized by soap bubble appearance and may appear unilocular or multilocular depending on the number of cystic cavities. They appear as radiographically dark (radiolucent) lesions involving the maxilla, mandible.

Clinically, ameloblastomas could be associated with nevoid basal cell carcinoma syndrome (Gorlin syndrome).[7] Grossly, ameloblastomas are characterized by presence of viscous mucoid fluid and a combination of solid and cystic spaces. Occasionally, ameloblastomas are associated with an impacted tooth and bony extension may be present [Figure 1].
Figure 1: Gross photograph of ameloblastoma with a solid cystic appearance. The cystic component shows the presence of semisolid and viscous hemorrhagic material

Click here to view

Histologically, ameloblastoma is classified into 6 types: follicular, plexiform, acanthomatous, granular cell, basal cell/basaloid, and desmoplastic. Microscopically, it shows islands and sheets of cells arranged in a basaloid or a follicular pattern. The outer layer shows tall columnar cells arranged in a palisaded pattern while the inner layer shows “stellate reticulum.” “Vickers Gorlin change” is a phenomenon characterised by the cells showing reverse polarisation away from the basement membrane [Figure 2], [Figure 3], [Figure 4], [Figure 5]. On immunohistochemistry, CD56, calretinin, BRAF V600E, beta catenin, FOXP1 and cytokeratin. On electron microscopy, tonofilaments, complex desmosomes, and lysosomal aggregates are seen.[8]
Figure 2: Section stained with routine hematoxylin and eosin (H and E) stain, low-power view (×10) shows basaloid arrangement of cells along with adjacent stroma. Two types of cell population are appreciated

Click here to view
Figure 3: Section stained with hematoxylin and eosin (H and E) stain, low power view (10x) shows cells arranged in a basaloid pattern with the cell nests showing hyperchromatic tumour cells arranged in a palidaded pattern. Cells with stellate reticulum are also seen in the center

Click here to view
Figure 4: Section stained with hematoxylin and eosin (H and E) stain, high power view (40x) shows a single tumour nest. There are hyperchromatic tumour cells arranged in a palisaded pattern in the periphery. The central part shows stellate reticulum like cells. Scant intervening fibrous stroma is seen with occassional chronic inflammatory cells

Click here to view
Figure 5: Section stained with routine hematoxylin and eosin (H and E) stain, high-power view (×40) shows a small nest of tumor cells with 2 cell populations: Cells in the periphery showing palisading arrangement and stellate reticulum cells in the center

Click here to view

It is of utmost importance that a benign ameloblastoma is distinguished from an ameloblastic carcinoma. These 2 disease entities have certain overlapping features like stellate reticulum cells, palisading in the periphery and reverse polarization. Ameloblastic carcinoma can be identified by the following morphological features: high mitotic activity, cellular atypia, perineural and vascular invasion, and nuclear pleomorphism.

The other differential diagnosis of ameloblastoma includes ameloblastic fibroma which is a benign mixed (epithelial–mesenchymal) tumor with nests of cuboidal to columnar cells with stellate reticulum and “prominent” basement membrane. Another differential is basal cell carcinoma and it can be identified by the presence of a desmoplastic stroma, prior history of skin cancer and mitotic activity. Other entities need to be ruled out like odontogenic keratocyst, odontogenic myxoma, and central giant-cell granuloma.[9]

Ameloblastomas treated with only curettage have a high tendency for recurrence while marginal resection with 1 cm margins is associated with reduced recurrence rates. Histological variants of ameloblastoma do not affect the prognosis. Ameloblastomas arising from the maxilla show high recurrence rates. Prognostic factors associated with high recurrence rate are tumors arising from the maxilla, BRAF V600E mutation, and tumors treated with simple curettage.[10]

  Conclusion Top

Considering this entity's notoriety for recurrence, a multidisciplinary approach becomes necessary to achieve the best outcome. Major surgeries in the facial area cause deforming esthetic changes due to which the role of oral maxillofacial and plastic surgeons in facial reconstruction becomes necessary. Similarly, expert speech language pathologists and voice therapists are vital for the voice management, odynophagia, and dysphagia issues arising after excision. Thus, an open line of communication between all the members has to be maintained so that best outcome is achieved through a collective interprofessional approach.

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

Mahmoud SA, Amer HW, Mohamed SI. Primary ameloblastic carcinoma: Literature review with case series. Pol J Pathol 2018;69:243-53.  Back to cited text no. 1
Ide F, Mishima K, Yamada H, Kikuchi K, Saito I, Kusama K. Intraosseous ameloblastoma with a prominent extraosseous component: Pitfalls in diagnosis. Head Neck Pathol 2010;4:192-7.  Back to cited text no. 2
Schafer DR, Thompson LD, Smith BC, Wenig BM. Primary ameloblastoma of the sinonasal tract: A clinicopathologic study of 24 cases. Cancer 1998;82:667-74.  Back to cited text no. 3
Wright JM, Vered M. Update from the 4th edition of the World Health Organisation Classification of Head and Neck Tumours: Odontogenic and Maxillofacial Bone Tumours. Head and Neck Pathol. 2017;11: 68-77.  Back to cited text no. 4
Palanisamy JC, Jenzer AC. Ameloblastoma. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545165/. [Last Updated on2022 Jan 21].  Back to cited text no. 5
Ruslin M, Hendra FN, Vojdani A, Hardjosantoso D, Gazali M, Tajrin A, et al. The epidemiology, treatment, and complication of ameloblastoma in East-Indonesia: 6 years retrospective study. Med Oral Patol Oral Cir Bucal 2018;23:e54-8.  Back to cited text no. 6
Medina A, Velasco Martinez I, McIntyre B, Chandran R. Ameloblastoma: Clinical presentation, multidisciplinary management and outcome. Case Reports Plast Surg Hand Surg 2021;8:27-36.  Back to cited text no. 7
Nakamura N, Mitsuyasu T, Higuchi Y, Sandra F, Ohishi M. Growth characteristics of ameloblastoma involving the inferior alveolar nerve: A clinical and histopathologic study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:557-62.  Back to cited text no. 8
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. 9
Hendra FN, Natsir Kalla DS, Van Cann EM, de Vet HCW, Helder MN, Forouzanfar T. Radical vs. conservative treatment of intraosseous ameloblastoma: Systematic review and meta-analysis. Oral Dis 2019;25:1683-96.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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

  In this article
Case Report
Article Figures

 Article Access Statistics
    PDF Downloaded21    
    Comments [Add]    

Recommend this journal