|Year : 2020 | Volume
| Issue : 2 | Page : 69-71
Ameloblastic fibro-odontoma of mandible
Nihal Ibrahim Mirza1, Sohaila Fatima2
1 Department of Laboratory Medicine, Aseer Central Hospital, Abha, KSA
2 Department of Pathology, King Khalid University, Abha, KSA
|Date of Submission||05-Jul-2020|
|Date of Acceptance||16-Jul-2020|
|Date of Web Publication||31-Oct-2020|
Dr. Sohaila Fatima
Department of Pathology, King Khalid University, Abha
Source of Support: None, Conflict of Interest: None
Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor. It is considered under the category of ameloblastic fibroma which is believed to be a true mixed tumor, in which both the epithelial and the ectomesenchymal elements are neoplastic in the latest World Health Organization classification. We present a case of 10-year-old male with a left mandibular mass which was diagnosed as AFO due to its characteristic histology.
Keywords: Ameloblastic fibro-odontoma, mandible, odontogenic tumor
|How to cite this article:|
Mirza NI, Fatima S. Ameloblastic fibro-odontoma of mandible. Indian J Oral Health Res 2020;6:69-71
| Introduction|| |
Ameloblastic fibroma (AF) is a benign, true mixed tumor composed of odontogenic mesenchyme resembling dental papilla and epithelial tissue resembling odontogenic epithelium, in which no dental hard tissues are present. AF is a rare tumor and its relative frequency within the group of odontogenic tumors ranges from 0% to 3.4%. Ameloblastic fibro-odontoma (AFO) is a tumor which has the histologic features of AF in conjunction with the presence of dentin and enamel. This study reports a case of AFO of the mandible in a 10-year-old male patient.
| Case Report|| |
A 10-year-old boy presented to ear, nose, throat department with a mass on the left side of mandible. A diffuse swelling was seen in the left body of mandible with firm consistency and ill-defined margins. Oral panoramic radiograph showed a radiopaque mass with radiolucent foci in the left posterior mandible extending from second molar to the mandibular ramus. The patient underwent excisional biopsy of the lesion under general anesthesia. Gross examination revealed fragmented pieces of bone and firm tissue measuring 4 cm × 3.5 cm × 1.4 cm. The microscopy revealed fragments of immature connective tissue reminiscent of dental papilla with cords and small islands of cuboidal to columnar odontogenic epithelial cells. Irregular masses of dental hard tissue composed of enamel matrix and dentin were also seen [Figure 1] and [Figure 2] and a diagnosis was of AFO was made. The patient is currently on follow-up and is doing well.
|Figure 1: Section showing fragments of immature connective tissue reminiscent of dental papilla with cords and small islands of odontogenic epithelial cells. Irregular masses of dental hard tissue composed of enamel matrix and dentin are also seen (H and E, ×10)|
Click here to view
|Figure 2: (a) Section showing immature connective tissue with cords and small islands of cuboidal to columnar odontogenic epithelial cells. (b) Section showing dental tissue composed of enamel matrix and dentin (H and E, ×20)|
Click here to view
| Discussion|| |
The term AFO was first used by Hooker in 1967. AFOs had originally been termed ameloblastic odontomas but in 1971 World Health Organization (WHO) suggested that this term is inappropriate since it encompasses two types of odontogenic tumors that share a different histology and biologic behavior. Lesions having a composition similar to AF, but also showing inductive changes leading to the deposition of dentine alone, or dentine plus enamel, are termed ameloblastic fibrodentinoma (AFD) and AFO, respectively. It is not clear whether the AF, AFD, and AFO should be regarded as separate entities or as stages in the evolution of a single type of lesion, and there may be merit in continuing to separate them until more experience of their behavior has been accumulated, however from 2005 WHO has considered AFO to be a variant of AF. It was suggested that tumors presenting a histopathological combination of AF and a complex odontoma that is biologically noninvasive be termed AFOs, and those that histopathologically represent a combination of ameloblastoma and complex odontoma and behave in an invasive manner, like the classical ameloblastoma be termed odontoameloblastoma. Few studies suggested that AFD should be considered a separate entity and was not included in their analysis of AFOs.,
In the latest WHO classification, AFO has been included in AF.
AFO represents 0.3%–1.7% of all odontogenic tumors and 4.6% of cases in children. The mean age of presentation is between 8 and 12 years. There is no gender or anatomic site predilection. In a study, the patient's age ranged from 8 months to 26 years (mean 9.6, median 9.0). Most of the cases (71%) were diagnosed in patients between 5 and 14 years of age, and only 4.3% cases were diagnosed in patients older than 20 years. There were 74 (65%) males and 40 (35%) females, with a male-to-female ratio of 1.85:1. Lesions were located in the mandible in 74 (65%) cases and in the maxilla in 40 (35%), with a mandible-to-maxilla ratio of 1.85:1. The most common clinical presentations of AFO are asymptomatic swelling and failure of tooth eruption. In our case, there was painless swelling in mandibular region.
On the basis of histopathological features, it is not possible to distinguish between AFs (true neoplasms) and early-stage odontomas before they differentiate and mature. However, rare AFs show formation of dental hard tissues and reach an exceptional size. These lesions have been referred to as AFD and AFO but are most likely developing odontomas. A study also suggests that AFOs are hamartomatous in nature representing a stage that precedes the complex odontoma. The analysis of the literature revealed that lesions that exhibit aggressive growth, causing considerable facial deformity and bone destruction, probably represent true neoplasms, while others that are small, asymptomatic and have no bony expansion probably represent developing odontomas (hamartomas).
Radiographically AFO presents as a unilocular or multilocular lesion. They may appear as a radiolucent area that consists of the variable amount of calcified material. The ratio of radiopaque to radiolucent areas differs from one lesion to another sometimes the mineralized elements in the tumor predominate and the lesion may be radiographically similar to that of an odontoma.
Microscopically, it is composed of strands and buds of ameloblastic epithelial cells usually cuboidal and two cell layers thick embedded in a cellular myxoid connective tissue stroma. The presence of this mesenchymal component is the main distinguishing feature with ameloblastoma. Hard tooth structures such as dentin and enamel are present. Thus, it consists of an AF with areas resembling small odontomas. The differential diagnosis of AFO is ameloblastoma, odontogenic myxoma, dentigerous cyst, odontogenic keratocyst, central giant cell granuloma, histocytosis-X group of lesions, calcifying odontogenic cyst, calcifying epithelial odontogenic tumor, adenomatoid odontogenic tumor, and immature odontoma.
The treatment of AFO is associated with conservative surgical approach. Sporadic recurrences have been attributed to inadequate surgical removal at the time of initial treatment. There is a controversy in the literature regarding extraction or retaining the associated tooth bud in the case of AFO. Majority of the articles state that the associated tooth bud has to be removed to avoid recurrence. The prognosis is excellent and recurrences have been rarely described.
In conclusion, AFO is a rare benign mixed odontogenic tumor which has been included in AF category in the latest WHO classification. It usually affects children and surgical resection is the main modality of treatment with an excellent prognosis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Muller S, Vered M. Ameloblastic fibroma. In: EI-Naggar AK, Chan JK, Grandis JR, Takata T, Slootweg PJ, editors. WHO Classification of Head and Neck Tumours. International Agency for Research on Cancer; 2017. p. 223-4.
Buchner A, Merrell PW, Carpenter WM. Relative frequency of central odontogenic tumors: a study of 1,088 cases from Northern California and comparison to studies from other parts of the world. J Oral Maxillofac Surg 2006;64:1343-52.
Takeda Y, Tomich CE. Ameloblastic fibro-odontoma. In: Barnes L, Eveson JW, Reichart P, Sidransky D, editors. Pathology and Genetics of Head and Neck Tumours. Lyon: IARC Press; 2005.
Hooker SP. Ameloblastic odontoma: Analysis of twenty six cases. Oral Surg 1967;24:375.
Pindborg JJ, Kramer IR. Histological Typing of Odontogenic Tumours, Jaws Cysts, and Allied Lesions. Geneva: World Health Organization; 1971.
Kramer IR, Pindborg JJ, Shear M. The World Health Organization histological typing of odontogenic tumours. Introducing the second edition. Eur J Cancer B Oral Oncol 1993;29B: 169-71.
Reichart PA, Philipsen HP. Odontogenic Tumors and Allied Lesions. London: Quintessence; 2004.
Praetorius F. Odontogenic tumors. In: Barnes L. Surgical Pathology of the Head and Neck. 3rd
ed. India: Informa; 2009.
Guerrisi M, Piloni MJ, Keszler A. Odontogenic tumors in children and adolescents. A 15-year retrospective study in Argentina. Med Oral Patol Oral Cir Bucal 2007;12:E180-5.
Buchner A, Kaffe I, Vered M. Clinical and radiological profile of ameloblastic fibro-odontoma: an update on an uncommon odontogenic tumor based on a critical analysis of 114 cases. Head Neck Pathol 2013;7:54-63.
Chen Y, Li TJ, Gao Y, Yu SF. Ameloblastic fibroma and related lesions: A clinicopathologic study with reference to their nature and interrelationship. J Oral Pathol Med 2005;34:588-95.
Rosai J, Ackerman L. Surgical Pathology. 11th
ed. New York: Mosby; 2017.
Surej Kumar LK, Manuel S, Khalam SA, Venugopal K, Sivakumar TT, Issac J. Ameloblastic fibro-odontoma. Int J Surg Case Rep 2014;5:1142-4.
[Figure 1], [Figure 2]