Journal of Dr. NTR University of Health Sciences

CASE REPORT
Year
: 2018  |  Volume : 7  |  Issue : 4  |  Page : 281--284

Ameloblastic fibro-odontoma or complex adontoma: A diagnostic dilemma?


K Vinay Kumar Reddy1, Kotya Naik Maloth1, Modali Venkata Lakshmi1, Moni Thakur2,  
1 Department of Oral Medicine and Radiology, Mamata Dental College and Hospital, Khammam, Telangana, India
2 Department of Oral Pathology and Microbiology, Mamata Dental College and Hospital, Khammam, Telangana, India

Correspondence Address:
Dr. Kotya Naik Maloth
Department of Oral Medicine and Radiology, Mamata Dental College and Hospital, Giriprasad Nagar, Khammam - 507 002, Telangana
India

Abstract

Ameloblastic fibro-odontoma is a rare benign mixed odontogenic tumor exhibiting the histologic characteristics of ameloblastic fibroma and complex odontoma. Clinically, it represents a well-defined asymptomatic swelling with deformity of face, and radiographically a well-defined radiolucent area, which contains radiopaque foci of various sizes and shapes. These features overlap with other lesions such as calcifying odontogenic cyst, calcifying epithelial odontogenic tumor, and adenomatoid odontogenic tumor which makes a diagnostic dilemma for oral clinicians. Hereby we report such a rare case in a 7-year-old boy.



How to cite this article:
Reddy K V, Maloth KN, Lakshmi MV, Thakur M. Ameloblastic fibro-odontoma or complex adontoma: A diagnostic dilemma?.J NTR Univ Health Sci 2018;7:281-284


How to cite this URL:
Reddy K V, Maloth KN, Lakshmi MV, Thakur M. Ameloblastic fibro-odontoma or complex adontoma: A diagnostic dilemma?. J NTR Univ Health Sci [serial online] 2018 [cited 2019 Jun 16 ];7:281-284
Available from: http://www.jdrntruhs.org/text.asp?2018/7/4/281/249830


Full Text



 Introduction



Ameloblastic fibro-odontoma (AFO) is a rare benign mixed odontogenic tumor, defined by the World Health Organization (WHO) as “a neoplasm composed of proliferating odontogenic epithelium in a cellular ectomesenchymal tissue with varying degrees of inductive changes and dental hard tissue formation.”[1],[2] It is characterized by a well-defined, slow-growing, and expansible asymptomatic swelling usually detected as a result of failure of tooth eruption.[3] The frequency of occurrences reported was 1%–3%.[4] Hereby we report such a rare case of AFO in a 7-year-old boy.

 Case Report



A 7-year-old boy reported to the department with a complaint of swelling on the right side of the face since 2 months [Figure 1]. The patient was apparently normal 2 months back; later he noticed a swelling which was small in size which gradually increased to attain the present size. The swelling was not associated with any pain and discharge. Dental and medical history was noncontributory. On extraoral examination, a diffuse swelling was noted on the right side of the mandible in the posterior region, which was hard in consistency and nontender. On intraoral examination, a well-defined swelling was noted in relation to the right retromolar region (distal to 85) which was hard in consistency and nontender with buccal and mild lingual cortical expansion [Figure 2].{Figure 1}{Figure 2}

Baseline investigations were noncontributory. Radiographic examination with mandibular occlusal radiograph revealed multiple radiopacities enveloped by a radiolucent zone, surrounded by corticated border with buccal and mild lingual cortical expansion [Figure 3], and panoramic radiograph revealed a well-defined large area with multiple radiopacities enveloped by the radiolucent zone and surrounded by corticated border, extending from the distal aspect of the right primary second molar to the anterior border of the ramus of the mandible with the presence of an impacted right lower permanent first molar [Figure 4].{Figure 3}{Figure 4}

Based on the clinical and radiographical findings, a provisional diagnosis of complex odontome with a differential diagnosis of AFO, calcifying epithelial odontogenic tumor (CEOT), and calcifying odontogenic cyst (COC) was made. Excisional biopsy was done [Figure 5] and sent for histopathological examination which revealed connective tissue stroma that showed cell-rich ectomesenchymal component and odontogenic epithelium arranged in islands and strands. Irregularly arranged calcified component of minimal enamel matrix and dentinoid material was seen in the ectomesenchymal tissue. Odontogenic islands were lined by columunar or preameloblastic-like cells were noted, which was suggestive of ameloblastic fibro-odontoma [Figure 6].{Figure 5}{Figure 6}

 Discussion



The present case meets all the clinical, radiographical, and histopathological features for the diagnosis of AFO, which is a rare mixed odontogenic tumor. According to WHO classification of odontogenic tumors, it is placed under odontogenic epithelium with odontogenic ectomesenchyme, with or without hard tissue formation. AFO is a tumor similar to ameloblastic fibroma (AF) in terms of histological features, but with inductive changes that lead to the formation of dentin and enamel.[2] The term “ameloblastic fibro-odontoma” represents a histological combination of AF and complex odontoma.[4] Cahn and Blum (1952) postulated that histologically AF least differentiated tumor initially and develops later into a moderately differentiated form, AFO, and finally into complex odontoma.[2] The majority of mixed odontogenic tumors are hamartomatous and are considered as a part of developing complex odontoma line. Complex odontoma begins with AF or ameloblastic fibrodentinoma, and further these tumors develop into the second stage called AFO and finally convert into completely mineralized complex odontoma.[1] AFO is relatively rare, with frequency of occurrence about 1%–3%.[5] Most of the lesions are usually diagnosed during the first and second decades of life without any gender predilection and occur equally in both maxilla and mandible at the posterior region.[3],[4],[5],[6] The mean age of the patients as reported by Hooker is 11.5 years.[6] The present case is in accordance with the literature. Two most common complaints reported by the affected individuals are asymptomatic swelling and failure of tooth eruption, which are usually diagnosed incidentally on radiographic examination.[4] Occasionally, the tumor exhibits marked swelling, which results in facial disfigurement,[7] as in the present case.

Radiographically, the lesion usually appears as a well-defined radiolucent area containing various amounts of radiopaque material of irregular size and form.[1],[4],[6] Most cases are associated with an unerupted tooth located in the periphery, and often it is noted that the associated tooth is displaced in an apical direction, indicating the lesion is arising above the tooth.[1] Our case presented with radiographic features in accordance with the literature.

The other lesions showing mixed radiolucent and radiopaque features such as CEOT, immature complex odontoma, COC, and adenomatoid odontogenic tumor should be differentiated with AFO. Microscopically, it is composed of strands, cords, and islands of odontogenic epithelium embedded in a cell-rich primitive ectomesenchyme, resembling dental papilla. Dentin and enamel matrix is also seen; whether or not the tissues actually resemble “teeth” is irrelevant.[8]

As the lesion is nonaggressive and well-encapsulated, the recommended treatment is generally enucleation and there is little tendency for local invasion. The recurrence rate is very low; it happens when conservative treatment, with an attempt to save associated teeth, is performed.[1],[9] Malignant transformation rate is rare, but Howell and Burkes reported two cases of AFO that showed malignant transformation to ameloblastic fibrosarcoma.[10] The present case was treated with conservative surgery with enucleation. After a follow-up of 8 months, no recurrence was observed.

 Conclusion



The purpose of reporting this case is to enlighten the clinical and radiographic features of AFO, as it overlaps with other lesions such as complex odontoma, CEOT, and COC. This rare lesion remains a diagnostic dilemma for the oral physicians.

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

Nil.

Conflicts of interest

There are no conflicts of interest.

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