Journal of Indian Academy of Oral Medicine and Radiology

: 2016  |  Volume : 28  |  Issue : 3  |  Page : 310--313

An odontogenic tumor mimicking a dentigerous cyst in a 13-year-old female: A rare clinical presentation

Leelavathy Jegadeesan1, Winnifred Christy Ambrose1, Srivel Vigneshwari Ammamuthu2, Sabarinath Thirukonda Ragunath3,  
1 Department of Oral Medicine and Radiology, Church of South India College of Dental Sciences and Research, Madurai, India
2 Department of Oral and Maxillofacial Surgery, Church of South India College of Dental Sciences and Research, Madurai, India
3 Department of Oral and Maxillofacial Pathology, Church of South India College of Dental Sciences and Research, Madurai, India

Correspondence Address:
Dr. Leelavathy Jegadeesan
21, 5th street, Park Town, P and T Nagar, Madurai - 625 017


Ameloblastic fibroma is a relatively rare benign odontogenic tumor in which both the epithelial and ectomesenchymal components are neoplastic. A 14-year-old girl presented with a complaint of unerupted maxillary right premolar. The panoramic radiograph revealed a well-circumscribed unilocular radiolucency involving an unerupted maxillary right first premolar. The lesion was enucleated and the material was sent for histopathologic examination. This case emphasized the importance of careful differential diagnosis of intraosseous oral lesions and reported a rare lesion as well as its atypical location.

How to cite this article:
Jegadeesan L, Ambrose WC, Ammamuthu SV, Ragunath ST. An odontogenic tumor mimicking a dentigerous cyst in a 13-year-old female: A rare clinical presentation.J Indian Acad Oral Med Radiol 2016;28:310-313

How to cite this URL:
Jegadeesan L, Ambrose WC, Ammamuthu SV, Ragunath ST. An odontogenic tumor mimicking a dentigerous cyst in a 13-year-old female: A rare clinical presentation. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2022 Dec 3 ];28:310-313
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Full Text


Ameloblastic fibroma (AF) is a benign odontogenic tumor considered to be a true mixed tumor composed of neoplastic epithelium and mesenchymal tissues.[1],[2],[3],[4],[5],[6] This tumor is rare, representing only 2% of all odontogenic tumors.[1],[5],[6] AF is a tumor of childhood and adolescence which occurs exclusively in the first and second decades of life usually seen in the ages of 7 to 51 years. In the majority of cases, the lesion is usually evident in the mandible, slow-growing and painless, with or without tooth eruption.[6],[7],[8],[9] However, the tooth impaction and delayed eruption may be associated with dental developmental defects or abnormalities such as amelogenesis imperfecta. Whereas in few other cases, the tumors are asymptomatic and diagnosed only during routine oral/radiographic examination.[9]

AF consists of odontogenic ectomesenchyme, resembling the dental papilla, and epithelium, resembling dental lamina and enamel organ without dental hard tissues.[7] Knowledge of the malignant potential in the mesenchymal spindle cells of AF should aid in determining the management of these benign tumors to prevent malignant transformation to ameloblastic fibrosarcoma.[3],[7] The most appropriate treatment method for AF is still uncertain, although several authors have suggested conservative approach. However, tumors may recur following surgical removal and progress to malignancy. Thus, long-term follow-up of AF is recommended.[8] This report describes an interesting case of AF that affected the maxillary region of a young girl, which was associated with an unerupted maxillary right premolar.

 Case Report

A 14-year-old girl reported with a complaint of an extraoral swelling associated with unerupted permanent maxillary right premolar since 1 year. General examination revealed a healthy child. The medical, surgical, family, and social histories were unremarkable. Extraorally, a diffuse swelling of size 1 × 1 cm in diameter was evident along the right nasolabial fold region, which was firm in consistency, nontender, and fixed [Figure 1]. Intraoral examination revealed a small painless expansion of the maxillary buccal cortical plate associated with missing first premolar where the overlying mucosa was intact and the color and consistency was normal [Figure 2].{Figure 1}{Figure 2}

Maxillary occlusal radiograph revealed a unilocular radiolucency surrounded by a well-defined radiopaque border within which there was an impacted premolar [Figure 3]. Orthopantomogram (OPG) revealed a well-defined unilocular radiolucent lesion in the right maxillary region. The crown of the permanent first premolar was apparent within the lesion. A dense radiopaque mass with prominent external margins surrounded by thin radiolucent zone was evident above the crown of the unerupted tooth, which was suggestive of odontoma [Figure 4]. The second premolar was present. Computed tomography (CT) scanning confirmed the findings of the panoramic radiograph [Figure 5]. Based on the clinical and roentgenographic findings, a presumptive provisional diagnosis of dentigerous cyst was made. Differential diagnosis included expanded follicular space, adenomatoid odontogenic tumor, and AF.{Figure 3}{Figure 4}{Figure 5}

Under local anesthesia, the lesion was completely excised through an intraoral approach, thereby protecting the definitive second premolar. The enucleated material was sent for histological examination [Figure 6]. Microscopically, the lesion consisted of tumor tissue composed of cell-rich mesenchymal tissue, resembling dental papilla. The lesion also revealed numerous proliferating odontogenic islands, which were arranged in the form of narrow cords or discrete, small islands. The histopathological diagnosis confirmed the diagnosis to be AF [Figure 7].{Figure 6}{Figure 7}


AF are neoplasms of odontogenic epithelium and mesenchymal tissues and are categorized as mixed odontogenic tumors. Other mixed odontogenic lesions, such as ameloblastic fibro-odontomas and odontomas share some of the clinical, radiographic and histologic similarities with AF.[1],[4] Earlier it was suggested that these lesions represent a spectrum of a single entity, with AF being the least differentiated of the tumors, maturing and developing into ameloblastic fibro-odontomas and later odontomas.[4],[9] Along with tumor associated demographics, this theory has been repudiated.

The least differentiated lesion, AF, usually occurs, on average, in an older age group rather than the more differentiated ameloblastic fibro-odontoma and odontoma.[1],[2],[3],[7] Furthermore, ameloblastic fibro-odontomas and odontomas are better categorized as hamartomas, and as a result, unlike AF, they have minimal chances of recurrence or malignant transformation.[10] Therefore, despite many similarities, it is essential to differentiate AF from other mixed odontogenic lesions because it has true neoplastic qualities.[11] Radiographically, AFs are unilocular lesions, occasionally multilocular when larger, with smooth well-demarcated borders. Cortical expansion may or may not be discernable on plane film. Because these lesions are frequently associated with unerupted teeth, initially they may be interpreted as dentigerous cysts.[2],[8]

Grossly, AF appears as firm, lobular soft tissue mass with a smooth surface. If the lesion is associated with a tooth, it may accompany the specimen. A capsule is generally not appreciated. Microscopically, an AF is composed of a connective tissue background that appears to recapitulate dental papilla, resembling stellate reticulum. This tissue is composed of spindle and angular cells with little collagen, imparting a myxomatous appearance. The epithelial component is made up of thin branching cords or small nests of odontogenic epithelium with little cytoplasm and basophilic nuclei. Larger nests may show a central area of stellate reticulum.[5],[11],[12] Mitoses should not be a feature of AF. The presence of mitosis should expand the differential diagnosis to include malignant entities and ameloblastic fibrosarcoma.[5],[9] Finally, immunohistochemistry generally does not aid in differentiating AF from other mixed odontogenic tumors. Surgical excision or thorough curettage with removal of the affected teeth is the treatment of choice. The recurrence rate varies among sources, but is considered to be low. The possibility of malignant transformation of AF into ameloblastic fibrosarcoma is well-documented, but still uncommon.


In the case reported here, the focal point was the failure of eruption of a maxillary first premolar. This disturbance may or may not be associated with a pathology such as AF. Thus, this case emphasizes the importance of careful differential diagnosis in dentistry, while reporting a rare lesion and its atypical location.

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.

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Conflicts of interest

There are no conflicts of interest.


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