|Year : 2014 | Volume
| Issue : 1 | Page : 66-69
Ameloblastic fibrodentinoma of mandible
Nagendra Bhavani Sangala, Manay Munishekar, A Krishna, Sanjeevareddygari Shylaja
Department of Oral and Maxillofacial Pathology, SVS Institute of Dental Sciences, Mahabubnagar, Andhra Pradesh, India
|Date of Web Publication||10-Mar-2014|
Nagendra Bhavani Sangala
Department of Oral and Maxillofacial Pathology, S.V.S. Dental College, Mahabubnagar, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Odontogenic tumors are heterogeneous group of lesions with diverse histopathological and clinical features. Ameloblastic fibro-dentinoma (AFD) is rare mixed odontogenic tumor composed of odontogenic epithelium, immature connective tissue and are characterized by the formation of dysplastic dentin. Here, we present one such a rare case of AFD occurring in a 5-year-old female patient.
Keywords: Ameloblastic fibro-dentinoma, ameloblastic fibroma, ameloblastic fibro-odontoma, dentinoma, odontogenic tumors
|How to cite this article:|
Sangala NB, Munishekar M, Krishna A, Shylaja S. Ameloblastic fibrodentinoma of mandible. J NTR Univ Health Sci 2014;3:66-9
| Introduction|| |
According to Reichart et al. Ameloblastic fibrodentinoma (AFD) was first described by Straith (1936) under the term dentinoma.  Subsequently, it was called as immature dentinoma, ameloblastic fibroma (AF) with dentinoid formation and as fibro-ameloblastic type of dentinoma by different authors.  Most of the studies showed that AFD occurred in two forms mature and immature dentinoma. ,
AFD is slow growing, often asymptomatic lesion with a predilection for males. Radiologically, it shows unilocular or multilocular radiolucency with or without radio-opaque areas. Histologically, it is similar to AF but also shows dentin formation. Here, we present a rare case report occurring in a 5-year-old female patient.
| Case Report|| |
A 5-year-old female patient's father complained of swelling on the right side of the lower jaw since 6 months. Extraoral examination revealed gross facial asymmetry with a diffuse swelling extending anteroposteriorly from 2 cm behind the angle of mandible on the right side, anteriorly crossed the midline and extended to about 1 cm onto the left side. On palpation, it was bony hard [Figure 1]. Intraorally, the swelling was ill-defined extending from 81 to mesial portion of 85 with the obliteration of buccal vestibule. The overlying mucosa showed mild inflammation [Figure 2]. Orthopantamograph revealed a well-defined unilocular radiolucency extending from 72 to 85 [Figure 3]. Occlusal radiograph revealed expansion of buccal cortical plate with few radiopaque areas in a well-defined radiolucent lesion [Figure 4].
|Figure 2: Intraorally, ill-defined swelling was extending from 81 to 85 with obliteration of buccal vestibule|
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|Figure 3: Orthopantamograph revealed a well defined unilocular radiolucency extending from 72 to 85|
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|Figure 4: Occlusal radiograph revealed expansion of buccal cortical plate with few radiopaque areas in a well-defined radiolucent lesion|
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Based upon the incisional biopsy report given by a local pathological laboratory as ameloblastic fibro-odontoma (AFO), surgical excision was performed and multiple bits of soft and hard tissue specimen were sent to Department of Oral Pathology for histopathological diagnosis. The larger bit was measuring about
8 cm × 3.5 cm in size and was cream to gray in color with irregular surface. Hard tissue specimen included both deciduous teeth and permanent tooth buds. Multiple tissue bits were taken for processing [Figure 5]. Histopathological examination of H and E stained tissue sections revealed both odontogenic epithelial and ectomesenchymal components. Epithelial component was seen to be arranged in the form of strands and islands with peripheral tall columnar cells showing hyperchromatic nuclei and reverse polarity resembling ameloblasts and central cells resembling stellate reticulum. The background stroma was cellular with numerous plump fibroblasts resembling dental papilla or ectomesenchyme. Focal areas in the stroma showed homogenous eosinophilic areas resembling dentinoid surrounding the epithelial islands. At focal areas, this dentinoid also showed entrapped epithelial and ectomesenchymal cells [Figure 6]. Based on the above mentioned histopathological findings a diagnosis of AFD was arrived.
|Figure 5: Excisional biopsy specimen showing multiple bits of hard and soft-tissue specimen|
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|Figure 6: Strands and islands of odontogenic epithelium in a cell-rich ectomesenchyme along with deposition of dentin or osteodentin (H and E,×4)|
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| Discussion|| |
Odontogenic tumors are a heterogeneous group of lesions with diverse histopathologic features and clinical manifestations. Recent review on 1088 central odontogenic tumors states that the relative frequency of AF and AFO together constitutes 1.7%, which indicates the rarity of the lesion AFD.  Most of the studies showed that AFD occurred in two forms: mature and immature dentinoma. Immature form is thought to be an AF in which induction of mesenchymal cells by odontogenic epithelium has resulted in the formation of organic matrix of dentin or osteodentin and in mature type all the elements are similar, but with scanty or absence of and odontogenic epithelium. , According to Takeda, immature dentinoma is different from AFD as both epithelial and fibrous elements may resemble those of odontogenic fibroma rather than that of AF with or without dentin formation. 
Revision of 1992 edition of the WHO histological typing of odontogenic tumors suggested that the AF and AFD occur in two variants one being a neoplastic lesion which if left in situ does not differentiate further and the other variant is a hamartomatous lesion which is capable of developing into AFO and then differentiate into complex odontoma.  This continuum concept is not fully accepted as a significant number of residual or recurrent cases show no evidence of further maturation into more differentiated odontogenic lesions like AFO or odontoma. Studies shows AF do occur in ages well beyond the completion of odontogenesis and AFO can occur at very young age. ,
A review by Peter R. Morgan gives an idea that AFD is slow growing asymptomatic lesion occurring more commonly within or adjacent to the follicle of an unerupted tooth, especially in a lower third molar, in its path of eruption.  When the lesion involves the deciduous teeth, it more commonly occurs in the anterior jaw. It shows a predilection for first and second decade of life and also shows a male predominance.  It frequently occur as an intraosseous lesion.  Radiographic findings range from unilocular or multilocular radiolucency with or without radioopaque flecks. Histopathologically AFD is composed of strands and islands of odontogenic epithelium in a cell rich primitive ectomesenchyme resembling the dental papilla along with deposition of dentin or osteodentin, frequently preceded by zones of hyalinization.  Ulmansky et al. reported the presence of ghost cells in a tubular dentin of AFD.  Histologically, AFD/immature dentinoma should be differentiated from AFO, odontogenic fibroma and AF. In AFO, the epithelial components are arranged in the form of strands or islands with peripheral layer of cuboidal or columnar cells and central stellate reticulum-like tissue resembling the enamel organ. Connective tissue component is much more cellular resembling the dental papilla which shows an inductive change to form both enamel and dentin-like matrix, but in AFD, induction of only dentin can be appreciated. As previously mentioned, according to Takeda presence of dentin or osteodentin helps to differentiate AFD/immature dentinoma from AF and odontogenic fibroma respectively.  AFD has a good prognosis with surgical excision being the treatment of choice as it shows no or little recurrence.
| Conclusion|| |
Here, we present a rare case of AFD occurring in the mandible. More information on AFD has to be collected in order to better understand the lesion, its biological behavior and risk of malignant transformation. As there is a chance of malignant transformation, a proper follow-up should be maintained in order to rule out any evidence of recurrence or malignant transformation.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]