Ameloblastic fibro-odontoma AFO predominantly occurs in the jaw bones of children and young adults. Extraosseous AFO is extremely rare. We describe a peripheral ameloblastic fibro-odontoma in the maxillary gingiva of a 3-year-old girl. The clinical appearance resembled fiery red reactive gingival lesions.

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Ameloblastic fibrodentinoma is a benign odontogenic tumor belonging to the category of "odontogenic epithelium with odontogenic ectomesenchyme" along with recognition of induction in the form of dentin in atypical or dysplastic forms.

The biological behaviour of ameloblastic fibrodentinoma is not very different from ameloblastic fibroma; hence, it is treated similarly by conservative procedures. It is important to understand the histopathogenesis of these rare tumors. Though rare, they are an independent entity awaiting recognition.

Here, we report a case of amelobalstic fibrodentinoma in a year-old female patient. Odontogenic tumors are a diverse set of tumors. The recent World Health Organization WHO classification on odontogenic tumors categorizes odontogenic tumors as epithelial, mesenchymal, and mixed [ 1 ]. Classically, mixed and mesenchymal odontogenic tumors show evidence of odontogenic induction.

AFD is a benign odontogenic tumor that histomorphologically simulates an ameloblastic fibroma AF but can form dysplastic dentin. It predominantly presents as an intraosseous tumor in the gnathic skeleton, more common in the mandible than the maxilla.

Though peripheral lesions are reported, they form miniscule numbers. It accounts for a small percentage of odontogenic tumors and only around 64 cases have been reported so far since its first description by Straith in [ 2 - 3 ]. Here, we present a case of ameloblastic fibrodentinoma in a year-old girl with features of ameloblastic fibroma and induction in the form of different types of dysplastic dentin adding a 65th case report to the literature.

A year-old female child reported to the clinical department with a complaint of non-erupted posterior teeth. There was no associated pain or paraesthesia. Medical history and family history were noncontributory. On examination, a swelling 3 x 2. The teeth 46 and 47 were missing, whereas 45 and 44 were erupted with normal morphology and were well aligned.

An orthopantomogram taken revealed a well-defined unilocular radiolucent lesion in relation to 44 to 48 region. The radiolucency extended from 44 to the retromolar area displacing and impacting 46, 47 and distally displacing developing 48 into the ramus of the mandible.

The mandibular right second premolar showed no resorption or displacement but was placed completely in the tumor mass. The displaced 43 was also evident. A provisional diagnosis of benign odontogenic tumor was made and an incisional biopsy was done. The epithelial strands consisted of cuboidal to columnar cells with hyperchromatic nuclei. At few areas the epithelial strands were opening into small follicles with peripheral tall columnar cells and central stellate reticulum-like cells.

The follicles at few areas showed basal cell hyperplasia. Few mitotic figures were noted. A diagnosis of ameloblastic fibrodentinoma was made. A conservative surgical excision was carried out as the treatment for the lesion. The tumor was soft and friable; hence, it was removed in multiple bits. The tumor could be easily separated from the bony walls. Histopathology of the excisional mass was similar to that of the incisional biopsy.

The tumor showed the presence of a capsular structure that was incomplete. Multiple layers of collagen were seen as a capsule along with neurovascular bundles at certain areas. The tumor revealed odontogenic strands in the primitive myxoid ectomesenchymal stroma resembling an ameloblastic fibroma.

Some new findings added enigma to the histopathological findings. The tumor showed certain areas that were similar to odontogenic apparatus in the bell stage, with large enamel organ like structures. Adjacent to the ameloblast-like cells, dysplastic dentin was laid, dentin with predentin-like areas were seen.

Induction of dentin was seen in many areas and in many forms. There was no evidence of enamel or enamel matrix formation even after extensive sectioning, ruling out the diagnosis of AFO. The other differentials considered were ameloblastoma. Though, few odontogenic follicles with peripheral columnar cells and central stellate reticulum like cells were evident, highly cellular ectomesenchyme was also present impressing that the tumor showed proliferation of both epithelial and mesenchymal components, whereas ameloblastoma shows proliferation of only epithelial component and even the conventional reversal of polarity of the ameloblast-like cells was also not seen, thus ruling out ameloblastoma [ 3 ].

AFD is a rare neoplasm of odontogenic epithelium with immature ectomesenchyme and formation of dysplastic dentin. For a while it had also been named as a dentinoma [ 3 - 4 ]. Controversy surrounds the categorization of AFDs. The continuum concept with AF, AFO, and odontomas proposed by Cahn and Blum remains disproved on the basis of age of occurrence, site of occurrence, histopathology, gender, and evidence studied in recurrent cases [ 2 - 5 ].

However, cases have been reported where AFDs show enhanced growth enlarging to considerable sizes causing cortical plate perforation. There have been reports where recurrence and malignant transformation have been noticed, which show the tumor to have significant growth potential and thus be a true neoplasm [ 2 , 4 - 5 ]. We propose AFDs to be recognized as an independent tumor entity and acknowledge its rarity. Generally, a slow growing asymptomatic tumor, in some instances is associated with unerupted teeth and is commonly seen before the age of 20 years with a male predilection, the ratio being It has been observed that AFD in relation to permanent teeth are commonly seen in the posterior region, whereas those in relation to deciduous teeth are seen in the anterior region [ 2 , 5 ].

Radiologically, AFD are well delineated radiolucencies with varying degrees of radiopacity and frequently found in relation to malposed, unerupted teeth [ 6 ]. The present case though was seen in a year-old female patient, presented in the mandibular right posterior quadrant involving unerupted 46, 47, and 48 as a unilocular, well-defined radiolucency of approximately 3 x 2 cm, but no such opacity nor cortical perforation was seen.

The alveolar ridge superiorly was completely destroyed allowing the tumor to present as a soft tissue mass extending on the alveolar ridge in the region of 43 to The histopathology of AFD has great resemblance to AF, showing odontogenic epithelium in strands and small islands resembling dental lamina and enamel organ placed in a very cellular primitive ectomesenchyme resembling the dental papillae [ 4 ].

Few odontogenic epithelial islands or follicles were lined by tall cuboidal to columnar cells with central stellate reticulum-like cells similar to ameloblastic follicles. Cystic degeneration in the follicles could also be seen [ 5 ].

Dentin deposition in relation to the odontogenic epithelium and ectomesenchyme was seen in the form of osteodentin, dentinoid or tubular dentin. Dentin was also seen to entrap the odontogenic epithelium and ectomesenchymal cells. Some areas of hyalinization which may or may not be dentin were also evident [ 9 ]. It is important to note that no enamel or enamel matrix was seen in cases of AFD [ 3 ].

Small follicles or islands with central stellate reticulum-like cells with few follicles undergoing cystic degeneration were also evident. The ectomesenchyme in which the odontogenic epithelium was arranged was very cellular with plump fibroblasts. Multiple areas showed a halo-like hyalinization around the odontogenic epithelial follicles impressing upon induction, though not bearing resemblance to odontogenic hard tissue.

Few areas showed enamel organ in early bell stage like differentiation with no evidence of enamel formation. Different forms of dentin such as osteodentin, dentinoid, and dentin undergoing globular mineralization were noted to be formed in the ectomesenchyme and also in relation to odontogenic epithelium at few areas. Osteodentin-like areas showed matrix with ectomesenchymal cells entrapped in the matrix. At certain places, osteodentin-like areas were bordered by odontogenic epithelium.

Large areas with globular mineralization along with unmineralized predentin-like area were seen. Many areas showed non-tubular dentin entrapping cells in multiple lacunae in close relation to odontogenic epithelium resembling dentinoid as reported by Gardner and Farquhar [ 10 ]. Most of the inductive material in the form of dysplastic dentin with globular mineralization, osteodentin, and dentinoid were seen close to the periphery whereas a halo lining of hyalinization around many odontogenic epithelial follicles was also a common finding in many areas, as reported by Girish and Garg [ 9 ].

No enamel-like material was found in the present case, so ameloblastic fibro-odontome was not considered. However, hyalinization needs to be categorized as non-dentinal or non-specific induction in the ecto-mesenchyme, the significance of which is not very clear or specific and might be an abortive effect too.

More work needs to be done in detailing and recognition of inductive changes in odontogenic tissues and tumors. The present case clearly shows a clinical presentation that depicts a destructive tumor. The histopathology showcases a varied amount and variety of dysplastic dentin, validating true odontogenic induction in the tumor.

Hence, we think that this case might add value to understand it as a true independent entity among odontogenic tumors. We would like to thank the staff and postgraduate students of the Department of Oral and Maxillofacial Pathology, Krishnadevaraya College of Dental Sciences for their constant support and help.

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Do not disregard or avoid professional medical advice due to content published within Cureus. The authors have declared that no competing interests exist. Consent was obtained by all participants in this study. National Center for Biotechnology Information , U. Journal List Cureus v. Published online Jun Author information Article notes Copyright and License information Disclaimer.

Corresponding author. Reshma Venugopal moc. Received May 8; Accepted Jun This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract Ameloblastic fibrodentinoma is a benign odontogenic tumor belonging to the category of "odontogenic epithelium with odontogenic ectomesenchyme" along with recognition of induction in the form of dentin in atypical or dysplastic forms. Keywords: dysplastic dentin, dentinoid, mandibular tumor, paediatric odontogenic tumors, induction, benign odontogenic tumors, ameloblastic fibrodentinoma. Introduction Odontogenic tumors are a diverse set of tumors.

Case presentation A year-old female child reported to the clinical department with a complaint of non-erupted posterior teeth. Open in a separate window. Figure 1. Mild erythematous swelling with the indentation marks of the opposing maxillary teeth is seen on the right posterior alveolar ridge of mandible Arrow.


Ameloblastic Fibrodentinoma: A Case with Varied Patterns of Dysplastic Dentin

Ameloblastic fibroma and related lesions constitute a group of lesions, which range in biologic behaviour from true neoplasms to hamartomas. This group of lesions is also sometimes referred to as mixed odontogenic tumors and usually includes ameloblastic fibroma, ameloblastic fibrodentinoma and ameloblastic fibro-odontoma. Despite numerous efforts however, there is still considerable confusion concerning the nature and interrelationship of these mixed odontogenic tumors and related lesions. The malignant counterpart of these lesions namely aameloblastic fibrosarcoma, ameloblastic dentinosarcoma and ameloblastic odontosarcoma respectively are said to arise secondarily in their benign counterpart or de novo. Recurrence of the benign lesion raises the risk towards malignant transformation therefore a radical surgery should be planned inspite of enucleation or curettage.


Aggressive atypical ameloblastic fibrodentinoma: Report of a case

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. This article has been cited by 1 Ameloblastic fibrodentinoma and ameloblastic fibro-odontoma: an updated systematic review of cases reported in the literature Bruno Ramos Chrcanovic,Ricardo Santiago Gomez Journal of Oral and Maxillofacial Surgery. Users Online: Ameloblastic fibrodentinoma of mandible.

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