• Imaging Science in Dentistry
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• v.36 no.2
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• pp.117-121
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• 2006

Peripheral ameloblastoma is an extremely rare odontogenic soft tissue tumor with histologic characteristics similar to those of the intraosseous ameloblastoma. It appears in the gingiva and oral mucosa. And it usually does not show any bone involvement on radiographs, except for saucer shaped erosion of underlying alveolar bone. Recurrence is considered uncommon. We report a case of peripheral ameloblastoma with bone involvement. Histologically it presented with follicles and nest of tumor cells with palisading pattern. And radiographs showed the typical saucer shaped alveolar bone erosion at the distal area of right mandibular third molar. At 6-month follow-up after operation, no local recurrence was noted.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.3
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• pp.161-165
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• 2024

Peripheral ameloblastoma (PA) is believed to be the rarest variant of ameloblastoma and only has been described in isolated case reports. PA is usually confined to the soft tissues surrounding the supporting tissues of the teeth. Although it manifests nonaggressive behavior and can be treated with complete removal by local surgical excision, long term follow up is mandatory to prevent future recurrence and possible malignant transformation.

• Imaging Science in Dentistry
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• v.50 no.4
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• pp.373-376
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• 2020

This report presents a rare case of ameloblastoma with histopathologic and radiographic calcification, including 3-dimensional cone-beam computed tomographic (CBCT) images. A 22-year-old woman had hard swelling on the right mandible. Panoramic and CBCT images showed multilocular radiolucencies with internal calcification foci in the right mandible. Three-dimensional images clearly showed varying-sized radiopacities within the lesion from various angles. A histopathologic examination showed central squamous differentiation and more densely packed peripheral palisading ameloblastic cells. Many areas of keratin pearls and calcifications were also seen. Four previous reports have described 5 cases of ameloblastoma showing histopathologic calcification. This might be the first report to present the calcification of ameloblastoma on panoramic and CBCT images, especially on 3-dimensional images.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.316-321
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• 2005

Ameloblastoma is the most common odontogenic tumor of the jawbones, but the origin of this tumor has been remained to be unproven. Cytokeratins (CKs) are specific intermediate filament of epithelial cells, and vimentin is expressed in mesenchymal cells. The immunohistochemical detection of different CKs and vimentin has made it easier to know the origin of tumor. Paraffin-embedded tissue sections from 15 ameloblastomas and 1 ameloblastic carcinoma were used for immunohistochemical evaluation of CK 7, 8, 13, 14, 19 and vimentin. Their expression is evaluated in different tumor cells, which are observed in different type of tumors. In the follicular and reticular subtype, central stellate cells of tumor nests expressed CK 8, 14, 19 and peripheral columnar cells expressed CK 14. CK 7, and 13 were not expressed. Vimentin was detected in fibrous stroma around tumor nest, not in tumor cells. The tumor cells of ameloblastic carcinoma expressed CK 7, 14 and 19, but CK 8 was more weakly stained than that in ameloblastoma. Central stellate cells and peripheral columnar cells of acanthomatous subtype showed same expression pattern with others. Meta plastic squamous cells expressed CK 8, 14, 19 and keratinizing squamous cells expressed CK 13, 19. CK 7 and vimentin were not detected in tumor cells and vimentin was expressed in fibrous stroma. Most of the tumor cells of ameloblastoma showed CK 14 and CK 19 and did not express CK 7 and vimentin. These findings were similar to the immunophenotype of dental lamina. And these results will be beneficial to differential diagnosis of odontogenic tumors and other kind of tumors arising at the oral cavity.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.435-439
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• 2011

Ameloblastoma is an aggressive benign odontogenic epithelial tumour that may arise from the enamel organ, remnants of dental lamina, or the lining of an odontogenic cyst. It is usually categorized into solid or multicystic, unicystic, and peripheral types. Treatment ofameloblastomas include conservative methods such as marsupialisation, enucleation, and curettage; and radical treatments such as marginal or segmental resection. Radical treatments have resulted in lower recurrence rates; however, may also encounter esthetic, functional, and reconstructive problems. Unicystic ameloblastoma has been considered less aggressive and a lower recurrence tendency. Thus, many authors have recommended conservative treatment in cases of unicystic ameloblastoma. An 11 year-old boy presented with displaced second and third molars by luminal unicystic ameloblastoma in the mandible. Cyst enucleation, curettage, and third molar extraction were done. No signs of recurrence or esthetic problems such as facial asymmetry were seen radiologically and clinically, up to 8 years 2 months postoperatively.

• Toxicological Research
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• v.33 no.2
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• pp.141-147
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• 2017

Peripheral ameloblastic odontoma is a rare variant of odontogenic tumor occurring in the extraosseous region. The present report describes a spontaneous tumor in male Sprague-Dawley (SD) rats. The clinically confirmed nodule in the right mandibular region was first observed when the rat was 42 weeks and remained until the terminal sacrifice date when the animal was 48 weeks of age. At necropsy, a well demarcated nodule, approximately $2.5{\times}2.0{\times}2.0cm$, protruded from the ventral area of the right mandible. The nodule was not attached to mandibular bone and was not continuous with the normal teeth. Histopathologically, the tumor was characterized by the simultaneous occurrence of an ameloblastomatous component and composite odontoma-like elements within the same tumor. The epithelial portion formed islands or cords resembling the follicle or plexiform pattern typical of ameloblastoma and was surrounded by mesenchymal tissue. Formation of eosinophilic and basophilic hard tissue matrix (dentin and enamel) resembling odontoma was observed in the center of the tumor. Mitotic figures were rare, and areas of cystic degeneration were present. Immunohistochemically, the epithelial component was positive for cytokeratin AE1/AE3 (CK AE1/AE3), and the mesenchymal component and odontoblast-like cells were positive for vimentin, in the same manner as in normal teeth. On the basis of these findings, the tumor was diagnosed as a peripheral ameloblastic odontoma in an extraosseous mandibular region in a SD rat. In the present study, we report the uncommon spontaneous peripheral ameloblastic odontoma in the SD rat. We also discuss here the morphological characteristics, origin, histochemical, and immunohistochemical features for the diagnosis of this tumor.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.674-679
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• 1996

The peripheral odontogenic fibroma (WHO type) is a relatively rare and characteristically benign and unencapsulated, exophytic gingival mass of fibrous connective. Odontogenic epithelium is found within the gingival mass, but usually appears to playa minor role when compared to the fibrous component. The connective tissue is ranged from markedly cellular to relatively acellular and well collagenized. but the connective tissue in this case report appears less cellular. Peripheral odontogenic fibroma must be differentiated histologically from peripheral ossifying fibroma, Peripheral cemental epithelial odontogenic tumor and Peripheral ameloblastoma. The author reports the following conclusions after clinical and radiological examination, excisional biopsy and reviewing literatures. 1. Peripheral odontogenic fibroma is rare lesion and frequently occurs in interdental papila as a form of fibroblastic connective tissue including odontogenic epithelium within the lesion. 2. Peripheral odontogenic fibroma must be differentially diagnosed with Peripheral ossifying fibroma by including less cellular connective tissue, odontogenic epithelium and dysplastic dentin 3. Treatment consists of surgical excision including removal of alveolar bone which is eroded under the lesion

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.619-623
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• 2016

Ameloblastoma is the most common epithelial odontogenic tumor. It may show locally invasive behavior resulting in recurrence and malignancy. Therefore, appropriate diagnosis of this tumor is necessary. The aim of this study was to evaluate clinicopathological characteristics of ameloblastomas in an Iranian population. We present a 40-year retrospective study of patients diagnosed from 1971 to 2010 in the Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mashhad, Iran. Information gathered from patient records included age, gender, tumor location and histologic type. The frequency of odontogenic tumors among all lesions was 2.08% and ameloblastoma with 88 samples demonstrated the greatest prevalence (41.5%). Regarding gender, 60% of samples occurred in males. The mean age of studied patients was $33.02{\pm} 15.74years$ with a peak of occurrence in the third decade of life. The most frequent location of tumor was the mandibles (93.2%). Eighty five (96.6%) tumors were recorded as benign and 3 (3.4%) as malignant. Of benign tumors, 62 (72.9%), 20 (23.5%) and 3 (3.6%) cases were of conventional, unicyctic and peripheral types, respectively. In contrast to most previous studies, the most common histologic subtype in the present study was plexiform. Knowledge of the incidence of ameloblastoma and its clinicopathologic features including most common location, gender and age distribution in different ethnogeographic backgrounds is necessary for accurate diagnosis and proper treatment.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.1-10
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• 2000

Purpose : 1. Retrospectively evaluate the accuracy of tentative diagnosis or impression from the clinico-radio-graphic materials of jaw lesions which showed mixed lesions associated with teeth. 2. To observe the diagnostic importance of the calcified part of the lesions which appear as radiopaque areas. Materials and Methods: 14 cases of jaw lesions which showed mixed lesions associated with teeth were reviewed. These lesions were mostly diagnosed as adenomatoid odontogenic tumors (6 cases) or calcifying odontogenic cysts with (4 cases) or without odontomas (4 cases). The calcified elements of the lesions which demonstrated various sizes and patterns of radiopaque shadows resembled odontoid tissues in some cases but could not be defined in some other cases radiographically. Results : The final histopathologic diagnosis confirmed adenomatoid odontogenic tumors in 4 of the 6 cases. The remaining 2 cases turned out to be odontoma and ameloblastic fibroodontoma. The 4 cases of calcifying odontogenic cysts with odontomas were correct in 3 cases but remaining 1 case was just odontoma. The 4 cases of calcifying odontogenic cysts were proved to be odontogenic keratocyst, calcified peripheral fibroma, unicystic ameloblastoma and squamous cell carcinoma. Conclusion : The diagnostic accuracy of the adenomatoid odontogenic tumors and calcifying odontogenic cysts were high when the lesions show typical appearance. The calcifications which show radiopaque areas could be odontomas or dystrophic calficifations or remnants of bone fragments from resorption.