• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.303-308
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• 1994

The ameloblastoma is considered to be a slowly growing locally invasive tumor with a high rate of recurrence if not removed adequately. Ameloblastoma generally dose not metastasize to distant places. In very rar case, ameloblastoma changed its histologic appearance to carcinoma or showed distant metastasie, these generally called malignant ameloblastoma. Inadequate surgical procedures, radiation therapy, and a long duration of this tumor seem to have significant relation to the development of metastasis. Therefore, adequate surgical treatment of the primary lesion plays an important role in the prevention of metastasis postoperatively. This report described an instance of malignant ameloblastoma and review of literature.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.226-230
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• 2002

Carcinomas derived from ameloblastomas have been designated by a variety of terms, including malignant ameloblastoma, ameloblastic carcinoma, metastatic ameloblastoma, and primary intra-alveolar epidermoid carcinoma. The term of ameloblastic carcinoma is differentiated from the term of malignant amelblastoma and is defined as an ameloblastoma in which there is histologic evidence of malignancy in the primary tumor or the recurrent tumor(or metastasis), regardless of whether it has metastasized. The well-documented and adequately followed cases are currently lacking and this report described an instance of ameloblastic carcinoma with good result after treatment and review of literature.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.298-300
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• 2003

Ameloblastomas are generally considered to be benign tumors of odontogenic epithelial origin with high local recurrence. Rarely ameloblastomas exhibit malignant behavior with development of metastases. In this report, we present a 19-year-old woman with ameloblastoma in the right ascending ramus and multiple recurrences. Eleven years after first therapy, ameloblastoma metastasized to ipsilateral submandibular lymph node. We also review literature about cause, treatment and work-up of malignant ameloblastoma.

• Imaging Science in Dentistry
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• v.50 no.4
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• pp.359-363
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• 2020

Ameloblastic carcinoma is a rare odontogenic malignant tumor with the histologic features of both ameloblastoma and carcinoma. It occurs more frequently in the mandible than in the maxilla and it may appear de novo or develop from a preexisting ameloblastoma or odontogenic cyst. Rapidly progressing, painful swelling is the most common symptom, and radiographically, it shows significant bone resorption and cortical perforation. This report described a case of ameloblastic carcinoma in a 45-year-old man who presented with swelling in the left mandible. The lesion showed combined features of benign findings, such as an expansile cortex with a distinct border, and malignant findings, such as a large exophytic mass with frank bone resorption. Excisional biopsy was performed and a final diagnosis of ameloblastic carcinoma was made.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.195-201
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• 2021

Unusual radiographic findings of intraosseous ameloblastoma have been reported and discussed. In the case discussed herein, cone-beam computed tomography (CBCT) clearly showed many radiographic features that were ambiguous on conventional radiographs, including an ill-defined periphery, extensive superficial buccal extension with minimal lingual extension, obvious bucco-crestal expansion, and multiple triangular (Codman's triangle-like) areas of periosteal reaction. Based on the above-mentioned findings, the differential diagnosis was a long-term infected benign or low-grade malignant lesion. An incisional biopsy was performed, and the histopathologic diagnosis was acanthomatous ameloblastoma. Recurrence of the lesion was clearly detected on CBCT images at 4 and 8 years after surgery. These unusual radiographic findings have never been reported to be associated with ameloblastoma, and thus may contribute to novel concepts in radiographic interpretation in the future. This report also underscores the important role played by CBCT as a comprehensive diagnostic tool and for definite confirmation of recurrence.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3327-3330
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• 2014

Background: The purpose of the study was to analyse the clinicopathological spectrum of benign and malignant odontogenic tumours (OT) in Pakistan. Materials and Methods: This retrospective study was carried out at the Armed Forces Institute of Pathology (AFIP) Rawalpindi. Seven years archival records of histologically diagnosed odontogenic tumours, both benign and malignant, were collected and the lesions re-diagnosed histologically in accordance with the WHO classification of head and neck tumours (2005). Clinical as well as histological data were analysed and frequency of each type of OT was calculated using computer software programme SPSS (version 17). Mean tumour size was calculated and Chi-square test was applied to find associations of age, gender and site with each histological type of tumour. Results: Only 1.7% of the odontogenic tumours diagnosed in this said period were malignant while the remaining 98.3% were benign. Amongst benign lesions, ameloblastoma was the most common (61.3%) type while primary intraosseous squamous cell carcinoma (1.7%) was the only reported malignant tumour. Mean age of the affected patients was $31.7{\pm}16.7$ years with posterior mandible as the commonest site involved. Conclusions: Our study revealed ameloblastoma and primary intraosseous squamous cell carcinoma as the commonest diagnosed benign and malignant tumours respectively. There was a significant difference in age and site of origin of different types of OT at the time of their presentation. However, all the tumours showed male predominance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.453-459
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• 2010

Introduction: Ameloblastic carcinoma is a rare malignant lesion, and may arise from either carcinoma ex-ameloblastoma or de novo carcinoma. Aberrant promoter hypermethylation of the tumor-associated genes leading to their inactivation is a common event in many cancer types. The p16/CDKN2/INK4A gene and p16 5 protein are involved directly in regulating the cell cycles. Cadherins are cell adhesion molecules that modulate the epithelial phenotype and regulate tumor invasion. The aim of this study was to evaluate the roles of p16 and E-cadherin methylation and loss of p16 and E-cadherin expression in the malignant transformation of an ameloblastoma. Materials and Methods: Eight cases of ameloblastoma, including 4 benign ameloblastomas without recurrence, 2 benign ameloblastomas with recurrence and 2 carcinoma ex-ameloblastomas, were examined. The promoter hypermethylation profile of the p16 and E-cadherin genes was studied using methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining for p16 and E-cadherin expression. Results: 1) Aberrant CpG island methylation of the p16 gene was detected in 3 of the 4 benign ameloblastomas without recurrence and 1 of the 2 benign ameloblastomas with recurrence. 2) Aberrant CpG island methylation of the E-cadherin gene was found in 1 of the 4 benign ameloblastomas without recurrence. 3) A loss of p16 expression was noted in 1 of 4 benign ameloblastomas without recurrence and 1 of 2 carcinoma ex-ameloblastomas. 4) A loss of E-cadherin expression was noted in 2 of the 4 benign ameloblastomas without recurrence, 1 of the 2 benign ameloblastomas with recurrence and 2 of the 2 carcinoma ex-ameloblastomas. 5) A loss of p16 expression was observed in 1 of the 4 cases showing aberrant methylation of the p16 gene. 6) A loss of E-cadherin expression was observed in 3 benign ameloblastoma case showing aberrant methylation of the E-cadherin gene. Conclusion: These results suggest that loss of E-cadherin expression related to the other genetic pathway (not methylation) might be an adjuvant indicator predicting the malignant transformation of an ameloblastoma. However, the number of samples in this study was too small and the relationship between the treatment methods and clinical course were not defined. Therefore, further study will be needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.199-205
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• 2003

The p53 protein was discovered in 1979 as cellular 53-kD nuclear phosphoprotein bound to the large transforming antigen of SV40 virus. $P21^{WAF1/CIP1}$, which has been described as the critical downstream mediator of p53, is known to suppress DNA replication and arrest the G1 cell cycle by quaternary complex with cyclin D, cyclin-dependent kinase(CDK) and proliferating cell nuclear antigen(PCNA). In these days, some studies shows that the p21 can be induced by independent pathways. There are various reports about the expression of p21 (67%.82.4%) in oral squamous cell carcinoma. But these studies are mostly done in malignant tumor not in benign tumor. So we decided to study the expression of p21 in ameloblastoma and the relationship between p53 and p21 as a downstream mediator of p53 in ameloblastoma. We investigated the expression of p21 and p53 with the method of immunohistochemistry. We selected 30 cases of ameloblastoma tissue blocks (acanthomatous type: 5 cases, follicular type: 8 cases, plexiform type: 17 cases) imbedded in paraffin. We used 30 cases of normal gingival tissues and 30 cases of squamous cell carcinoma tissues (SCC) respectively and compared their results with those of ameloblastoma. We made slides with the streptavidin-biotin methods and used monoclonal antibody DO-7 (Novocastra, Newcastle, United Kingdom) as p53 antibody and monoclonal antibody M7202 (DAKO, California, U.S.A.) as p21 antibody. We used Pearson's correlation coefficient to analyse the relationship. The results were as follows: 1. p21 was expressed in ameloblastoma about 30% and this is lower than that of normal gingiva and SCC. 2. In normal gingiva and ameloblastoma, p21 expression was correlated with p53 expression. 3. In SCC, p21 were expressed about 83.3% and this is more than that of p53. But there was no correlation between p21 and p53 expression. We confirmed p21 expression and relation with p53 in ameloblastoma. But, to confirm the function of p21, more studies about p21 expression in malignant ameloblastoma and ameloblastic carcinoma are needed.

• Korean Journal of Head & Neck Oncology
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• v.31 no.2
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• pp.49-53
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• 2015

Ameloblastoma is the most common benign odontogenic tumor, with approximately 80% arising in the mandible and the remainder in the maxilla. However, the infratemporal fossa is a rare site in which ameloblastomas occur. Although malignant transformations or metastasizing processes are extremely rare, tumor recurrence is common, if the tumor is not completely resected. Because reoperation could deteriorate quality of life in the patients and increase surgical morbidity, radical surgery is often recommended to minimize recurrence rates. In this report, we presented our experience of resection of ameloblastoma in the left infratemporal fossa with sufficient safe margin through a lower cheek flap approach and marginal mandibulectomy.

• The Korean Journal of Cytopathology
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• v.4 no.2
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• pp.166-170
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• 1993

We describe the cytologic features of metastatic ameloblastoma which presented as multiple bilateral lung nodules. The patient was a 22-year-old male who had recurrent ameloblastoma of the mandible 7 years after the diagnosis of primary lesion. Fine needle aspiration of one of the pulmonary nodules revealed patchy arrangement of cell clusters with outer palisading columnar cells and inner irregular loose polygonal cells. Most of tumor cells had plenty cytoplasm and ovoid nuclei which lacked either pleomorphism or hyperchromatism. The cytologic findings corresponded with histologic features of the primary site which was also benign looking ameloblastoma.