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Oral Diseases Apr 2018Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant... (Review)
Review
Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.
Topics: Ameloblastoma; Humans; Jaw Neoplasms; Neoplasm Recurrence, Local
PubMed: 28142213
DOI: 10.1111/odi.12646 -
The Surgeon : Journal of the Royal... Aug 2021Ameloblastomas are benign but locally invasive neoplasms which may grow to massive proportions and cause significant morbidity. Although some types of ameloblastoma can... (Review)
Review
Ameloblastomas are benign but locally invasive neoplasms which may grow to massive proportions and cause significant morbidity. Although some types of ameloblastoma can be treated predictably with aggressive surgical treatment, recurrent ameloblastoma and metastasising ameloblastoma are still difficult to treat. Recent studies have identified recurrent somatic and activating mutations in the mitogen-activated protein kinase (MAPK) and sonic hedgehog (SHH) signalling pathways in ameloblastoma. This development provided a possibility that molecular targeted therapies can be used as neoadjuvant treatment. In this review, we provide a summary of the latest WHO classification of ameloblastoma, the current understanding of genetic mutations and novel molecular targeted therapies arising from the recent developments.
Topics: Ameloblastoma; Hedgehog Proteins; Humans; Mitogen-Activated Protein Kinases; Molecular Targeted Therapy; Mutation
PubMed: 32712102
DOI: 10.1016/j.surge.2020.06.009 -
Oral Diseases Mar 2018Ameloblastoma are the most common odontogenic tumor. As they usually do not form metastasis, they are considered as benign tumors with a locally invasive growth pattern...
Ameloblastoma are the most common odontogenic tumor. As they usually do not form metastasis, they are considered as benign tumors with a locally invasive growth pattern and destruction of the jaws and the surrounding tissue (Oral Diseases, 23, 2017, 199). This article focuses on clinical, radiological, and therapeutic findings, which may influence diagnosis and treatment of ameloblastoma in the future.
Topics: Ameloblastoma; Humans; Jaw Neoplasms; Molecular Targeted Therapy
PubMed: 29480593
DOI: 10.1111/odi.12702 -
JNMA; Journal of the Nepal Medical... Jul 2022Ameloblastomas of jaws are benign odontogenic tumors of epithelial origin with four clinical variants: solid multicystic type, unicystic type, desmoplastic type, and...
UNLABELLED
Ameloblastomas of jaws are benign odontogenic tumors of epithelial origin with four clinical variants: solid multicystic type, unicystic type, desmoplastic type, and extraosseous type. The incidence rate of ameloblastoma is 0.92 per million person-years. Unicystic ameloblastoma refers to those cystic lesions that show clinical and radiologic characteristics of an odontogenic cyst but shows a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor proliferation on histological examination. Here is a unique case of unicystic ameloblastoma involving the mandible in a 70-year-old patient. The case was managed by segmental mandibulectomy and flap repair. Unicystic ameloblastoma accounts for only 13% of all known cases in scientific literature. Considering the rarity of the lesion, the purpose of presenting this report on a clinical case is to emphasize the importance of radiological evaluation and histopathological examination for the diagnosis of ameloblastoma.
KEYWORDS
ameloblastoma; odontogenic cysts; odontogenic tumors; segmental mandibulectomy.
Topics: Humans; Aged; Ameloblastoma; Mandible; Odontogenic Tumors; Odontogenic Cysts; Jaw
PubMed: 36705195
DOI: 10.31729/jnma.7566 -
Clinical & Translational Oncology :... Nov 2011Ameloblastoma is known as a benign, slow-growing, rare, odontogenic neoplasm. The solid/multicystic, the unicystic with a fibrous connective-tissue capsule and the... (Review)
Review
Ameloblastoma is known as a benign, slow-growing, rare, odontogenic neoplasm. The solid/multicystic, the unicystic with a fibrous connective-tissue capsule and the peripheral ameloblastoma represent the three well distinguished clinical types of ameloblastoma. Surgical resection with an attempt to achieve adequate free margins constitutes a well documented and accepted treatment modality. Controversies exist, however, with regard to the extent of operative intervention. Patients with inadequate or positive surgical margins or unresectable lesions can be treated with radiation or combined radiation and chemotherapy. The authors present a review of this sparse disease focusing on the special role and efficacy of radiation therapy in its management.
Topics: Ameloblastoma; Humans; Jaw Neoplasms
PubMed: 22082643
DOI: 10.1007/s12094-011-0735-5 -
American Journal of Clinical Oncology Dec 2007The purpose of this article is to review the pertinent literature and discuss the optimal treatment and outcomes for patients with ameloblastoma. Ameloblastoma is an... (Review)
Review
The purpose of this article is to review the pertinent literature and discuss the optimal treatment and outcomes for patients with ameloblastoma. Ameloblastoma is an uncommon benign, locally aggressive odontogenic neoplasm that usually occurs in the vicinity of the mandibular molars or ramus. Uncontrolled, ameloblastoma may cause significant morbidity and occasionally death. The median age is approximately 35 years and males and females are equally affected. The majority of ameloblastomas are multicystic, which are more difficult to eradicate than the unicystic and peripheral varieties. Although surgery is the mainstay of treatment, the extent of resection is controversial. Radical resections, including marginal and segmental mandibulectomy, result in local control rates exceeding 90%. In contrast, conservative procedures such as enucleation and/or curettage result in local control rates of approximately 80% and 50% for unicystic and multicystic ameloblastomas, respectively. Limited experience with radiotherapy indicates that it may reduce the risk of progression and result in long-term local control in the occasional patient with incompletely resectable disease. The optimal treatment for ameloblastoma is wide en bloc resection. Radiotherapy may improve the likelihood of local control in the occasional patient with incompletely resectable tumor.
Topics: Adult; Ameloblastoma; Female; Humans; Jaw Neoplasms; Male; Treatment Outcome
PubMed: 18091060
DOI: 10.1097/COC.0b013e3181573e59 -
Journal of Oral Pathology & Medicine :... May 2024Ameloblastoma (AM) is a benign, although aggressive, epithelial odontogenic tumour originating from tooth-forming tissues or remnants. Its aetiopathogenesis remains... (Review)
Review
Ameloblastoma (AM) is a benign, although aggressive, epithelial odontogenic tumour originating from tooth-forming tissues or remnants. Its aetiopathogenesis remains unclear; however, molecular analysis techniques have allowed researchers to progress in understanding its genetic basis. The high frequency of BRAF p.V600E as a main driver mutation in AM is well established; nevertheless, it is insufficient to explain its tumourigenesis. In this review, we aimed to integrate the current knowledge about the biology of AM and to describe the main genetic alterations reported, focusing on the findings of large-scale sequencing and gene expression profiling techniques. Current evidence shows that besides BRAF mutation and activation of the MAPK pathway, alterations in Hedgehog and Wnt/β-catenin pathway-related genes are also involved in AM pathogenesis. Recently, a tumour suppressor gene, KMT2D, has been reported as mutated by different research groups. The biological impact of these mutations in the pathogenesis of AM has yet to be elucidated. Further studies are needed to clarify the impact of these findings in the identification of novel biomarkers that could be useful for diagnosing, classifying, and molecular targeting this neoplasm.
Topics: Ameloblastoma; Humans; Mutation; Proto-Oncogene Proteins B-raf; Jaw Neoplasms; Wnt Signaling Pathway; Hedgehog Proteins; Gene Expression Profiling
PubMed: 38664938
DOI: 10.1111/jop.13538 -
The Annals of Otology, Rhinology, and... Dec 2003Ameloblastoma is a benign but locally aggressive neoplasm of the odontogenic epithelium, the treatment of which is controversial. A review was made of 22 patients...
Ameloblastoma is a benign but locally aggressive neoplasm of the odontogenic epithelium, the treatment of which is controversial. A review was made of 22 patients treated for histologically diagnosed ameloblastoma between January 1975 and January 2000. We recorded data relating to patient sex, age, site of involvement, histologic type, surgical treatment, and number of recurrences. All ameloblastomas were located in the mandible. The most common histologic patterns were follicular and plexiform lesions. A total of 22.7% of the tumors were unicystic ameloblastomas. Unicystic lesions were seen to affect younger patients than the rest of the histologic types. Eighteen patients were initially treated in our center, and 4 cases were referred to our center for secondary treatment. The number of recurrences was significantly lower in patients initially treated in our center. Primary treatment comprised enucleation and bone curettage in 10 cases and radical surgery in 7. Forty percent of the unicystic lesions and 53.3% of the non-unicystic ameloblastomas of our study presented at least 1 recurrence. Ameloblastoma is a polymorphic neoplasm for which the treatment is conditioned by a number of clinical and histologic factors. An individualized preoperative study is essential for treatment.
Topics: Adult; Aged; Ameloblastoma; Female; Humans; Male; Mandibular Neoplasms; Middle Aged; Neoplasm Recurrence, Local
PubMed: 14703106
DOI: 10.1177/000348940311201207 -
Head and Neck Pathology Jun 2019Ameloblastomas are benign but aggressive odontogenic tumors that most commonly affect the posterior mandible. Approximately 15% occur in the maxilla, with a subset...
Ameloblastomas are benign but aggressive odontogenic tumors that most commonly affect the posterior mandible. Approximately 15% occur in the maxilla, with a subset thought to originate from the epithelial lining of the sinonasal cavities. Histologically, sinonasal ameloblastomas are identical to those of the oral cavity, with classical features of palisaded columnar basilar cells surrounding a central proliferation that resembles the stellate reticulum of a developing tooth. Unlike the gnathic variant, sinonasal ameloblastomas tend to affect males more than females, and the incidence of diagnosis peaks at a later age, approximately 60 years old. The overall prognosis is favorable, with local recurrence being the most common long-term sequalae.
Topics: Adult; Ameloblastoma; Humans; Male; Maxillary Sinus Neoplasms
PubMed: 29846904
DOI: 10.1007/s12105-018-0933-3 -
Sultan Qaboos University Medical Journal Aug 2022This article aimed to collectively present the demographic, clinical, radiographic and histopathological features as well as the treatment performed along with its... (Review)
Review
This article aimed to collectively present the demographic, clinical, radiographic and histopathological features as well as the treatment performed along with its outcome for all the cases of adenoid ameloblastoma with dentinoid (AAD) reported in scientific literature till date. Ameloblastoma and adenomatoid odontogenic tumours are the most common odontogenic neoplasms. However, AAD, a hybrid variant of the two lesions, is found to be extremely rare. The lesion comprises of characteristic histopathological features of ameloblastoma and adenomatoid odontogenic tumour and shares certain clinical characteristics with either of the entities. AAD may be considered to be present at the more aggressive end of spectrum of benign odontogenic neoplasms. Owing to the frequent tendency of the lesions to be underdiagnosed, careful histopathological screening of submitted biopsies is warranted. With the increase in number of reported cases in the recent years, it is likely to be included as a separate entity in the upcoming World Health Organization classification.
Topics: Adenoids; Ameloblastoma; Biopsy; Humans; Odontogenic Tumors
PubMed: 36072074
DOI: 10.18295/squmj.9.2021.127