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Turk Patoloji Dergisi 2022The 5th edition of the World Health Organization (WHO) Classification of Head and Neck Tumors opened to online access in March 2022. This edition is conceptually similar... (Review)
Review
The 5th edition of the World Health Organization (WHO) Classification of Head and Neck Tumors opened to online access in March 2022. This edition is conceptually similar to the previous classification of odontogenic lesions. The only newly defined entity in odontogenic lesions is adenoid ameloblastoma, which is classified under benign epithelial odontogenic tumors. While not odontogenic, the surgical ciliated cyst is a new entry to the cyst classification of the jaws. In other respects, a very important change was made in the new blue books that added 'essential and desirable diagnostic criteria' for each entity to highlight the features considered indispensable for diagnosis. In this article, we review the odontogenic tumors and cysts of the jaw sections of the Odontogenic and Maxillofacial Bone Tumors Chapter, outlining changes from the 2017 WHO classification and summarizing the essential diagnostic criteria and new developments.
Topics: Ameloblastoma; Head and Neck Neoplasms; Humans; Odontogenic Cysts; Odontogenic Tumors; World Health Organization
PubMed: 35578902
DOI: 10.5146/tjpath.2022.01573 -
Cureus Aug 2022Ameloblastoma is one of the most common benign odontogenic tumors of the jaw that constitutes about 10% of all tumors that arise in the mandible and maxilla. It is a... (Review)
Review
Ameloblastoma is one of the most common benign odontogenic tumors of the jaw that constitutes about 10% of all tumors that arise in the mandible and maxilla. It is a slow-growing but locally invasive tumor that presents with painless swelling of the mandible or maxilla. The World Health Organization (WHO) classification of 2017 describes ameloblastomas of the following four types: ameloblastoma; unicystic ameloblastoma; extraosseous/peripheral ameloblastoma; and metastasizing ameloblastoma. The diagnosis of ameloblastoma requires computerized tomography (CT) imaging as well as a biopsy. A biopsy is helpful in differentiating ameloblastoma from ossifying fibroma, osteomyelitis, giant cell tumor, cystic fibrous dysplasia, myeloma, and sarcoma. The best treatment of ameloblastoma is aggressive en bloc resection with simultaneous reconstruction. The high recurrence rate and large tissue defects have been long-standing issues in the treatment of ameloblastoma. Recent molecular developments strongly suggest the possibility of targeted therapy with better outcomes in ameloblastomas. We present a detailed updated narrative review of our current understanding and management of this enigmatic tumor.
PubMed: 36127985
DOI: 10.7759/cureus.27734 -
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 -
Journal of Pharmacy & Bioallied Sciences Apr 2015Ameloblastoma is a benign odontogenic tumor generally present in the jaw bone. The tumor originates from the residual epithelium of the tooth germ, epithelium of... (Review)
Review
Ameloblastoma is a benign odontogenic tumor generally present in the jaw bone. The tumor originates from the residual epithelium of the tooth germ, epithelium of odontogenic cysts stratified squamous epithelium and epithelium of the enamel organ. It represents approximately 1% of oral tumors. About 80% of ameloblastomas occur in the mandible mainly the third molar region and the remaining 20% in the upper jaw. Ameloblastoma clinically appears as an aggressive odontogenic tumor, often asymptomatic and slow-growing, with no evidence of swelling. This article deals with a complete review on ameloblastoma.
PubMed: 26015700
DOI: 10.4103/0975-7406.155891 -
The American Journal of Case Reports Jul 2015Ameloblastic carcinoma secondary type is an extremely rare and aggressive odontogenic neoplasm that exhibits histological features of malignancy in primary and...
BACKGROUND
Ameloblastic carcinoma secondary type is an extremely rare and aggressive odontogenic neoplasm that exhibits histological features of malignancy in primary and metastatic sites. It arises through carcinomatous de-differentiation of a pre-existing ameloblastoma or odontogenic cyst, typically following repeated treatments and recurrences of the benign precursor neoplasm. Identification of an ameloblastic carcinoma, secondary type presenting with histologic features of malignant transformation from an earlier untreated benign lesion remains a rarity. Herein, we report 1 such case.
CASE REPORT
A 66-year-old man was referred for management of a newly diagnosed ameloblastic carcinoma. He underwent radical surgical intervention comprising hemimandibulectomy, supraomohyoid neck dissection, and free-flap reconstruction. Final histologic analysis demonstrated features suggestive of carcinomatous de-differentiation for a consensus diagnosis of ameloblastic carcinoma, secondary type (de-differentiated) intraosseous.
CONCLUSIONS
Ameloblastic carcinoma, secondary type represents a rare and challenging histologic diagnosis. Radical surgical resection with adequate hard and soft tissue margins is essential for curative management of localized disease.
Topics: Aged; Ameloblastoma; Biopsy; Diagnosis, Differential; Humans; Lymphatic Metastasis; Male; Mandibular Neoplasms; Mandibular Osteotomy; Neck Dissection; Radiography, Panoramic
PubMed: 26126621
DOI: 10.12659/AJCR.893918 -
Pathologie (Heidelberg, Germany) Aug 2022Odontogenic tumors (OTs) are rare, with an estimated incidence rate of less than 0.5 cases per 100,000 per year. The causes of OTs remain unclear. Nonetheless, the... (Review)
Review
BACKGROUND
Odontogenic tumors (OTs) are rare, with an estimated incidence rate of less than 0.5 cases per 100,000 per year. The causes of OTs remain unclear. Nonetheless, the majority of OTs seem to arise de novo, without an apparent causative factor. Although the etiopathogenesis of most OTs remains unclear, there have been some recent advances in understanding the genetic basis relating to specific histologies and clinical features. Molecular analyses performed by different techniques, including Sanger sequencing, next-generation sequencing, and allele-specific PCR, have uncovered mutations in genes related to the oncogenic MAPK/ERK signaling pathway. Genetic mutations in these pathway genes have been reported in epithelial and mixed OTs, in addition to odontogenic carcinomas and sarcomas. Notably, B‑RAF proto-oncogene serine/threonine kinase (BRAF) and KRAS proto-oncogene GTPase (KRAS) pathogenic mutations have been reported in a high proportion of ameloblastoma and ameloblastoma-related tumors and adenomatoid odontogenic tumors, respectively.
OBJECTIVE
To discuss how molecular profiling aids in diagnostic classification of odontogenic tumors.
CONCLUSION
Molecular profiling of odontogenic tumors helps to identify patients for neoadjuvant therapies and reduces postoperative morbidity.
Topics: Humans; Ameloblastoma; Odontogenic Tumors; Pathology, Molecular; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras)
PubMed: 36378285
DOI: 10.1007/s00292-022-01152-7 -
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 -
Journal of Clinical and Experimental... Mar 2021Ameloblastoma is a locally aggressive tumor, originated from odontogenic epithelium, and affects the jawbones with an elevated recurrence rate. The molecular mechanisms... (Review)
Review
BACKGROUND
Ameloblastoma is a locally aggressive tumor, originated from odontogenic epithelium, and affects the jawbones with an elevated recurrence rate. The molecular mechanisms involved with the pathogenesis of this tumor remain undetermined. This review aimed to describe the current data regarding epigenetic alterations in ameloblastoma.
MATERIAL AND METHODS
A systematized electronic search was performed in the English-language literature in three databases, combining the following keywords: ameloblastoma, epigenetic, methylation, noncoding RNA, histone acetylation.
RESULTS
According to the gathered results of 11 studies in this review, epigenetic alterations could induce the development and progression of ameloblastoma. DNA methylation has been the most assessed mechanism in ameloblastomas.
CONCLUSIONS
Current literature data indicate that epigenetic events can be involved in the etiopathogenesis of ameloblastomas. Ameloblastoma, epigenetic, methylation, noncoding RNA, histone acetylation.
PubMed: 33680332
DOI: 10.4317/jced.56191 -
Sultan Qaboos University Medical Journal Aug 2023Papilliferous keratoameloblastoma (PKA) is a rare entity, and not much is known about its clinicodemographic features or biological nature. This review aimed to provide... (Review)
Review
Papilliferous keratoameloblastoma (PKA) is a rare entity, and not much is known about its clinicodemographic features or biological nature. This review aimed to provide clarity regarding the characterisation of the demographic, clinical, radiological and histopathological features of PKA. Case reports of PKA were identified through a systematic search across multiple databases. The search yielded a total of 10 cases, half of which were of Indian origin. All the cases invariably occurred in the mandibular posterior region and involved the right side; only one case primarily involved the left side of the mandible. PKA should be considered a variant of the conventional ameloblastoma that is towards the more aggressive end of the spectrum. It tends to occur in older individuals (in their fifth decade or older), with a marked propensity to occur in the right mandibular posterior region. Surgical resection with diligent follow-up is warranted in the treatment of PKA.
Topics: Humans; Aged; Ameloblastoma; Mandible; Thorax
PubMed: 37655071
DOI: 10.18295/squmj.5.2023.021