An updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study

Adenomatoid odontogenic tumor: A histopathologic profile of 43 cases with evidence supporting a mixed odontogenic origin

BACKGROUND

Adenomatoid Odontogenic Tumor (AOT) accounts for 3% of all odontogenic tumors. It has been classified by WHO as an odontogenic tumor of purely epithelial origin. The current study attempts to establish the origin of the tumor along with detailed histopathological and clinicoradiographic analysis of 43 cases of AOT.

MATERIAL AND METHODS

Forty-three cases were reviewed from the departmental archives for demographic data, radiographic features and histological features. Further, histopathological slides were stained with Picrosirius Red (PSR) and observed under polarised light.

RESULTS

A majority of the cases were seen in the anterior jaws (76.7%), and were less than 3 cms (76.7%) in greatest dimension. Equal number of cases were of follicular and extra-follicular location while one was peripheral. Predominantly solid histological pattern was noted in 53.5%. Varied sub-patterns were observed with most cases exhibiting solid nodules and strands of tumor cells. Few cases showed melanin pigmentation. Over a third of cases (37.2%) showed dentigerous cyst like areas and one case each showed features of ossifying fibroma and focal cemento-osseous dysplasia. Tumor droplets, hyaline rings within duct-like structures, dentinoid material and osteodentin showed reddish yellow birefringence when observed under polarised microscopy post PSR staining.

CONCLUSION

This study highlights the diverse histopathological variation of AOT with evidence to reclassify it as a mixed odontogenic tumor based on the polarising microscopic findings with PSR staining.

Pediatric Odontogenic Tumors

Odontogenic tumors are rare tumors of the jaws that arise from remnants of the tooth forming apparatus. Some odontogenic tumors demonstrate strong predilection for pediatric patients including the unicystic ameloblastoma, adenomatoid odontogenic tumor, ameloblastic fibroma, ameloblastic fibro-odontoma, odontoma, and primordial odontogenic tumor. In this review, we discuss the clinical, radiographic, histopathologic, and molecular characteristics of select odontogenic tumors that demonstrate pediatric predilection and review management.

Cystic Lesions of the Jaws: The Top 10 Differential Diagnoses to Ponder

BACKGROUND

Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that may be reactive or neoplastic in nature. While most cystic jaw lesions are benign, variability in biologic behavior makes distinction between these entities absolutely crucial.

METHODS

Review.

RESULTS

Two clinical cases are presented in parallel and are followed by an illustrated discussion of the ten most likely differential diagnoses that should be considered when confronted with a cystic jaw lesion. Strong emphasis is placed on the histologic differences between these entities, empowering readers to diagnose them with confidence. Perhaps even more importantly, the more common diagnostic pitfalls in gnathic pathology are discussed, recognizing that a definitive diagnosis cannot be rendered in every situation. The histologic diagnoses for the two clinical cases are finally revealed.

CONCLUSION

Cystic lesions of the maxilla and mandible may be odontogenic or non-odontogenic. The most common cystic lesions are the reactive periapical cyst, and the dentigerous cyst (which is developmental in nature). It is important to note that cystic neoplasms also occur in the jaws, and that the presence of inflammation may obscure the diagnostic histologic features of lesions like odontogenic keratocyst and unicystic ameloblastoma. Ancillary testing is of limited diagnostic value in most scenarios. However, both clinical and radiographic information (such as the location, size, duration, associated symptoms, and morphology of the lesion in its natural habitat) are significantly useful.

Dental implants at sites of focal high and mixed density osseous lesions: Clinical practice guidelines

FOCUSED CLINICAL QUESTION

Under what circumstances may a clinician consider dental implant placement at a site exhibiting a focal high or mixed density (HMD) osseous lesion radiologically?

SUMMARY

Some conditions and pathologic entities exhibiting high and mixed density radiological appearance pose low risk for dental implant failure or complications following implant surgery. However, other lesions represent contraindications to implant placement, and implant surgery at such sites can result in severe morbidity.

CONCLUSION

Potential implant sites exhibiting focal HMD osseous lesions/conditions present varying levels of risk. In most cases, optimal management will include advanced imaging of the site, multidisciplinary consultations, and detailed informed consent to assure full understanding of procedural risks, benefits, and complications. Currently, clinical recommendations rely on case reports, opinion, and usual practice (level 3 evidence). The strength of each recommendation provided in this report is categorized as level C.

Peripheral adenomatoid odontogenic tumor of mandible - A synchronous presentation or a subtype?!

Adenomatoid odontogenic tumor (AOT) with its unique and varied presentations histologically and clinically has always been an enigma. AOTs are multifaceted in their appearance with reports pointing out to its occurrence as a synchronous tumor, a purely cystic variant or with multiple foci; however, the three commonly encountered forms are Follicular/Coronal, Extra Follicular/Extra Coronal and Peripheral variants. Here, we present a subtype of the Peripheral AOT (PAOT) seen synchronous with an intraosseous cystic variant of AOT in a 16-year-old female in the anterior mandible. This case is unique in that a PAOT occurring adjacent to a focally aggressive intraosseous cystic AOT (not associated with impacted tooth) could either be synchronous with no connection to the intraosseous component or could actually be an erupted intraosseous cystic variant with peripheral manifestation. Features of cortical expansion, perforation and displacement of teeth without resorption were seen. Histologically, all the classical features of AOT along with abundant eosinophilic amorphous fibrinous deposits, cellular vacuolization, clearing of cells, dystrophic and reactive bone formation and a cystic lining were seen. Thus, this case of PAOT would add to the myriad presentation of AOT making it one of the most often discussed odontogenic tumor.

Odontogenic and Developmental Oral Lesions in Pediatric Patients

This article reviews odontogenic and developmental oral lesions encountered in the gnathic region of pediatric patients. The process of odontogenesis is discussed as it is essential to understanding the pathogenesis of odontogenic tumors. The clinical presentation, microscopic features, and prognosis are addressed for odontogenic lesions in the neonate (dental lamina cysts/gingival cysts of the newborn, congenital (granular cell) epulis of the newborn, melanotic neuroectodermal tumor, choristoma/heterotopia, cysts of foregut origin), lesions associated with unerupted/erupting teeth (hyperplastic dental follicle, eruption cyst, dentigerous cyst, odontogenic keratocyst/keratocystic odonogenic tumor, buccal bifurcation cyst/inflammatory collateral cyst) and pediatric odontogenic hamartomas and tumors (odontoma, ameloblastic fibroma, ameloblastoma, adenomatoid odontogenic tumor, primordial odontogenic tumor). Pediatric odontogenic and developmental oral lesions range from common to rare, but familiarity with these entities is essential due to the varying management implications of these diagnoses.

Adenomatoid odontogenic tumor mimicking a lateral periodontal cyst - A rare case report in the mandible

Adenomatoid odontogenic tumor (AOT) is benign tumor of the oral cavity characterized by its slow growth accounting to 3%-7% of the odontogenic tumors. AOTs mostly occur in the maxillary anterior region and most often than not associated with impacted anterior teeth. It affects the younger age group, especially below 20 years and is commonly seen in females. It occurs as two main variants - (a) central/intraosseous which is more common and (b) peripheral which is rare. The location of the lesion, its association with the impacted tooth, is the basis for the classification of AOT. The intraosseous type may be related to unerupted tooth (follicular variant) or may not be related to unerupted tooth (extra-follicular variant). Radiologically, AOT presents predominantly as a unilocular cystic lesion enclosing the unerupted tooth. The lesion presents rarely with a cystic component. Radiopacities on the intraoral periapical radiograph are seen as discrete foci having a flocculent pattern within radiolucency even with the presence of minimal calcified deposits. AOT being benign in nature is enucleated with least chances of recurrence. Here, we present a rare case of extra-follicular variant of adenomatoid odontogenic tumor in a 19-year-old female patient.

Extrafollicular Adenomatoid Odontogenic Tumor in the Maxillary Incisor Region Disguised as Gingival Swelling

Adenomatoid Odontogenic Tumor (AOT) is a benign, non-invasive tumor with slow but progressive growth, mainly affecting younger patients, predominantly females. It is more often located in maxilla, involving an unerupted or erupted tooth, mostly canine. There are three variants, namely follicular, extra-follicular and peripheral. Permanent cuspids account for 60% of all follicular and 89% of all extra-follicular AOT. This article discusses a unique case of extra-follicular AOT in 9 year old male patient associated with partially erupted maxillary central incisor.

Multiple adenomatoid odontogenic tumours associated with eight impacted teeth

Adenomatoid odontogenic tumour (AOT) is a benign tumour that arises from odontogenic epithelial remnants. AOTs usually present as innocuous lesions with limited growth potential. Multiple AOTs are frequently reported in the literature, with reports of tumours associated with up to seven impacted teeth. Multiple AOTs have also been described in association with Schimmelpenning syndrome. This case report highlights the rare occurrence of multiple AOTs involving eight impacted teeth in a 9-year-old male patient. Radiographic examination showed features of enamel hypoplasia and multiple prominent dilated gubernaculum dentis associated with some of the impacted teeth. The patient also presented with a linear epidermal nevus involving the left face and intraoral mucosal papillomatous growths, clinical features highly compatible with Schimmelpenning syndrome.

Clinical and demographic characteristics of adenomatoid odontogenic tumors: analysis of 116 new cases from a single center

Introduction

The adenomatoid odontogenic tumor is a relatively uncommon odontogenic neoplasm representing about 4.7% of all odontogenic tumors.

Objective

The aim of this study was to determine the demographic and clinical profile of the adenomatoid odontogenic tumors in a Sri Lankan population.

Methods

Data gathered from the cases received for a period of 38 years from the Department of Oral Pathology, Faculty of Dental Sciences, University of Peradeniya. Request forms, biopsy reports and electronic data base of the department were used to obtain relevant information. Demographic data including age, gender and location of the tumor were included in the analysis.

Results

Out of 116 cases of adenomatoid odontogenic tumor, the mean age was 21.02 ± 11.24. It occurs more fre quently in the second decade of life, more prevalent in females, most often associated with the maxilla, predominantly affecting anterior jaw bones and presenting mostly in the right side of the jaw bone. The results from the present study showed the statistically significant relationship with site of occurrence (maxilla/mandible) and age (p < 0.005). Further, depending on whether it occurs in anterior/mid/posterior site also showed a significant relationship with age (p ≤ 0.001). However, side of occurrence, left or right or site of occurrence, showed no statistically significance with age (p > 0.05).

Conclusion

Adenomatoid odontogenic tumor occurs more frequently in the second decade of life with a significant female predominance and the commonest site is anterior maxilla. This study revealed few differences on demographic and clinical presentations of adenomatoid odontogenic tumor from some regions of the world.

Peripheral Adenomatoid Odontogenic Tumor - A Rare Cause of Gingival Enlargement: A Case Report with CBCT Findings

Introduction

Adenomatoid odontogenic tumor (AOT) is an uncommon benign odontogenic lesion with varied clinical and histological presentation. It has slow growth potential and a low recurrence rate. The tumor is mainly seen in females in the second decade of life, predominantly affecting the maxilla and associated most often with unerupted canine teeth, earning the epithet “two-thirds tumor”. There are three variants: intrafollicular, extrafollicular, and peripheral. The peripheral or extra osseous type is a rare form that arises in gingival tissue.

Case Presentation

This article describes a case of AOT in a 10-year-old girl who presented with gingival enlargement in relation to the maxillary left central incisor. Interestingly, intraoral periapical radiography did not show any significant findings. However, cone-beam computed tomography of the site revealed significant bone loss in the area. A surgical excision was done. Histopathological examination revealed features of AOT. Based on clinical, radiographic, and histological evidence, a diagnosis of peripheral AOT (PAOT) was made.

Conclusion

PAOT is a rare disease entity in children that mimics gingival swelling, and may often be misdiagnosed by dentists. With literature still ambiguous on the origin of the tumor and biological course, it becomes imperative to examine any gingival swelling in children with a proper clinical examination, periapical radiography, and if necessary cone-beam computed tomography. Excision and histopathological evaluation will help in confirming the exact disease condition.

CEOT Variants or Entities: Time for a Rethink? A Case Series with Review of the Literature

The first detailed description of calcifying epithelial odontogenic tumor (CEOT) are ascribed to Jens Pindborg, but this tumor was described some years previously. Subsequently, CEOT was included in the 1971 WHO classification of odontogenic tumors and a since then number of variants have been described, which have added confusion to the diagnostic criteria. We aimed to survey the literature on the variants of CEOT, in parallel with a review of our single institution experience of CEOTs. Cases identified were collated, including available clinical, radiological and histological information and then reviewed, taking into account changes in the understanding and classifications of odontogenic tumors since initial diagnosis. We identified 26 cases from 1975 to 2017 for which histological material was available. Of these, only 13 (50%) showed the "classic" histological appearance, whilst two cases were identified as recognized variants. In 11 cases, other diagnoses or a differential diagnosis were preferred, with no agreed diagnosis in four of these. The proliferation fraction (Ki67) in the 10 cases tested was 2.1% ± 0.18. These findings illustrate the diagnostic challenges in this group of tumors and highlight the gaps in knowledge. Techniques, such as EWSR1 gene cytogenetic analysis, may be helpful in cases with clear cells. However, in other areas of controversy, including the non-calcifying and Langerhans cell rich variants, further investigation, perhaps utilizing sequencing technologies may be needed to refine the classification. Owing to the relative rarity of these lesions it would be beneficial if future work could be pursued as an international collaboration.

Adenomatoid Odontogenic Tumor Associated with Impacted Mandibular Canine - A Case Report

Adenomatoid odontogenic tumor (AOT) is a relatively rare, benign, hamartomatous, and cystic odontogenic neoplasm that was first described more than a century ago. It accounts for 2-7% of all odontogenic tumors. The lesion still continues to intrigue experts with its varied histomorphology and controversies regarding its development. The present article describes a case of cystic AOT with an unusual histomorphology associated with an impacted 43 in a 15-year-old male.

An international collaborative study of 105 new cases of adenomatoid odontogenic tumors

OBJECTIVE

The aim of this study was to report the clinicopathologic features of 105 new cases of adenomatoid odontogenic tumor (AOT) from Brazil, Guatemala, Mexico, and South Africa.

STUDY DESIGN

Clinical and radiographic data were collected from records of 5 oral pathology laboratories, and all cases were microscopically reviewed.

RESULTS

This series of cases included 36 (34.2%) from South Africa; 33 (31.4%) from Brazil; 23 (21.9%) from Mexico; and 13 (12.3%) from Guatemala. Seventy-two patients (68.5%) were females and 33 patients (31.4%) were males, with an average age of 19.2 years. The tumors predominantly affected the anterior maxilla (48.5%), followed by the anterior mandible (29.5%); posterior mandible (15.2%); and posterior maxilla (6.6%). Sixty-three tumors (63.6%) were follicular, 34 (34.3%) were extrafollicular, and 2 (2%) were peripheral. In most cases, the tumors caused considerable cortical expansion (average size 3.4 cm). Microscopically, most cases showed rosette-like and duct-like structures.

CONCLUSIONS

This is one of the largest case series of AOTs reported in the literature and the first multicenter study involving populations from Latin America and South Africa. In a fifth of the present cases, the posterior regions of the gnathic bones were affected and the tumors demonstrated larger sizes compared with cases occurring in other populations.

Clinico-Pathological Presentations of Cystic and Classic Adenomatoid Odontogenic Tumors

The objective of the study is to present the clinico-pathological features of cystic and classic adenomatoid odontogenic tumors (AOTs) in order to identify the differences between the two variants of AOT. Materials and method: The study sample comprised of 41 AOTs, which were categorized into cystic and classic AOTs. Cystic AOTs are diagnosed as such when macroscopic and microscopic evidence of a cyst is present together with histopathological criteria of AOT (WHO–2017). Results: The study sample comprised of eleven cystic and thirty classic AOTs. Eight cystic AOTs were regarded as arising from dentigerous cysts as these lesions were attached to the cemento-enamel junction of the impacted teeth. Though not statistically significant, in contrast to classic AOTs which showed female predilection, cystic AOTs were more prevalent in males. Cystic AOTs tend to present as significantly larger lesions compared to classic AOTs (p < 0.02). In both cystic and classic AOTs, duct-like structures and epithelial whorls were the two most prominent histopathological features present in the majority of tumors. Two AOTs with massive amounts of dentinoid occurred in the mandible and presented as large lesions that eroded cortical bone. None of the 12 patients with follow-up information presented with recurrences. Conclusion: Except for the size of the lesion, no significant clinico-pathological differences were observed between cystic and classic AOTs. Therefore the cystic AOTs can be considered as a variant of AOT with enucleation, simple excision, or radical excision as the treatment of choice depending on the extent of the lesion, similar to classic AOTs.

Adenomatoid odontogenic tumour: A rare threat to orthodontic treatment planning

This case report aims to increase awareness of how an adenomatoid odontogenic tumour (AOT) can present in a similar fashion to a dentigerous cyst and the importance of accurate histopathological diagnosis. In this case, the AOT resulted in loss of the upper left permanent canine in a patient who already had a congenitally absent upper left second premolar, compromising the original orthodontic treatment plan.

KRAS mutations drive adenomatoid odontogenic tumor and are independent of clinicopathological features

Adenomatoid odontogenic tumor is a benign encapsulated epithelial odontogenic tumor that shows an indolent clinical behavior. We have reported in a few adenomatoid odontogenic tumors mutations in KRAS, which is a proto-oncogene frequently mutated in cancer such as lung, pancreas, and colorectal adenocarcinomas. We aimed to assess KRAS mutations in the hotspot codons 12, 13, and 61 in a large cohort of adenomatoid odontogenic tumors and to test the association of these mutations with clinical (age, site, tumor size, follicular/extrafollicular subtypes) and histopathological parameters. Thirty eight central cases were studied. KRAS codon 12 mutations were assessed by TaqMan allele-specific qPCR (p.G12V/R) and/or Sanger sequencing, and codon 13 and 61 mutations were screened by Sanger. Histological tumor capsule thickness was evaluated by morphometric analysis. Additionally, the phosphorylated form of the MAPK downstream effector ERK1/2 was investigated. Statistical analysis was carried out to test the association of KRAS mutations with clinicopathological parameters. KRAS c.35 G >T mutation, leading to p.G12V, was detected in 15 cases. A novel mutation in adenomatoid odontogenic tumor, c.34 G >C, leading to p.G12R, was detected in 12 cases and the other 11 were wild-type. Codon 12 mutations were not associated with the clinicopathological parameters tested. RAS mutations are known to activate the MAPK pathway, and we show that adenomatoid odontogenic tumors express phosphorylated ERK1/2. In conclusion, a high proportion of adenomatoid odontogenic tumors (27/38, 71%) have KRAS codon 12 mutations, which occur independently of the clinicopathological features evaluated. Collectively, these findings indicate that KRAS mutations and MAPK pathway activation are the common features of this tumor and some cancer types. Although it is unclear why different codon 12 alleles occur in different disease contexts and the complex interactions between tumor genotype and phenotype need clarification, on the basis of our results the presence of KRAS p.G12V/R favors the adenomatoid odontogenic tumor diagnosis in challenging oral neoplasm cases.

Peripheral adenomatoid odontogenic tumor in a cloak of an epulis: report of a rare case

Background

Adenomatoid odontogenic tumor constitutes an uncommon benign odontogenic tumor which is well-known as “two-thirds tumor” (two-thirds of adenomatoid tumors occur in the maxilla, two-thirds occur in young females, two-thirds of the cases are associated with un-erupted teeth and two-thirds of the affected teeth are canines). Larger part of these present as intra - osseous tumors while peripheral counterparts are extremely rare. Peripheral adenomatoid odontogenic tumor is a unique entity which generally presents as a slow growing gingival swelling with minimal bone involvement. This often leads to its erroneous diagnosis as a simple gingival lesion and the real diagnosis is only revealed after its microscopic evaluation. It exhibits a marked predilection for maxillary gingiva of incisor region and most commonly affects the younger females.

Case presentation

We report a case of 25 years old female patient of African ethnicity who presented with a 2 × 2 cm mass attached to the left mandibular gingiva in cuspid- bicuspid region which is an unusual site for AOT. It was accompanied by slight bone loss. With the differential diagnosis of gingival epulis and peripheral ossifying fibroma; surgical excision was performed. The light microscopic examination of the specimen aided the final diagnosis of Adenomatoid odontogenic tumor with the histopathological features identical to its intra osseous counterpart.

Conclusion

In this case, the tumor is present on the mandibular gingiva in a 25 years old patient which is an atypical location and age for this tumor; also, the only individual case reported in an African patient. Only, a meager number of peripheral adenomatoid odontogenic tumor cases have been logged so far with majority of them occurring in maxillary gingiva. Furthermore, an ambiguity still prevails regarding its true origin and possible biological course. Hence, reporting of similar cases should be encouraged to facilitate the better understanding of its varied epidemiological details and clinical presentation.

The World Health Organization classification of odontogenic and maxillofacial bone tumors: An appraisal

Classification is the process of grouping similar entities under one category for the ease of their comprehension and better handling. Medical classification dates back to the days of William Farr who is credited with the development of a nosology, which later served as the forerunner for the modern-day disease classification by ICD. The WHO system of classification is a time-honoured system that has prevailed from decades together and is under constant evolution. The classification of odontogenic tumours was first formulated by Pierre Paul Broca and has undergone several transformations over years. Though the earlier classifications and their modifications by several authors and even by the WHO appeared to be fitting for their time, the latest edition of WHO classification of odontogenic and maxillofacial bone tumours neither seems to be complete nor perfect, even at the present context. It is unfortunate that even with the advancement of molecular biology, the present WHO classification on Odontogenic and Maxillofacial bone tumours, fails to serve as a 'reference standard' in the true sense of the term. This article highlights the limitations of the current classification with constructive criticism that may help in further improvement.

Surgical Management of Extrafollicular Variant of Adenomatoid Odontogenic Tumor in the Maxillary Posterior Region

Background

Adenomatoid odontogenic tumor (AOT) is a relatively uncommon benign neoplasm of odontogenic epithelial origin, accounting for less than 5% of odontogenic tumors.

Case Report

The reported case describes morphological characteristics, clinical course, radiographic and histopathological features, and surgical therapy of an extrafollicular variant of AOT in the maxillary posterior region. An asymptomatic swelling on the left side in the posterior region of the maxilla, gradually increased since approximately 12 months, developed in a 16-year-old Caucasian female patient. Radiographic images revealed a well-defined, unilocular radiolucency, with some small foci of radiopacity inside, and root resorption of the first and second molars. On the base of the histological examination of the specimen retrieved by incisional biopsy, the diagnosis of AOT was made, and the conservative surgical enucleation of the lesion was performed.

Discussion

The present case was reported in agreement with an extensive review, in which it was recommended to discontinue reporting classic follicular cases because their clinicopathological profile was well-known, but to continue reporting well-documented cases of the extrafollicular variant, with indication of the exact position.

Conclusion

The present case was reported in order to expand the knowledge about the clinical behavior and surgical treatment of the extrafollicular variant of AOT.

Adenomatoid odontogenic tumor: An updated analysis of the cases reported in the literature

PURPOSE

To review the clinical and radiographic features of the available data published on adenomatoid odontogenic tumor (AOT) with special emphasis on the comparison of its variants.

METHODS

An electronic search was undertaken in July 2018. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm the diagnosis.

RESULTS

A total of 436 publications reporting 1558 cases were included, of which 739 follicular, 247 extrafollicular, and 30 peripheral AOTs. Impacted canine is associated with follicular AOTs in almost 70% of the cases. AOTs were more prevalent in females, in the second decade of life, in maxillae, in anterior region of the jaws, and most are asymptomatic, with a considerable number of lesions presenting cortical bone perforation. Most of the lesions were treated by enucleation. Some cases of recurrence were reported in the literature, but only one was well documented. No difference was found when comparing the clinical/radiological features of the follicular, extrafollicular, and peripheral variants.

CONCLUSIONS

Adenomatoid odontogenic tumor variants do not show distinctive clinical radiological features. Recurrence of AOT is very rare, which justify its conservative management.

Oct-4 and CD44 in epithelial stem cells like of benign odontogenic lesions

Benign epithelial odontogenic lesions are great clinical importance entities that develop in the jaws from the tissues that form teeth. It has been shown that benign and malignant tumors are present in a large number of tumor stem cells, which has great implications in the development of these lesions. Oct-4 and CD44 have been demonstrated as important markers for tumoral stem cells. The aim of this study was investigate the presence of stem cell markers Oct-4 and CD44 in benign epithelial odontogenic lesions. Twenty odontogenic keratocysts (OKC), 20 ameloblastomas (AMB) of the solid/multicystic type and 20 adenomatoid odontogenic tumors (AOT) were retrospectively analyzed for immunohistochemical detection of Oct-4 and CD44 in their epithelial component. All cases were positive for the two markers, with the majority exhibiting a high expression. Analysis of the expression of Oct-4 revealed no statistically significant differences (p = 0.406) between the lesions studied. Regarding CD44, there was a significant difference between the cases of AMB and AOT in relation with OKC, with the latter presenting a greater labelling (p = 0.034). No statistically significant correlation between Oct-4 and CD44 was observed in the lesions. In our findings, the presence of stem cell-like phenotype at various sites of the epithelial component of the odontogenic lesions was identified, suggesting its possible participation in histogenesis and differentiation without, however, exerting influence on the aggressiveness of the lesions.

An Extrafollicular Adenomatoid Odontogenic Tumor Mimicking a Periapical Cyst

Adenomatoid odontogenic tumor (AOT) is a rare noninvasive odontogenic tumor that occurs mostly in the second decade of life. Based on its tooth association, AOT can be classified into three categories of follicular, extrafollicular, and peripheral types; the follicular classification is considered as the most common type of AOT. This study reported a large extrafollicular case of AOT in a 40-year-old female. She was asymptomatic and tumor was detected accidentally by her dental practitioner. Since the panoramic radiograph showed a well-defined unilocular radiolucent lesion, we observed radiopaque spots within the lesion by using cone beam computed tomography. The extrafollicular type can mimic a periapical radiolucent lesion.

Odontogenic tumors: where are we in 2017 ?

Odontogenic tumors are a heterogeneous group of lesions of diverse clinical behavior and histopathologic types, ranging from hamartomatous lesions to malignancy. Because odontogenic tumors arise from the tissues which make our teeth, they are unique to the jaws, and by extension almost unique to dentistry. Odontogenic tumors, as in normal odontogenesis, are capable of inductive interactions between odontogenic ectomesenchyme and epithelium, and the classification of odontogenic tumors is essentially based on this interaction. The last update of these tumors was published in early 2017. According to this classification, benign odontogenic tumors are classified as follows: Epithelial, mesenchymal (ectomesenchymal), or mixed depending on which component of the tooth germ gives rise to the neoplasm. Malignant odontogenic tumors are quite rare and named similarly according to whether the epithelial or mesenchymal or both components is malignant. The goal of this review is to discuss the updated changes to odontogenic tumors and to review the more common types with clinical and radiological illustrations.

Pattern of distribution of odontogenic tumours in sub-Saharan Africa

OBJECTIVE

To analyse documented reports on odontogenic tumours (OTs) in sub-Saharan Black Africa and to create awareness of the need for more reports on this topic.

METHODS

There were 2,186 African cases of OTs presented at the International Association of Oral and Maxillofacial Pathologists (IAOP) Congress (Cape Town, South Africa) in 1998 that were added to 2,198 cases derived from reports published in the scientific literature from 1998 to date. The analysis undertaken included frequency distribution of available data on OTs that was listed in the 2005 World Health Organization (WHO) classification. The chi-square test was applied as appropriate.

RESULTS

A total of 4,384 cases of OTs from only 14 of 47 sub-Saharan Black African countries were analysed. Ameloblastoma was the OT most commonly reported, accounting for 74.2% of OTs (and 86.9% of category A OTs), followed by keratocystic odontogenic tumour (KCOT) (6.9%) and odontogenic myxoma (ODM) (4.9%). Malignant OTs were reported at a low frequency, of 1.4%. Nigeria contributed 38.7% of the cases of OT in this series.

CONCLUSIONS

Ameloblastoma is the commonest OT in sub-Saharan Africa and has a higher occurrence in male than in female subjects. With data on OTs not available from 33 of 47 sub-Saharan African countries, additional reports are needed.

The relative frequency of odontogenic tumors: A study of 376 cases in a Brazilian population

Background

Odontogenic tumors (OTs) are rare lesions, exclusive of the jaws, that are derived from epithelial and/or ectomesenchymal elements of the tooth-forming apparatus. Their biological behavior is heterogeneous, including hamartomatous tissue proliferation, benign nonaggressive and aggressive neoplasms, and malignant tumors with metastatic capacity. The aim of this study was to describe the relative frequency of odontogenic tumors in a Brazilian population. In addition, a review of the literature identified studies on odontogenic tumors that follow the 2005 World Health Organization.

Material and Methods

A total of 376 cases of odontogenic tumors from an oral pathology service were reviewed about age, gender, anatomic site and histologic diagnosis.

Results

Keratocystic odontogenic tumors (31.6%) were the most common, followed by ameloblastoma (28.5%), and odontoma (22.6%). The mean age was 32.2 years, and more than half the patients (52.1%) were in the second and third decades of life. The male to female ratio was 1:1.37, with a maxilla to mandible ratio of 1:2.08.

Conclusions

The variation in relative frequency of tumors observed among the several series, including the present study, is probably due in part to cultural differences between geographic areas but also to the study design.

Key words:Pathology, epidemiology, odontogenic tumors.

Adenomatoid odontogenic tumor: What is the true nature?

The Adenomatoid odontogenic tumor (AOT) is one of the most controversial benign odontogenic tumor, which has been known to the pathologists for the past 100 years. Since then the history, histogenesis and histopathologic designation of AOT remains a matter of debate. Some authors consider it as a true benign neoplasm while others consider it as a hamartoma and still others as an odontogenic cyst. Here we propose that the AOT should not be considered as a cyst because its true cystic nature remains questionable. We hypothesize that when the AOT arises from a change in REE covering of the impacted tooth, then it appears as cystic in nature & certainly not a true cyst by origin. Further studies on the histogenesis are required to change the nomenclature of AOT to adenomatoid odontogenic cyst (AOC).

A retrospective review of 61 cases of adenomatoid odontogenic tumour seen in five tertiary health facilities in Nigeria

INTRODUCTION

Adenomatoid odontogenic tumor (AOT) is a benign lesion originating from the dental lamina or its remnants. It is a relatively uncommon neoplasm representing about 3% of all odontogenic tumors. The aim of this study was to examine the clinical and radiological characteristics of AOTs in five major tertiary centres in Nigeria.

METHODS

Archival hospital-based data stores of five tertiary health facilities in Nigeria were accessed. Case files and biopsy records were retrieved to obtain relevant information. Data was collected according to a proforma for standardization and entered into and analysed using SPSS for Windows (version 20.0; SPSS Inc. Chicago, IL).

RESULTS

61 (4.5%) cases of AOT were documented. The age range was 8-46 years with a mean age of 20.4±9.9 years. Male: Female ratio was 1:1.3. The anterior maxilla had 34 (55.8%) cases and the anterior mandible had 20 (32.8%) cases. 40 (65.6%) follicular cases, 20 (32.8%) extra-follicular cases and 1(1.6%) extra-osseous case were found. 31 cases (61.1%) were associated with impacted teeth and the upper canine was involved in 19 (57.6%) cases.

CONCLUSION

This study showed AOT to be more common in the maxilla, more in females, most often associated with impacted canines, however, the suggestion of AOT being a "Two third tumour" was not observed in this study.

Follicular Adenomatoid Odontogenic Tumor in Mandible: A Rare Case Report

Adenomatoid odontogenic tumor (AOT) is a relatively rare, benign, hamartomatous, and cystic odontogenic neoplasm that was first described more than a century ago. The lesion still continues to intrigue experts with its varied histomorphology and controversies regarding its development. The present article describes a case of cystic AOT with an unusual histomorphology associated with an impacted 44 in a 21-year-old male.

The adenomatoid odontogenic tumour: an update of selected issues

The aim of this update was to present the recent notable progress within remaining questions relating to the adenomatoid odontogenic tumour (AOT). Selected issues that were studied included the following: (i) AOT history and terminology, (ii) the so-called peripheral AOT, (iii) AOT and the gubernaculum dentis and (iv) the so-called adenomatoid odontogenic cyst (AOC). The earliest irrefutable European case of AOT was described in 1915 by Harbitz as 'cystic adamantoma'. Recently, Ide et al. have traced two Japanese cases with irrefutable proof described by Nakayama in 1903. The so-called peripheral (gingival) variant of AOT seems to cover a dual pathogenesis, both an 'erupted intraosseous' and an 'extraosseous' (gingival) one. In 1992, we theorized that the generally unnoticed gubernaculum dentis (cord and canal) seems to be involved in the development of AOT. Ide et al. have concluded that the dental lamina in the gubernacular cord seems to be an embryonic source of the vast majority of AOTs. The suggestion by Marx and Stern to change the nomenclature of AOT to adenomatoid odontogenic cyst (AOC) is critically discussed. The present authors agree on the background of the work of several groups of researchers and WHO/IARC classifications that the biology of the follicular variant of AOT is already fully explained and does not make room for any change in diagnostic terms. Further, there is no reason to change terminology in this case where improvements or conditions to better clinical management are not an issue.

Cone beam computed tomography scanning and diagnosis for dental implants

Cone beam computed tomography (CBCT) has become an important new technology for oral and maxillofacial surgery practitioners. CBCT provides improved office-based diagnostic capability and applications for surgical procedures, such as CT guidance through the use of computer-generated drill guides. A thorough knowledge of the basic science of CBCT as well as the ability to interpret the images correctly and thoroughly is essential to current practice.

Odontogenic Cysts and Tumors

This article presents various odontogenic cysts and tumors, including periapical cysts, dentigerous cysts, odontogenic keratocysts, orthokeratinized odontogenic cysts, lateral periodontal cysts, glandular odontogenic cysts, ameloblastomas, clear cell odontogenic carcinomas, adenomatoid odontogenic tumors, calcifying epithelial odontogenic tumors, squamous odontogenic tumors, ameloblastic fibromas, ameloblastic fibro-odontomas, odontomas, calcifying cystic odontogenic tumors, and odontogenic myxomas. The authors provide an overview of these cysts and tumors, with microsopic features, gross features, differential diagnosis, prognosis, and potential diagnostic pitfalls.

Adenomatoid odontogenic tumor associated with an unerupted mandibular lateral incisor: a case report

Adenomatoid odontogenic tumor (AOT) is a rare, benign odontogenic tumor that predominantly appears in the second decade of life in female patients. Most AOTs occur in the anterior part of the maxilla and are usually associated with impacted anterior teeth. There are three types of AOT, follicular, extrafollicular, and peripheral, which are classified based on the location of the lesion and its association with the impacted tooth. We report a rare case of AOT associated with an impacted right mandibular lateral incisor in an 11-year-old female patient.

Cystic Adenomatoid Odontogenic Tumor

Adenomatoid Odontogenic Tumor (AOT) is a well-established benign epithelial lesion of odontogenic origin. Rightfully called "the master of disguise," this lesion has been known for its varied clinical and histoarchitectural patterns. Not only does AOT predominantly present radiologically as a unilocular cystic lesion enclosing the unerupted tooth (which is commonly mistaken as a dentigerous cyst) but the lesion also presents rarely with a cystic component histopathologically. We present one such unusual case of cystic AOT associated with an impacted canine, mimicking a dentigerous cyst. The present case aims to highlight the difference between cystic AOT and dentigerous cyst radiographically. The exact histogenesis of AOT and its variants still remains obscure. An attempt has been made to hypothesize the new school of thought regarding the origin of AOT.

Case Presentation of Concomitant and Contiguous Adenomatoid Odontogenic Tumor and Focal Cemento-Ossifying Dysplasia

A 24 year-old male was presented for the diagnosis of an asymptomatic bony expansion in relation to the right maxillary canine and first premolar. The unilocular radiolucent lesion with central foci of calcification had caused divergence of canine and first premolar roots without any resorption. This case report details a diagnosis of two distinct disease processes of different cellular origin namely, focal cemento-ossifying dysplasia and adenomatoid odontogenic tumor in a previously unreported concomitant and contiguous relationship. The diagnosis was determined by a combination of clinical, radiographic, histopathological and surgical evidence. This case highlights two points, first the need to examine all mixed radiolucent-radiopaque lesions with advanced imaging techniques to assess the number and extent of the lesions prior to treatment planning. Second a likely role of periodontal ligament as the tissue source for odontogenic epithelial cells and mesenchymal stem cells required for the development of odontogenic tumors and cemento-osseous dysplasias.

Adenoid ameloblastoma: clinicopathologic description of five cases and systematic review of the current knowledge

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of five cases of adenoid ameloblastoma.

STUDY DESIGN

Clinicopathologic data were gathered from medical records and compared with those compiled from a systematic review. Slides were also immunohistochemically stained for Ki-67, p16, p53, and cytokeratins (7, 8, 14, 18, and 19).

RESULTS

There were 3 males (60%) and 2 (40%) females. The mean age was 44 ± 10 years. Of the five adenoid ameloblastomas, 4 (80%) occurred in the posterior maxilla. Patients typically complained of asymptomatic swelling. All patients received surgical resection as primary therapy; 1 (20%) patient also received adjuvant radiotherapy. Recurrence was diagnosed in all patients. Immunohistochemically, the tumors stained focally positive for CK7, 8, 14, and 18 and diffusely positive for CK-19, p16, and p53. The mean Ki-67-positive cells were 72.4 ± 24.9 positive cells per high-power field (range 53-111).

CONCLUSIONS

To our knowledge, this is the largest series of adenoid ameloblastoma reported in the literature. Our data suggest that this entity demonstrates aggressive behavior characterized by a high likelihood of recurrence.

Adenomatoid Odontogenic Tumor (AOT) Arising from a Dentigerous Cyst: Literature Review and Report of a Case

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin composed of odontogenic epithelium in a variety of histopathological patterns. These lesions are usually solid but are occasionally cystic. AOT has been reported to occur in association with odontogenic cysts. Very few cases have been described that arise in association with a dentigerous cyst. A systematic search of the English-language medical literature in PubMed and Medline search (keywords adenomatoid odontogenic tumor, dentigerous cyst) data bases revealed only ten such cases. The present case is very unique, exceptional and first of this kind that occurred in the posterior mandible associated with an impacted lower first premolar in a 19-year old female patient. The intraosseous follicular AOT, as this case reported here, frequently resemble dentigerous cysts. There is an uncertainty whether the lining of an associated cyst represents a true dentigerous cyst, cystic change within an AOT or may represent a distinct entity. We believe that this case represents an odontogenic cyst with neoplastic change. Hence, in such cases, the final diagnosis should be made on the basis of histological examination of extensive tissue sampling of entire excised tissue specimen. Further studies to determine whether the AOT derived from an odontogenic cyst could represent a distinct variant are to be done.

Squamous Odontogenic Tumor: Literature Review Focusing on the Radiographic Features and Differential Diagnosis

Since its first publication in 1975, the squamous odontogenic tumor remains the rarest odontogenic lesion, with around 50 cases in the English-language literature in which the microscopic characteristics are frequently very well demonstrated. However, articles which discuss the radiographic aspects are scarce, especially with emphasis on the differential diagnosis. The present treatise proposes an assessment of jaw lesions with the same radiographic characteristics of the squamous odontogenic tumor to clarify the main findings for dental clinicians during routine diagnosis.

Dentigerous cyst or adenomatoid odontogenic tumor: clinical radiological and histopathological dilemma

Adenomatoid odontogenic tumor (AOT) is a well-recognised slow growing benign tumor derived from complex system of dental lamina or its remnants. This lesion is categorised into three variants of which the more common variant is follicular type which is often mistaken for dentigerous cyst. We present a case of AOT in a 14-year-old male who was misdiagnosed as dentigerous cyst. Clinical radiological and therapeutic characteristics of the case are commented on in detail.

Characteristic features of the adenomatoid odontogenic tumour on cone beam CT

OBJECTIVES

To illustrate characteristic features of adenomatoid odontogenic tumour (AOT) on CBCT.

METHODS

The archived CBCT and panoramic radiographs of eight patients histopathologically diagnosed as AOT were analysed. The radiographic features displayed on both radiographic images were carefully described and compared.

RESULTS

All eight AOT cases presented as unilocular and well-demarcated lesions on both CBCT and panoramic images. CBCT images displayed three-dimensional interpretation of AOT lesions, especially the detailed intralesional radiopacities. Numerous discrete radiopaque foci scattered in the lesion with evident contrast to the radiolucent background could be considered as one of the characteristic features of AOT on CBCT.

CONCLUSIONS

Compared with panoramic radiography, CBCT seems to possess better potential in diagnosing AOT.