Variants of the adenomatoid odontogenic tumor with a note on tumor origin

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.

Adenomatoid Odontogenic Tumor of the Maxilla in a 13-year-old Patient: A Rare Case Report with a Review of Literature

Background

The AOT is an atypical tumor of odontogenic origin that comprises about 0.1% of jaw tumors and cysts as well as up to 3% of odontogenic tumors (OTs).

Aim and objective

This review describes the clinical, radiographical, histopathological, and immunohistochemical properties of adenomatoid odontogenic tumor (AOT) and reports an occurrence of an AOT in a boy, 13 years of age.

Case description

A male, 13 years of age, presented with a swelling with respect to the left maxilla, painless, and with obvious facial asymmetry. The orthopantomogram and computed tomography scan revealed a large unilocular radiolucency in the left maxilla with permanent lateral incisor embedded within the lesion and permanent canine pushed away from its normal position. After complete enucleation of the cyst under local anesthesia and extraction of associated impacted permanent teeth and retained deciduous teeth related to the lesion, the defect was filled with a bone graft and closed. Postoperative follow-up was uneventful.

Conclusion

An accurate diagnosis should be established through clinical, radiographical, and pathological correlations in order to be able to differentiate AOT from other conditions for early diagnosis.

Clinical significance

This report highlights the salient features of the AOT to be able to correctly diagnose and manage the lesion.

How to cite this article

Kamble A, Shimpi MR, Dash JK, et al. Adenomatoid Odontogenic Tumor of the Maxilla in a 13-year-old Patient: A Rare Case Report with a Review of Literature. Int J Clin Pediatr Dent 2021;14(4):596–600.

Imaging peculiarities of gubernaculum tracts in molars as accessional teeth on CT

Objectives

The shapes of gubernaculum tracts (GTs) in molars as accessional teeth remain unidentified. To elucidate imaging peculiarities of GTs in molars with aging on multidetector‐row computed tomography (MDCT).

Material and methods

This retrospective study was conducted using CT images, including maxillary and mandibular molars, with no abnormal findings from 239 patients. Shapes of alveolar bone, GTs, and dental sacs of the maxillary and mandibular molars were analyzed multi‐sectionally. Correlations between 2‐ and 3‐dimensional imaging figures of GTs in molars and chronological age or stage of molar formation were analyzed.

Results

Some forms of GTs in maxillary and mandibular third molars were observed. In the early stage, GTs were visualized as bone defect lines on the dentition and grooves on the mesial alveolar crest continuous with the dental sac to mesial tooth bud. GTs of the third molar formed a J‐shape in maxillary teeth and Y‐shape in mandibular teeth in the middle stage, as alveolar bone around the GT developed. In the mature stage, the course of the GT changed to straight and perpendicular. Some GT forms were also identified in first and second molars. Significant correlations were found between GT alterations and chronological age or stage of molar formation. Moreover, tracts continuing from the distal side of mandibular third molars were detected.

Conclusions

This paper describes the peculiarities and process of progression for GTs in molars, and the existence of tracts continuing from the distal side of mandibular third molars, unlikely dentition with deciduous predecessors. These preliminary data should prove beneficial for studies focusing on GTs in molars.

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.

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.

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.

Trauma to Tumor: A Hunt of Adenomatoid Odontogenic Tumor-A Rare Case Report

Tumors and tumor-like growths arising from odontogenic tissues constitute a heterogeneous group of interesting lesions, as they display the various inductive interactions that normally occur among the embryologic components of the developing tooth germ. Adenomatoid odontogenic tumor is a benign tumor, most common in the maxilla, characterized by slow, progressive, painless growth of firm consistency, the size of which usually does not reach large proportions. They are of three types: extrafollicular, follicular, and peripheral. It usually develops around or overlaps adjacent teeth.

Significance and usefulness of imaging characteristics of gubernaculum tracts for the diagnosis of odontogenic tumors or cysts

We aimed to determine the significance and usefulness of imaging characteristics of gubernaculum tracts (GT) for the diagnosis of odontogenic tumors or cysts. This was a retrospective analysis of relationships between odontogenic or non-odontogenic tumors or cysts and the GT that were visualized using multi-detector computed tomography (MDCT). The relationship between the size of a mass and expansion of the GT in all odontogenic tumors or cysts to which GTs were contiguous on MDCT, was statistically analyzed. Intact or expanded GTs were detected in MDCT images on the top of almost all odontogenic tumors or cysts, but not on non-odontogenic tumors or cysts. Characteristic image findings regarding the relationship between the GT and the odontogenic mass were detected for the respective odontogenic tumors or cysts in which the GTs were contiguous to the mass on MDCT. In ameloblastomas, expansion of the GTs significantly and very strongly correlated with tumor size (r = 0.741, p = 0.0001), but this correlation was very weak in dentigerous cysts (r = 0.167, p = 0.028) and there was no correlation between these parameters in odontogenic keratocysts (r = -0.089, p = 0.557). The imaging characteristics of GTs at the top of masses should be very useful for both the differential diagnosis of the pathological diagnosis of odontogenic masses and for differentiation between odontogenic and non-odontogenic masses.

Aggressive adenomatoid odontogenic tumor of the mandible: A rare case report and review of the literature

Adenomatoid odontogenic tumor (AOT) is a relatively rare and distinct odontogenic tumor that is exclusively odontogenic epithelium in origin. Although considerable numbers of reports are available with regard to the clinical and histological spectrum of AOT, very few have highlighted its rare aggressive nature. This article focuses on an AOT causing jaw swelling in the mandibular anterior region with cortical plate expansion and perforation, root resorption and paresthesia. The present case had remarkably unusual clinical and radiographic features that distinguished it from most conventional AOTs and supported its neoplastic nature.

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).

Rare presentation of adenomatoid odontogenic tumor in a pediatric patient: a case report

The adenomatoid odontogenic tumor (AOT) is a painless benign tumor with slow growth, usually asymptomatic. It has three variants: follicular, extrafollicular, and peripheral. In the follicular type, the tumor is associated with an impacted tooth, and maxillary canines are the most frequently affected. Association with primary teeth is very rare. Treatment consists essentially in a total lesion enucleation. The objective of this paper is to present the clinical case of a 7-year-old female patient with an adenomatoid odontogenic tumor associated with the crown of the left lower deciduous canine (73), dislodging it to the mandibular base and consequently shifting and also impacting the permanent lower canine (33). The lesion was treated with careful enucleation, preserving the permanent canine, which then had its eruption path released favoring its migration to an ideal position.

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.

A case report and short review on changing trends in the site of occurrence of adenomatoid odontogenic tumor: Unravelling the past 15 years

Adenomatoid odontogenic tumor (AOT) is an uncommon benign odontogenic lesion, with debatable histogenesis and variable histopathology. A systematic and diverse insight into the evolution, clinical presentation, histology, and immunohistochemical findings of this lesion is reviewed and presented. We reviewed the data published from 2000 to 2014 of approximately 255 cases that revealed a significant change in the incidence of predominant site involved, in contrast to the findings published by Reichart. We have also included the chronological order of events leading to the coining of the term AOT, which shows the curiosity that has been dedicated to understanding the lesion. Immunohistochemistry is considered to be a hallmark in pathology for learning the molecular pathogenesis and giving a correct final diagnosis. Several markers have been used to investigate and understand this lesion, and a compilation of the findings has been tabulated.

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.

A spatial association between odontomas and the gubernaculum tracts

OBJECTIVES

The purpose of this study was to identify the spatial relationship and/or association between odontomas and the gubernaculum tract or the dental sac and the characteristic findings for radiographic diagnosis of odontomas.

STUDY DESIGN

The visualizations of the odontomas and the gubernaculum tract were retrospectively analyzed using cone beam computed tomography or multidetector computed tomography.

RESULTS

Most of odontomas were within the gubernaculum tract or dental sac of unerupted permanent teeth on computed tomography. In some odontomas, the gubernaculum tract existed as a well-defined low density tract extending from the top of odontomas on computed tomography.

CONCLUSIONS

A close spatial relationship and/or association between odontomas and the gubernaculum tract or dental sac on computed tomography may be used as one of the criteria for radiographic diagnosis of odontomas. Development of odontomas may be associated with the gubernaculum tract or dental sac of unerupted permanent teeth.

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.

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.

Multiple Pathology in a Single Lesion: AOT Associated with Dentigerous Cyst

Odontogenic cysts and tumors are quite common occurrences in jaw bones, although both of them occurring together are rare. The epithelial lining of odontogenic cyst has a potential to transform into neoplastic conditions like squamous cell carcinoma and mucoepidermoid carcinoma, and odontogenic tumors like ameloblastoma and adenomatoid odontogenic tumor. However, the frequency of such cases being encountered is very less. Here, we report a case of adenomatoid odontogenic tumor (AOT) associated with a dentigerous cyst around the crown of an unerupted lateral incisor (follicular variant), in a 14-year-old boy. We also attempt to unravel its mechanism of cytodifferentiation and tumor progression. The origin and nature of such kind of lesions (i.e., independent development of multiple pathologies as a single lesion in a single location, single pathology giving rise to another pathology or a distinct entity/new variant) cannot be explained with certainty at this point of time. The molecular mechanism of tumor development needs to be further elucidated in order to conclude that a different entity called 'hybrid' AOT exists.

Plexiform unicystic ameloblastoma: a rare variant of ameloblastoma

The term plexiform unicystic ameloblastoma refers to a pattern of epithelial proliferation that has been described in cystic cavity. Because of unilocular presentation, it is commonly misdiagnosed as an odontogenic cyst. However, they may often behave clinically as biologically aggressive tumors. These tumors show high incidence of cortical perforation, tooth resorption and a high rate of recurrence after simple enucleation. This paper aims to provide an insight into this biologically distinct entity. A literature review on the topic has been added along with a case report highlighting the approach of diagnosis and management of such ameloblastomas.

Extensive Adenomatoid Odontogenic Tumor of the Maxilla: A Case Report of Conservative Surgical Excision and Orthodontic Alignment of Impacted Canine

The present report describe the surgical therapy, clinical course, orthodontic treatment and morphological characteristics of an adenomatoid odontogenic tumor in the maxilla of an 11-year-old patient. The cystic tumor filled the maxillary sinus and involved a tooth. Marsupialization was accompanied by partial enucleation and applied traction to the affected tooth by a fixed orthodontic appliance. Healing was uneventful and no local recurrence was observed during a 1-year period of follow-up control.

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.

Adenomatoid odontogenic tumour in a 20-year-old woman

Adenomatoid odontogenic tumour is a relatively rare and distinct odontogenic tumour that is exclusively odontogenic epithelium in origin. It comprises 3% of all odontogenic tumours. This report describes the surgical therapy, clinical course and morphological characteristics of an adenomatoid odontogenic tumour that developed in the left maxilla of a 20-year-old patient.

Adenomatoid odontogenic tumour in a 20-year-old woman

Adenomatoid odontogenic tumour is a relatively rare and distinct odontogenic tumour that is exclusively odontogenic epithelium in origin. It comprises 3% of all odontogenic tumours. This report describes the surgical therapy, clinical course and morphological characteristics of an adenomatoid odontogenic tumour that developed in the left maxilla of a 20-year-old patient.

Adenomatoid odontogenic tumour in mandible in a 14-year-old boy

A 14-year-old boy reported with a painless swelling over the right anterior mandible with missing right canine tooth. The lesion was diagnosed as 'central follicular adenomatoid odontogenic tumour' and excised surgically under general anaesthesia. The patient was on a year-long clinical and radiographical follow-up.

Peripheral adenomatoid odontogenic tumour - is it really peripheral?: a case report

A Peripheral Adenomatoid Odontogenic Tumour (PAOT) is quite a rare entity which has been infrequently reported in the literature. These uncommon clinical variants of an Adenomatoid Odontogenic Tumour (AOT), typically manifest as a soft tissue mass of the gingiva, which mimick a common epulis, but yet have an identical histopathologic presentation as their intraosseous counterpart. These lesions, though they are indolent in nature, have a tendency to cause well defined deep bony pockets. Only fourteen cases have been adequately documented so far. We are reporting a case of a PAOT of the anterior maxillary gingiva, with a periodontal bone defect in a 12 year old girl. The relevant literature has been briefly reviewed, with an insight into the probable origin of PAOTs with bony defects.

Current concepts and occurrence of epithelial odontogenic tumors: I. Ameloblastoma and adenomatoid odontogenic tumor

Ameloblastomas and adenomatoid odontogenic tumors (AOTs) are common epithelial tumors of odontogenic origin. Ameloblastomas are clinico-pathologically classified into solid/multicystic, unicystic, desmoplastic, and peripheral types, and also divided into follicular, plexiform, acanthomatous, granular types, etc., based on their histological features. Craniopharyngiomas, derived from the remnants of Rathke's pouch or a misplaced enamel organ, are also comparable to the odontogenic tumors. The malignant transformation of ameloblastomas results in the formation of ameloblastic carcinomas and malignant ameloblastomas depending on cytological dysplasia and metastasis, respectively. AOTs are classified into follicular, extrafollicular, and peripheral types. Ameloblastomas are common, have an aggressive behavior and recurrent course, and are rarely metastatic, while AOTs are hamartomatous benign lesions derived from the complex system of the dental lamina or its remnants. With advances in the elucidation of molecular signaling mechanisms in cells, the cytodifferentiation of epithelial tumor cells in ameloblastomas and AOTs can be identified using different biomarkers. Therefore, it is suggested that comprehensive pathological observation including molecular genetic information can provide a more reliable differential diagnosis for the propagation and prognosis of ameloblastomas and AOTs. This study aimed to review the current concepts of ameloblastomas and AOTs and to discuss their clinico-pathological features relevant to tumorigenesis and prognosis.

Adenomatoid odontogenic tumor: retrospective study of 15 cases with emphasis on histopathologic features

Adenomatoid odontogenic tumor (AOT) is an uncommon benign epithelial lesion of odontogenic origin and, thus far, only few studies regarding the frequency of its many histopathologic features have been published in the literature. Thus, the aim of this study was to perform a retrospective analysis in a case series of AOT, with emphasis on the histopathological features. Fifteen cases of AOT were studied considering their clinical, radiographic and histopathologic aspects. Twelve cases affected females and the mean age was 16.2 years. The anterior maxilla was the most common site (66.6 %) and radiographically most cases showed a unilocular radiolucency with well-defined borders (57.1 %). Histologically, most cases exhibited predominantly a solid growth pattern (46.7 %) or a similar proportion of solid and cribriform patterns (46.7 %). Eosinophilic amorphous material ("tumor droplets") was found in all cases (100 %). Most tumors showed duct-like spaces (93.3 %) and convoluted structures (60.0 %) whereas a minor proportion of cases presented calcifying epithelial odontogenic tumor (CEOT)-like areas (26.7 %). Variable amounts of calcified material were found in most AOTs (80.0 %) whereas osteodentin and perivascular hyalinization were seen only rarely (6.7 % each one). Five (33.3 %) cases had areas mimicking a dentigerous cyst and most of these were diagnosed in females (80.0 %). Regarding the histopathologic features, our results suggest that AOTs usually show predominance of solid pattern or a similar proportion of solid and cribriform patterns while osteodentin and perivascular hyalinization are rarely seen in these tumors. In addition, areas mimicking a dentigerous cyst and CEOT-like areas are relatively infrequent findings in AOTs.

Critical evaluation of the radiological and clinical features of adenomatoid odontogenic tumour

OBJECTIVES

The aim of this study was to evaluate the radiological and clinical features of adenomatoid odontogenic tumours (AOTs).

METHODS

A total of 272 cases (267 from the English-language literature and 5 new cases) were analysed with special emphasis on their radiological features.

RESULTS

The patients' ages at time of diagnosis ranged from 3 years to 82 years (mean 18.4 years). The maxilla-to-mandible ratio was 1.7:1. Mandibular lesions were significantly more frequent among patients older than 16 years (p = 0.032). Expansion of the cortex was significantly more prominent among patients older than 16 years (p = 0.045). There was a positive correlation between the size of the lesion and the age of the patient at the time of diagnosis (p = 0.016). The size was also associated with increased root resorption (p < 0.001), ill-defined borders (p < 0.001), expansion (p < 0.001) and perforation of the cortex (p < 0.001). Small opacities were present in 77% of lesions and were associated with expansion of the cortex (p = 0.043). The significant radiological features in patients aged 30 years and above were root resorption (p = 0.013) and lesions crossing the midline (p = 0.019).

CONCLUSIONS

The size of an AOT is influenced by the patient's age. It is also associated with root resorption, ill-defined borders, expansion and perforation of the cortex, but it cannot be ruled out that those changes reflect a longer duration of the lesion.

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.

Adenomatoid odontogenic tumor: As an unusual mandibular manifestation

Adenomatoid odontogenic tumor (AOT) is a rare odontogenic tumor which is often misdiagnosed as odontogenic cyst and accounts for about 1% until 9% of all odontogenic tumors. It is predominantly found in young and female patients, located more often in the maxilla in most cases associated with an unerupted permanent tooth. It is a benign (hamartomatous), noninvasive lesion with slow but progressive growth. There are three variants of AOT: follicular, extrafollicular, and peripheral. We report a rare case of follicular-type AOT in the mandible of a 14-year-old male patient who presented with right -sided jaw swelling.

Adenomatoid odontogenic tumor: A unique report with histological diversity

Odontogenic tumors are a group of heterogeneous lesions, features of which have been catalogued for several decades. Adenomatoid odontogenic tumor (AOT) is a relatively rare and distinct odontogenic tumor that is exclusively odontogenic epithelium in origin. Although considerable number of reports is available with regard to the clinical and histological spectrum of AOT, very few have highlighted its varied histological presentations. Therefore, this article focuses on the assorted histoarchitectural patterns of AOT.

Bilateral adenomatoid odontogenic tumour of the maxilla in a 2-year-old female--the report of a rare case and review of the literature

Multifocal odontogenic lesions are uncommon and have only been observed in conditions associated with known genetic mutations. To the best of our knowledge, only two cases of multifocal adenomatoid odontogenic tumours (AOT) have previously been reported in the literature. In this study, we report the first case of a bilateral, separate AOT in the maxilla in the midline in a 2-year-old female. The patient presented with bilateral expansile masses in the maxilla on either side of the midline which had been present for 6 months. She was asymptomatic and had occasional difficulty in breathing. The tumour was diagnosed as AOT and was surgically enucleated along with the associated teeth. The patient recovered well and has been on recall for 5 years. The follow-up panoramic radiograph made a fortnight ago revealed evidence of three new radio-opaque lesions with an associated tooth in the region of the anterior mandible, the premolar region of the right maxilla and the molar region of the left maxilla. To acquire additional information about AOT, all reports regarding AOT cited in 'PubMed' from 1995 onward were reviewed and the incidence, clinical features, radiographic features and management of AOT are discussed in this study.

Adenomatoid odontogenic tumor associated with dentigerous cyst in posterior maxilla: A case report and review of literature

Adenomatoid odontogenic tumor (AOT)-a benign (hamartomatous) lesion of odontogenic origin-is an uncommon tumor which affects young individuals with a female predominance, mainly in the second decade. This lesion is most commonly located in the anterior maxilla and is usually associated with an impacted canine tooth. This is a case report of a 39-year-old female patient presented with a large AOT of the posterior maxilla associated with an impacted second molar - a very rare situation.

Adenomatoid odontogenic tumor associated with dentigerous cyst of the maxillary antrum: A rare entity

Adenomatoid odontogenic tumor (AOT) is an uncommon tumor of odontogenic origin composed of odontogenic epithelium in a variety of histoarchitectural patterns. Most cases are in females and have a striking tendency to occur in the anterior maxilla. However, AOT of the maxillary antrum is extremely rare. A 25-year-old female presented with a large radiolucent lesion associated with the crown of an unerupted canine located in the maxillary antrum, which was clinically diagnosed as dentigerous cyst. The microscopic examination revealed the presence of AOT in the fibrous capsule of a dentigerous cyst. Very few cases of AOT associated with dentigerous cyst have been reported till date. A case of gigantic AOT that occupied the maxillary sinus and associated with dentigerous cyst is described. Also, an attempt has been made to determine whether the AOT derived from the dentigerous cyst could represent a distinct hybrid variety.

Development and growth of adenomatoid odontogenic tumor related to formation and eruption of teeth

The number of published cases of adenomatoid odontogenic tumor (AOT) has steadily increased, and about half were reported in Asian populations. Although the clinicopathologic profile of AOT has been extensively reported, factual knowledge of its pathogenesis is rudimentary at best, and there is controversy as to precisely which odontogenic epithelium it arises from. AOT is a successional tooth-associated lesion which develops during the mixed dentition. The permanent successor differs from its deciduous predecessor in that it has an eruptive pathway from the dental follicle to the gingiva, the gubernaculum dentis. With this background in mind, the present review focuses mainly on the early development of AOT. We successfully demonstrated a close spatial relationship between AOT and the gubernaculum dentis in a typical case. From further observations of the same AOT in which an enclosed permanent canine showed enamel hypoplasia, it is possible to pinpoint areas around the crown of a developing successional tooth in continuity with the gubernaculum dentis as starting points. In addition, we discuss the unifying histogenetic concept of three clinical variants, namely, pericoronal (follicular), extracoronal (extrafollicular), (see Article note) and peripheral.

Study on the origin and nature of the adenomatoid odontogenic tumor by immunohistochemistry

The adenomatoid odontogenic tumor (AOT) is a clinically benign lesion. Discussions about the AOT hamartomatous or neoplastic nature, and the probable odontogenic epithelial cell it originates from still exist. This research aimed to study and discuss the subject by the immunohistochemical detection of cytokeratins, laminin, collagen IV, PCNA and p53 in 8 tumor samples and 8 dental follicle samples containing reduced enamel epithelium. The results have shown that CK14 labelling indicated differentiation grades for secreting ameloblasts or ameloblasts in the post-secreting stage in the adenomatoid structure of AOT. Laminin, found on the luminal surface of adenomatoid structures, was compatible with the reduced enamel epithelium during the "protective stage of amelogenesis". PCNA specifically labelled the spindled areas and peripheral cords of the AOT, indicating that these areas are responsible for tumor growth. After considerations about pathogenesis, the authors suggested that the nature of AOT is hamartomatous with histogenesis from the reduced enamel epithelium.

Adenomatoid odontogenic tumour: tumour or a cyst, a histopathological support for the controversy

Adenomatoid odontogenic tumour (AOT) is a well-established odontogenic tumour with various clinicopathological variants. AOT quite frequently mimics an odontogenic cyst commonly a dentigerous cyst. Histologically a cystic component of AOT has been described in the literature. In the present paper we review the literature for the AOTs arising in an odontogenic cyst and add to the literature a case of cystic AOT. The present review is aimed to provide an insight to the varied demographic profile, clinical behavior and prognosis of cystic variant of AOT.

[Benign epithelial odontogenic tumors]

The group of benign epithelial odontogenic tumors consists of the four member types of the ameloblastoma family (solid/multicystic, extraosseous/peripheral, desmoplastic, unicystic), squamous odontogenic tumors, calcifying odontogenic tumors, adenomatoid odontogenic tumors, and keratocystic odontogenic tumors, the former "keratocysts" that were recently reclassified by the World Health Organization and are now regarded as tumors. The latter are by far the most frequent tumors in this group, followed by solid/multicystic ameloblastoma. Although the etiology of these lesions is still unknown, a close relationship to normal tooth development is obvious, which is partially imitated by some tumors. Despite some similarities to each other, at least in part, the biological behavior of these lesions is quite different, as are treatment modalities. The diagnosis is essentially based on localization (intraosseous vs. extraosseous/peripheral) and histology, whereupon the correlation of histological findings with radiographic morphology may be of additional diagnostic value. Because of the range of variation, immunohistochemical investigations are not helpful in diagnosing a particular case.

Adenomatoid odontogenic tumor (AOT) originating in a unicystic ameloblastoma: a case report

The follicular variant of the adenomatoid odontogenic tumor (AOT) is thought to originate from the reduced enamel epithelium of the dental follicle. The origin of the extra-follicular variant however, remains less clear. This paper presents a case of an extra-follicular AOT, which we believe originated from the epithelial lining of a unicystic ameloblastoma, and reviews the literature. The available evidence seems to indicate that some extra-follicular AOTs might arise as secondary phenomena within pre-existing odontogenic cysts or cystic tumors.

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

BACKGROUND

Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT.

MATERIAL AND METHODS

Cases published in the literature and cases in files of co-authors were included.

RESULTS

550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2-7.1%).

CONCLUSIONS

This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour.