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Adenoid ameloblastoma is a newly recognized epithelial odontogenic tumor. Herein, we present the case of a 24-year-old male patient who exhibited swelling in the anterior region and right hemi-mandible. Computed tomography demonstrated the presence of a hypodense osteolytic lesion associated with an impacted tooth. Based on the clinical hypotheses of the dentigerous cyst, odontogenic keratocyst, and ameloblastoma, an incisional biopsy was performed, and the diagnosis of ameloblastoma was rendered. A surgical resection of the tumor was performed. Histopathological examination of the specimen revealed typical areas of ameloblastoma associated with ductiform structures and cell proliferation in a solid storiform pattern, features resembling those found in adenomatoid odontogenic tumor. Based on these findings, the diagnosis of adenoid ameloblastoma was rendered. The accurate diagnosis of this locally infiltrative tumor is essential due to its similarity to other odontogenic neoplasms., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Adenomatoid odontogenic tumor (AOT) is an infrequent odontogenic tumor that typically occurs in adolescent females, usually in the anterior maxilla. There is a controversy about it being a tumor or a hamartoma. It presents clinically as a slowly progressive entity that shows a good prognosis with conservative surgical management. It shows three clinicopathological types: follicular, extrafollicular, and peripheral. This article describes a follicular variety of AOT. An 18-year-old female presented with diffuse intraoral swelling in the maxillary anterior region. An intraoral periapical radiograph (IOPA) revealed a single large pericoronal radiolucency related to the impacted right maxillary lateral incisor. Histopathological evaluation confirmed the diagnosis, and the tumor was treated surgically by enucleation., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Dangore-Khasbage et al.)

Adenomatoid odontogenic tumor (AOT) is a rare, asymptomatic, slow-growing benign tumor that can be divided into three variants: follicular, extrafollicular, and peripheral. By treating AOT using an enucleation and curettage approach, recurrence can be avoided. We report a case of a 24-year-old female who presented with a lump in the right mandibular premolar area along with diastema between displaced teeth #43 and #44 and was diagnosed with extrafollicular AOT. The patient was managed with enucleation-curettage surgery without additional bone graft procedure along with routine follow-up. A successful outcome without recurrence was achieved, and diastema closure with repositioning of the displaced teeth did not require orthodontic treatment. AOT should be managed via enucleation and curettage to obtain successful outcomes without recurrence. Spontaneous bone regeneration following enucleation can be achieved without guided bone regeneration. Also, diastema closure and repositioning of displaced teeth can occur without orthodontic interventions through physiologic drift.

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

The objective of this study was to review the clinical, radiologic, and histologic aspects of cases of dentigerous cysts metamorphosing into different entities along with comments on the molecular factors involved in the process. A series comprising 8 cases of dentigerous cysts was performed retrospectively along with a comprehensive literature review. Two cases of dentigerous cyst converting into mucous metaplasia were included, out of which one case was transformed into ameloblastoma after a year. The other two cases were reported as acanthomatous and unicystic ameloblastoma, whereas four transitioned to AOT. The complete review of cases and literature with molecular profiling concluded that the lining of dentigerous cysts has the potential for transforming into benign odontogenic tumors. Therefore, a careful clinical and histopathological examination is crucial for the correct diagnosis. Also, a thorough molecular understanding of the cystic lining is required., Competing Interests: Conflicts of Interest/Competing InterestsThe authors declare that they have no known conflict of interest., (© Association of Otolaryngologists of India 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Competing Interests: The authors have no conflicts of interest relevant to this article.

Introduction: Odontogenic tumors encompass a heterogeneous group of lesions that range from hamartomatous lesions to malignancy. Considerable variation in histologic presentation can mislead their accurate diagnosis and categorization. Ameloblastoma is generally well understood and is easy to diagnose but there has been a constant change in the classification systems ever since Broca classified odontogenic tumors in the year 1867. Over the years, it has been modified by the World Health Organization with many additions and omissions. This dynamic change is based on the result and conclusions of molecular and genetic studies with the last modification in 2017. Case Report: We present two cases of females aged 32 and 60 years who reported with facial swellings, revealed the presence of distinct histopathological findings and were diagnosed as ameloblastoma with dentinoid or adenoid ameloblastoma. Literature search revealed dearth of distinct forms of ameloblastoma that show the formation of duct like structures and dentinoid. Conclusion: It is interesting to highlight such cases as the biological behavior is still unexplored due to paucity of relevant studies and follow up of patients. Understanding the pathogenesis and the histopathological characteristics of the newer entities will enable the prompt diagnosis, treatment plan and expanding the spectrum of the lesions., Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03534-6., Competing Interests: Conflicts of interest/Competing Interests (include appropriate disclosures)NA., (© Association of Otolaryngologists of India 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Background: Adenoid ameloblastoma (AdAM) is a frequently recurrent tumor that shows hybrid histological features of both ameloblastoma and adenomatoid odontogenic tumor (AOT). AdAM is expected to be classified as a new subtype of ameloblastoma in the next revision of the World Health Organization (WHO) odontogenic tumor classification. However, whether AdAM is a histologic variant of ameloblastoma or AOT remains unclear. To establish a new category, genetic evidence indicating the tumor category is necessary., Methods: We present a case of a 23-year-old Japanese woman with AdAM who underwent genetic/DNA analysis for ameloblastoma-related mutation using immunohistochemical staining, Sanger sequencing, and next-generation sequencing (NGS) analyses with reliable clinicopathological evidence., Results: Immunohistochemical expression of BRAF p.V600E was diffusely positive for both ameloblastoma- and AOT-like components. Sanger sequencing and NGS analyses showed missense mutations in BRAF p.V600E (c.1799T > A), a gene that is commonly altered in ameloblastomas but not in KRAS, another gene associated with AOT., Conclusion: This case report is the first to provide genetic evidence on the ameloblastomatous origin of AdAM with a BRAF p.V600E mutation. A larger series of AdAM groups' molecular testing is needed to aptly classify them and prognosticate the best treatment., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: This study aimed to investigate the differentiation of ameloblastic-like cells and the nature of the secreted eosinophilic materials in adenomatoid odontogenic tumors., Methods: We studied histological and immunohistochemical characteristics of 20 cases using: cytokeratins 14 and 19, amelogenin, collagen I, laminin, vimentin, and CD34., Results: Rosette cells differentiated into ameloblastic-like cells positioned face-to-face, displaying collagen I-positive material between them. Epithelial cells of the rosettes can differentiate into ameloblastic-like cells. This phenomenon probably occurs due to an induction phenomenon between these cells. The secretion of collagen I is probably a brief event. Amelogenin-positive areas were interspersed by epithelial cells in the lace-like areas, outside the rosettes and distant from the ameloblastic-like cells., Conclusions: There are at least two types of eosinophilic material in different areas within the tumor, one in the rosette and solid areas and another in lace-like areas. The secreted eosinophilic material in the rosettes and solid areas is probably a product of well-differentiated ameloblastic-like cells. It is positive for collagen I and negative for amelogenin, whereas some eosinophilic materials in the lace-like areas are positive for amelogenin. We hypothesize that the latter eosinophilic material could be a product of odontogenic cuboidal epithelial or intermediate stratum-like epithelial cells., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The process of odontogenesis is complex involving epithelial-mesenchymal interactions, along with the molecular signalling pathways triggering the initiating process. The triggering factors and cells precisely involved in the pathogenesis of odontogenic cysts and tumors are unknown. There is a vast array of biomarkers used to stain different sites, thereby helpful in diagnosing and evaluating the prognosis of these cysts and tumors. In the following study, Anti Apoptotic survivin expression patterns were assessed quantitatively in 48 samples (12 each) of Reduced Enamel Epithelium, Adenomatoid Odontogenic Tumor, Odontogenic Keratocyst and Ameloblastoma., Aim: The Aim of this study is to assess the anti-apoptotic survivin expression in Reduced Enamel Epithelium, Adenomatoid odontogenic tumour, Odontogenic Keratocyst and Ameloblastoma., Materials and Methods: The present study is carried out with 12 samples in each group. Routine hematoxylin and eosin staining was performed for confirmatory diagnosis. Later Immunohistochemistry was performed using survivin antibody. Survivin protein expression was analyzed using the parameters like location, intensity, percentage of cells positivity with survivin protein and extent of staining. With the help of Olympus BX 43 microscope, with ProgRes microscope camera, the 48 slides obtained were examined. The region of interest was selected in each slide and number of cells positively stained was counted. Data was analyzed using SPSS software version 23. Descriptive for scale data, results were analysed by using ANOVA with Chi-square test for intergroup comparison., Results: The results showed significant P value <0.05. Expression of survivin was highest in Ameloblastoma, followed by Odontogenic keratocyst, Adenomatoid odontogenic tumor, and Reduced Enamel Epithelium., Conclusion: Survivin was involved in the inhibition of apoptosis as well as the detailed understanding of the biological behaviour of odontogenic cysts and tumours, thereby increasing therapeutic approaches., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Journal of Oral and Maxillofacial Pathology.)

Background: The occurrence of hybrid odontogenic lesions with two or more morphologically distinct components is a rare phenomenon and poses a diagnostic challenge. We aimed to study the clinical, radiological, and pathological features and behavior of hybrid odontogenic lesions, to enhance awareness about these rare lesions., Method: Hematoxylin and Eosin slides of hybrid odontogenic lesions diagnosed between January 01, 2012 and December 31, 2020, were reviewed. Demographic and radiological information were obtained from the patient's medical records., Results: 8 cases were diagnosed with a mean age of 19.1 years and male to female ratio of 1:1.7. Involvement of mandible was more common (n = 5) as compared to maxilla (n = 3). All patients presented with swelling for an average of 9.75 months (3-25 months) duration. Bleeding, loose teeth, pain and facial asymmetry were reported in 5,3, 3, and 2 cases, respectively. Radiologically, 7 cases were well demarcated, 75% cases (n = 6) were radiolucent, and average radiological size was 4.8 cm. All patients were managed with surgery alone. 5 cases (62.5%) underwent enucleation and curettage, while local excision, en-block resection and segmental mandibulectomy were performed in 1 case each. Histologically, ossifying fibroma/cemento-ossifyiong fibroma were the most lesion, occurring in 5 cases (62%), followed by giant cell granuloma like lesions (GCG) i.e., central and peripheral giant cell granuloma (n = 3), Adenomatoid Odontogenic tumor (AOT) (n = 2), and DC (n = 2), ameloblastic fibroma (AF) (n = 1), Ameloblastoma (n = 1), calcifying odontogenic cyst (COC) (n = 1), and complex odontoma (n = 1). No evidence of recurrence was noted after 4-99 months of surgery (mean: 32.9) in cases with available data (n = 7). Long-term complaints included facial asymmetry (n = 2) and pain (n = 1)., Conclusion: Most hybrid odontogenic lesions affect young females in the second decade of life and commonly show COF and OF as hybrid components. A conservative approach to management appears adequate., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

This article aimed to collectively present the demographic, clinical, radiographic and histopathological features as well as the treatment performed along with its outcome for all the cases of adenoid ameloblastoma with dentinoid (AAD) reported in scientific literature till date. Ameloblastoma and adenomatoid odontogenic tumours are the most common odontogenic neoplasms. However, AAD, a hybrid variant of the two lesions, is found to be extremely rare. The lesion comprises of characteristic histopathological features of ameloblastoma and adenomatoid odontogenic tumour and shares certain clinical characteristics with either of the entities. AAD may be considered to be present at the more aggressive end of spectrum of benign odontogenic neoplasms. Owing to the frequent tendency of the lesions to be underdiagnosed, careful histopathological screening of submitted biopsies is warranted. With the increase in number of reported cases in the recent years, it is likely to be included as a separate entity in the upcoming World Health Organization classification., (© Copyright 2022, Sultan Qaboos University Medical Journal, All Rights Reserved.)

Introduction and Importance: An adenomatoid odontogenic tumor is a rare medical condition. Large tumor (or several) often appears in the maxillae. In a minority of cases, the tumor(s) appear in the mandible., Case Presentation: We report on a case of a 24-year-old female diagnosed with a mandibular adenomatoid odontogenic tumor, a giant tumor measuring approximately 22 × 25 × 17 cm. The tumor was located on the side of the mandible, causing facial deformity, malnutrition, and hemorrhaging. We assessed the patient's overall condition, carried out a resection of the tumor and mandible from the right condyle to the left mandibular angle, and reconstructed the mandibular defect with a fibula free flap. After the treatment, the patient was followed up for 1 year, with no recurrence detected over this period., Clinical Discussion: Because adenomatoid odontogenic tumors are benign odontogenic lesions, which are painless and slow-growing, most are surgically removed or treated conservatively. However, the above treatment measures cannot be applied in the case of a giant tumor that causes facial deformity, destroys the entire jawbone, and has complications such as hemorrhaging and malnutrition. After the tumor resection, the defect is still significant. Accordingly, reconstruction using a microsurgical bone flap is an effective method instead., Conclusion: Large adenomatoid odontogenic tumors in the mandible are rare, and treatment cannot follow conventional methods. Accordingly, defect reconstruction after tumor resection is essential., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: Calcifying odontogenic cysts (COC) and adenomatoid odontogenic tumors (AOT) have similar radiographic findings. We examined the radiographic and computed tomography (CT) images of patients histologically diagnosed with COC or AOT and identified their characteristic findings., Methods: The subjects included 12 patients histologically diagnosed with COC or AOT (one female and five males per group), who underwent CT at our hospital between Nov 1998 and Jun 2019. The location of the lesion, impacted tooth, bone expansion, root resorption, tooth migration, calcified body, and presence or absence of a high-intensity zone in the marginal area of the lesion were examined., Results: In patients with COC, five patients with COC exhibited bone expansion toward the buccal side. The lesion encompassing the crown was attached to the cement-enamel junction and contained a radiopaque lesion with a calcified body. In 6 patients with COC, irregularly shaped calcified bodies were observed with small tooth-like structures. In patients with AOT, all six patients with AOT exhibited bone expansion toward the buccal and lingual sides. The lesion encompasses a part of the tooth root or the entire tooth. Punctate calcification was observed within the lesion and the marginal area in three patients, and a high-intensity zone was observed in the marginal area of the lesion in two patients., Conclusion: We report imaging findings that may be characteristic of COC and AOT, suggesting that CT findings may be useful for differentiating between COC and AOT., (© 2021. The Author(s), under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd.)

Objective: Integrins function to bind cells to extracellular matrix in tissues, which triggers downstream signaling cascades that are important in cell survival, proliferation, cytokine activation, and cytoskeleton reorganization. These processes also play significant roles in neoplasms. This work aimed to investigate the pattern of expression of FAK, paxillin, and PI3K in ameloblastoma and adenomatoid odontogenic tumor (AOT)., Materials and Methods: Immunohistochemistry was used to study FAK, paxillin, and PI3K in 45 ameloblastomas (32 conventional, 12 unicystic, and 1 peripheral types), 7 AOTs, and two developing human teeth., Results: Weak expression of FAK was seen in all AOT cases, while ameloblastoma had varying expression patterns, mostly strong to weak. The pattern of expression of paxillin and PI3K was relatively similar in both tumor types. In the dental germ, FAK and paxillin stained all the enamel organ components, while PI3K stained strongly the inner enamel epithelium. Stromal expression of FAK was not found to be useful in differentiating between tumors or tumor classes., Conclusion: The expression of the proteins in the enamel organ suggests that their signaling may be important in odontogenesis. While some ameloblastomas strongly expressed FAK, all cases of AOT had weak signals suggesting low presence and phosphorylating activity of FAK in the latter., Clinical Relevance: A subset of FAK-positive ameloblastoma (as well as their malignant or metastasizing counterparts) which may have relatively aggressive behavior may be candidates for drug targeting of FAK as an additional management option.

Claudins are integral to the structure and function of tight junctions. Altered claudin expression has been shown to affect disease behavior and patient prognosis in various neoplasms. The objectives of this study were to analyze the claudin-1, -4 and -7 expression in odontogenic tumors and characterize their expression pattern in distinct tumor cell types in relation to the recurrence potential. Sixty-nine cases of odontogenic tumors, including 43 ameloblastomas (AM), 17 adenomatoid odontogenic tumors (AOT), 6 ameloblastic fibromas (AF) and 3 ameloblastic carcinomas (AC) were investigated for claudin-1, -4 and -7 expression immunohistochemically. The staining was analyzed semi-quantitatively and categorized into 4 levels, based on the percentage of positively stained neoplastic epithelial cells. Claudin-1 was expressed in all AOT and AF cases, whereas most AC (66.7%) showed no expression. The claudin-1 staining was moderate-to-intense in the odontogenic epithelium of AF. In contrast, its staining of ameloblast-like cells and stellate reticulum-like cells in AM was weak. Claudin-7 expression was noted in all tumor types studied, while the expression of claudin-4 was limited and mainly localized in the squamous differentiated cells of AM and AC. AM showed significantly higher claudin-4, but lower claudin-7 expression than AOT. In addition, AC showed diminished claudin-1 immunoreactivity, compared to AOT. Low claudin-1 expression in AM was significantly associated with the increased clinical recurrence. The loss of claudin-1 may underlie the locally invasive nature of AM.

Background: Limited statistically and clinically significant studies have been down on connective tissue factors in the odontogenic tumors. Therefore, the aim of this study was to determine the biological behavior of two selected epithelial odontogenic tumors (Ameloblastoma and Adenomatoid odontogenic tumor) by detecting CD34, VEGFR3 and eosinophil densities., Methods: In this cross-sectional study, paraffin blocks including 20 cases of ameloblastoma and 20 (AOT), were selected. Totally, 4 sections were prepared for hematoxylin-eosin, Congo red staining, immunohistochemistry with CD34 and VEGFR3. Expression of VEGFR3, CD34 and lymphatic, blood vessels and eosinophil densities was examined., Results: The mean of blood, lymphatic vessels and eosinophils densities in ameloblastoma were 14.9 ± 6.4, 4.4 ± 2 and 3.2 ± 2.7, respectively; and in AOT, they were 8.9 ± 3.4, 3.6 ± 1.3 and 1.2 ± 07, respectively. There was a significant difference in eosinophils and blood vessels densities between the two lesions (p = 0.005; p = 0.003). By increasing the density of eosinophils, the density of the blood vessels increased in both lesions (r = 0.539, P = 0.001) There was no positive relationship between eosinophils and lymphatic vessels densities in the two above mentioned odontogenic lesions (p = 0.288, R = 0.191)., Conclusion: It can be suggested that tumor angiogenesis and eosinophil densities may play a more effective role than lymphangiogenesis in local invasive behavior of ameloblastoma rather than AOT., Competing Interests: The authors have none to declare., (© 2019 Published by Elsevier B.V. on behalf of Craniofacial Research Foundation.)

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., Competing Interests: The authors declare no conflict of interest.

Purpose: To investigate the contribution of MMP-13 in tumor aggressiveness, by acting on the reorganization of the extracellular matrix, regulating the biological activity of cytokines in odontogenic epithelial lesions, as well as to evaluate the role of EMMPRIN as an inducer of MMP-13., Methods: Twenty solid ameloblastomas (SAs), 10 unicystic ameloblastomas (UAs), 20 odontogenic keratocysts (OKCs), and 20 adenomatoid odontogenic tumors (OATs) were selected. The expression of MMP-13 and EMMPRIN was evaluated in epithelial/connective tissue by determining the score of immunoreactive cells., Results: Higher concentration of MMP-13 was observed in epithelium of SAs and OKCs (p = 0.316), while in connective, MMP-13 was more expressed in OKCs and UAs (p = 0.213). OKCs exhibited the highest immunoreactivity score for EMMPRIN in the epithelium (p = 0.091). In connective tissue, a larger number of immunoreactive cells were observed in OKCs and UACs (p = 0.357). There was a moderate correlation (r = 0.343/p = 0.004) between MMP-13/EMMPRIN in epithelium and strong correlation (r = 0.474/p < 0.001) in connective tissue., Conclusion: We suggest that the OKCs, SAs and UAs presented greater immunoexpression for MMP-13 and EMMPRIN, since they were lesions of more aggressive behavior, with smaller expressions in the AOTs that are admittedly indolent. However, we did not find a statistically significant difference between the expression of MMP-13 and EMMPRIN in lesions studied. The positive correlation found between MMP-13 and EMMPRIN in the epithelial and connective tissue of odontogenic lesions analyzed, seems to be related to the role of EMMPRIN as an inducer of MMP-13 expression.

Odontogenic tumors are rare entities, often derived from the epithelial remnants in the gnathic bones following odontogenesis. This brief manuscript will seek to address recent developments pertaining to odontogenic tumors as well as particularly uncommon odontogenic tumors and the difficulties in their diagnosis.

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.

Ameloblastoma and adenomatoid odontogenic tumor (AOT) are jaw tumors derived from the teeth forming apparatus. While ameloblastoma is a destructive, debilitating lesion, with conventional surgical treatment leading to facial deformity and morbodities, AOT shows indolent clinical behavior. The underlying molecular mechanisms associated with their biological behavior are unknown. The use of high-density whole-genome microarray analysis in ameloblastomas and AOT revealed high frequency of genomic gain at 14q32.33, which encompasses the long noncoding RNA (lncRNA) gene KIAA0125. In the present study, we aimed to investigate the expression profile of KIAA0125 in these tumors. Thirteen samples were included (five solid/multicystic ameloblastomas, four AOT, and four dental follicles). The relative quantification of KIAA0125 expression was obtained by qPCR and interactions of KIAA0125 were in silico predicted. We detected higher levels of KIAA0125 transcripts in the ameloblastoma group compared to dental follicles (p = 0.042). The expression levels of KIAA0125 in AOT were not different from that of dental follicles. KIAA0125 was predicted to interact with 41 miRNA families. Four miRNAs of these families have been previously reported differentially expressed in ameloblastoma, being miR-135a-5p, miR-204-5p and miR-205-5p upregulated, and miR-150-5p downregulated. The lncRNA KIAA0125 is likely involved in the ameloblastoma pathobiology. LncRNAs hold strong promise as therapeutic targets and experimental validation of this lncRNA functions may lead to tailored therapies targeting KIAA0125 in extensive and recurrent ameloblastoma cases., (Copyright © 2018. Published by Elsevier GmbH.)

Objective: This study aimed to assess the frequency of KRAS mutation and its association with the presence of the MAPK/ERK signaling pathway proteins in adenomatoid odontogenic tumors., Study Design: Paraffin-embedded tissue samples from nine cases of adenomatoid odontogenic tumor were used. Genomic DNA was extracted from each sample; in one case, genetic mutations in 50 cancer-associated genes were examined by next-generation sequencing. Hotspot mutations in the RAS family were analyzed by Luminex assay using the remaining eight cases. Subsequently, immunohistochemistry for KRAS, CRAF, BRAF, EGFR, ERK, MEK, and BRAFV600E was performed., Results: A KRAS G12D missense mutation was detected in the DNA sequence of the tumor cells, but it was not detected in the stromal tissue. KRAS G12V and KRAS G12R mutations were detected in two and four cases, respectively. For immunohistochemistry, all the cases were EGFR, KRAS, BRAF, CRAF positive, one case was ERK negative,and one case was MEK and ERK negative, all the other remaining cases were MEK and ERK positive., Conclusion: KRAS mutation at codon 12 and the presence of MAPK/ERK pathway proteins were detected suggesting their association with tumorigenesis of adenomatoid odontogenic tumors., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.)

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., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Context: This retrospective study was planned to ascertain the relative frequency of odontogenic tumors (OTs) in an Indian population in the light of the latest World Health Organization (WHO) classification., Aim: To compare data with various reports from other parts of the world., Study Design: Retrospective study., Materials and Methods: The histopathology records and archived slides of all lesions diagnosed as "OT" in the Department of Oral Pathology and Microbiology of Government Dental teaching institute, Mumbai, Maharashtra, India, were recovered from the period January 1981-December 2016. A total of 250 lesions thus classified were reviewed for age, gender, site of tumor, and histopathologic typing. The tumors were reclassified according to the WHO 2017 criteria., Statistical Analysis: Microsoft Excel 2010 was used for statistical analysis., Results: In all, 250 cases of OTs were reported in a 35-year period. OTs in this study constituted 7.14% of all the 6797 registered biopsies. The most frequent histological type was ameloblastoma (AML) (30.8%), followed by odontoma (19.2%), unicystic ameloblastoma (18.4%), adenomatoid OT (14%), cementifying fibroma (6%), odontogenic myxoma and cementoblastoma (2.4% each), calcifying epithelial OT and odontogenic fibroma (2% each), ameloblastic fibroma (1.2%), squamous OT, dentinogenic ghost cell tumor, peripheral ameloblastoma, ameloblastic carcinoma and ameloblastic fibrosarcoma (odontogenic sarcoma) (0.4% each)., Conclusion: A frequency of 7.14% of OTs was observed in this study. AML comprised the single most common tumor of all OTs. This study observed geographic variations in the frequency and distribution of OTs., Competing Interests: None

Adenomatoid odontogenic tumor (AOT) is always benign. Given the very rare recurrence rate and the zero potential of malignant transformation, authors have considered it a hamartoma. Accordingly, 'AOT' is no more than a misnomer. This report, however, describes the first recognition of cellular atypia and plemorphism in a peripheral orophayrngeal AOT which embraces an ameloblastic component. The overall picture was diagnosed, after careful histological and immunohitochemical assessment, as a peripheral adenoid ameloblastoma. This find may promote a new pathogenetic scenario to the nosology of this debatable lesion., (© Copyright Società Italiana di Anatomia Patologica e Citopatologia Diagnostica, Divisione Italiana della International Academy of Pathology.)

Adenomatoid odontogenic tumor (AOT) is a benign epithelial odontogenic tumor characterized by slow and progressive growth. When central lesions are associated with an unerupted permanent tooth, they are also known as the follicular type. Histological variants of AOT may complicate diagnosis with possible adverse effects on treatment and prognosis. The aim of this study is to report a case of a follicular AOT with extensive calcifying epithelial odontogenic tumor (CEOT)-like histopathological areas in the anterior region of the mandible that was treated by enucleation. The teeth displaced by the tumor were repositioned with orthodontic treatment, and after 7 years of follow-up, the bone trabeculae were normal with no evidence of recurrence. The clinical, radiographic and histopathologic aspects of these tumors are discussed and the debate surrounding whether these cases are true combined lesions or histologic variants of the primary tumor is raised.

This study was focused on the immunohistochemical profile of the adenomatoid odontogenic tumor. A Pub/Medline search revealed a number of immunohistochemical studies including cytokeratin profiles, extracellular matrix proteins, Integrins, ameloblast-associated proteins resorption regulators (RANK, RANKL), p53, PCNA, MDM2 protein, cyclin D1, Ki-67, Bcl-2 metallothionein, metalloproteinases, D56 hepatocyte growth factor, c-met, DNA methyltransferase, podoplanin, TGF-βI, Smad-2/3, Smad-I-5/-8, Smad 4, beta- catenin, calretinin, and clonality. Careful interpretation of the findings indicates that the adenomatoid odontogenic tumor may be more of a hamartomatous than neoplastic nature., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aim: To investigate the presence of myofibroblasts (MFBs) in epithelial odontogenic lesions by immunohistochemistry and to correlate the findings with tumor aggressiveness, as well as to analyze the expression of TGF-β1 and IFN-γ during the differentiation of these cells., Methods and Results: Twenty solid ameloblastomas (SAs), 10 unicystic ameloblastomas (UAs), 20 keratocystic odontogenic tumors (KCOTs), and 20 adenomatoid odontogenic tumors (AOTs) were selected. For evaluation of the presence of MFBs, anti-α-SMA-immunoreactive cells were quantified in connective tissue near the epithelium. The expression of TGF-β1 and IFN-γ was evaluated in epithelial and connective tissue by determining the percentage of immunoreactive cells. A higher concentration of MFBs was observed in SAs (mean of 30.55), followed by KCOTs (22.50), UAs (20.80), and AOTs (19.15) (P = 0.001). There was no significant correlation between the immunoexpression of TGF-β1 or IFN-γ and the number of MFBs (P > 0.05)., Conclusions: The larger number of MFBs suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these lesions. The lack of correlation between the number of MFBs and immunoexpression of TGF-β1 and IFN-γ indicates that these proteins are not involved in the differentiation of this type of contractile cell in the lesions studied and that only the use of immunohistochemistry to establish such a correlation is a limiting factor., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: Since its recognition as a physiologic process associated with tumor, among molecular mechanisms involved in tumor progression, defects in regulation of apoptosis have generated an accelerating volume of research that has sought to elucidate the role of programed cell death in pathogenesis and treatment of various tumors. Therefore, this study was performed to understand better the diverse biological profile of epithelial odontogenic tumors with the help of immunohistochemical expression of Bcl-X protein., Materials and Methods: We studied Bcl-X protein expression in 45 cases of epithelial odontogenic tumors which included 15 cases each of ameloblastomas, keratocystic odontogenic tumor (KCOT) and adenomatoid odontogenic tumor (AOT) and correlated the expression with their growth pattern., Results: Cytoplasmic staining of Bcl-X revealed overexpression in ameloblastoma when compared to KCOT and AOT. Percentage of positive cells showed a statistically significant difference, P = 0.007 between ameloblastoma and KCOT, whereas P < 0.001 between ameloblastoma and AOT. However, no significance was observed between KCOT and AOT ( P = 0.132)., Conclusion: The present study supports the fact that epithelial odontogenic tumors show diverse growth profiles. An increased Bcl-X expression was seen in ameloblastoma compared to KCOT and least expression in case of AOT which could be indicative of more aggressive biological behavior and increased cell survival activity of ameloblastoma than KCOT and AOT. This signifies the diagnostic relevance of this biomarker and also could be a possible regulator of the proliferative compartment by contributing in tumor progression and cytodifferentiation of epithelial odontogenic tumors., Competing Interests: There are no conflicts of interest.

Objectives: The present study evaluated the immunohistochemical expression of BMP-2 and BMP-4 and of their receptors (BMPR-IA and BMPR-II) in solid ameloblastoma (SA), unicystic ameloblastoma (UA) and adenomatoid odontogenic tumor (AOT) in order to obtain a better understanding of their role in the development and biological behavior of these tumors., Design: This study analyzed these proteins in 30 cases of SA, 10 cases of UA, and 30 cases of AOT. Immunoexpression was evaluated in the parenchyma and stroma by attributing the following scores: 0, no stained cells; 1, ≤10%; 2, >10% and ≤25%; 3, >25% and ≤50%; 4, >50% and ≤75%.; 5, >75% stained cells., Results: In SAs, positive correlations were observed between the stromal and parenchymal expression of BMP-2 (p<0.001) and between the stromal expression of BMP-2 and BMP-4 (p=0.020), as well as between the stromal expression of BMPR-II and BMP-4 (p=0.001) and the stromal and parenchymal expression of BMPR-II (p<0.001). In UAs, correlations were detected between the stromal and parenchymal expression of BMP-4 (p=0.035) and between the stromal expression of BMP-4 and BMPR-IA (p=0.022). In AOTs, analysis of immunoexpression in the parenchyma revealed positive correlations between all proteins., Conclusion: BMPs and their receptors play an important role in the differentiation and development of ameloblastomas and AOTs, but may not explain the different biological behaviors of these lesions. The positive correlation observed in AOTs might be related to the formation of mineralized material in this tumor., (Copyright © 2016 Elsevier Ltd. All rights reserved.)