Odontogenic tumors: where are we in 2017 ?

Bcl-2 and galectin-3 expression is associated with recurrence of ameloblastoma

Background

Ameloblastoma is a benign odontogenic neoplasm with a high recurrence rate. Identifying cellular and molecular changes in this neoplasm may help predict the recurrence risk. Bcl-2 and galectin-3 are anti-apoptotic proteins associated with the prognosis of many neoplasms. However, there are a few studies focusing on the association between these two markers and recurrence of ameloblastoma. This study aimed to investigate the association of Bcl-2 plus galectin-3 expression and recurrence of ameloblastoma.

Materials and Methods

This retrospective cross-sectional study was designed on 48 paraffin-embedded blocks diagnosed as ameloblastoma from 1998 to 2019. We retrieved follow-up data from patients' records and used immunohistochemical staining for Bcl-2 and galectin-3 antibodies. Then, we analyzed their association with recurrence using Chi-square and Mann-Whitney test as well as recurrence-free survival using Kaplan-Meier curves and linear Cox regression. The level of statistical significance was P < 0.05.

Results

Twenty-six patients had experienced the recurrence. The mean follow-up time was 93.53 months. There was a significant association between Bcl-2 plus cytoplasmic galectin-3 staining and recurrence (both P < 0.001). Furthermore, in univariate analysis, high expression of Bcl-2 was associated with less recurrence-free survival (log-rank: P = 0.020-univariable Cox: P = 0.033), but in multiple Cox regression, there was no significant association (P = 0.471). High cytoplasmic galectin-3 expression was also associated with less recurrence-free survival (log-rank: P = 0.007-univariable Cox: P = 0.015-multiple Cox: P = 0.044). Furthermore, we found a correlation between Bcl-2 and cytoplasmic galectin-3 staining (P = 0.001).

Conclusion

It seems that Bcl-2 and cytoplasmic galectin-3 staining might predict the risk of ameloblastoma recurrence. However, only the cytoplasmic galectin-3 staining might be an independent predictor of ameloblastoma recurrence, and we recommend further studies.

Clinicopathological and molecular insights into odontogenic tumors associated with syndromes: A comprehensive review

The association between genetic syndromes and odontogenic tumors encompasses several entities, reflecting the intricate interplay between genetic factors and the development of these lesions. The present study aimed to comprehensively investigate the associations between genetic syndromes and odontogenic tumors. We delineated the diverse spectrum of syndromic connections, including key syndromes such as Gardner syndrome, Gorlin syndrome, Schimmelpenning syndrome, and others. Our findings underscore the clinical significance of recognizing odontogenic tumors associated with genetic syndromes as diagnostic indicators for early intervention. We advocate for multidisciplinary collaboration among clinicians, geneticists, and researchers to deepen our understanding of the underlying mechanisms driving these syndromic associations. In light of this, our study contributes to the growing body of knowledge in dentistry and medical genetics, offering insights that may inform clinical practice and enhance patient care for individuals affected by genetic syndromes and odontogenic tumors.

Odontogenic carcinosarcoma of the mandible: A case report

Key Clinical Message

Odontogenic carcinosarcoma, a rare and challenging diagnosis, was identified in a 60-year-old male through histopathology, revealing a biphasic neoplasm with malignant epithelial and mesenchymal components. Surgical resection is crucial for management, highlighting the importance of vigilant postoperative follow-up to ensure early detection of any recurrence.

Abstract

One rare mixed malignant odontogenic tumor is odontogenic carcinosarcoma, which comprises malignant epithelial and mesenchymal components. Diagnosing odontogenic carcinosarcoma is challenging due to its rarity and atypical clinical presentation. This study reports a 60-year-old male patient who presented with a painless swelling on the right side of his face and experienced facial asymmetry for 6 months, ultimately diagnosed with odontogenic carcinosarcoma. A biphasic neoplasm with malignant alterations in both epithelial and mesenchymal components was identified upon histopathological examination. MRI imaging showed an expansile multilobulated lytic lesion with cortical erosion and extraosseous extension in the posterior region of the right mandibular body and ramus. Following contrast administration, homogeneous lesion enhancement was observed, with a few small non-enhancing necrotic areas in central parts. The patient subsequently underwent a right hemi-mandibulectomy with resection of adjacent soft tissues and neck dissection due to lymph node involvement. The resulting defect was reconstructed using a pectoralis major flap. No recurrence or metastasis was reported during the 6-month follow-up, reinforcing the positive results. This case highlights the importance of recognizing odontogenic carcinosarcoma and underscores the challenges in diagnosing and managing this rare tumor. Early identification and aggressive treatment can lead to positive outcomes, as evidenced by the absence of recurrence or metastasis in this patient during the follow-up period.

Aggressive presentation of ameloblastic fibro-odontoma: a clinical-pathological enigma

Ameloblastic fibro-odontoma (AFO) is a rare, gnathic, benign, mixed odontogenic tumor that commonly presents in the first or second decade of life as a unilocular and rarely multilocular radiolucency with variable amounts of calcified material. Tumor progression is typically indolent, and generally accepted treatment is surgical enucleation and curettage. This case report describes an atypical presentation in a 14-year-old male with a multilocular, aggressive AFO requiring hemimandibulectomy with immediate osseous and dental "Jaw-in-a-Day" reconstruction. This report highlights the debate regarding whether AFO is a true neoplasm or an early-stage hamartoma in the continuum of complex odontoma formation. Regardless of the pathogenesis, maxillofacial surgeons and pathologists should be cognizant of the potential for AFO to develop locally aggressive behavior with considerable morbidity.

Differential Expression of Immunohistochemical Markers in Ameloblastoma & Ameloblastic Carcinoma: A Systematic Review and Meta-analysis of observational studies

Background

Differentiating between ameloblastoma (AB) and ameloblastic carcinoma (AC) is difficult, especially when AB has atypical cytological characteristics or an uncommon clinical history. This systematic review and meta-analysis aimed to elucidate the differential expression of immunohistochemical markers between AB and AC.

Methods

We conducted a thorough search of PUBMED and SCOPUS according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify cross-sectional studies that compared the expression of immunohistochemical markers in AB and AC. We used a random-effects model to analyze the risk ratios and their corresponding 95% confidence intervals (CIs). The quality of the included studies was assessed using the Newcastle-Ottawa scale. The Egger's test was used to assess publication bias.

Results

In total, 301 articles were identified. After excluding irrelevant titles and abstracts, 86 articles were selected for full-text review. We categorized the 41 markers into proliferative and non-proliferative markers. Among non-proliferative markers, nuclear markers were differentially expressed in AB and AC. SOX2 was the only marker that significantly differentiated AB and AC, with an RR of -0.19 (CI 0.10-0.36, I2=0).

Conclusion

The current evidence suggests the significance of SOX2 in differentiating between AB and AC, warranting prospective confirmation in well-defined extensive studies. We highlight the paucity of high-quality replicated studies of other markers in this field. Collaborative efforts with standardized techniques are necessary to generate clinically useful immunohistochemical markers.

Identification of Molecular Mechanisms of Ameloblastoma and Drug Repositioning by Integration of Bioinformatics Analysis and Molecular Docking Simulation

Background

Ameloblastoma (AM) is a benign tumor locally originated from odontogenic epithelium that is commonly found in the jaw. This tumor makes aggressive invasions and has a high recurrence rate. This study aimed to investigate the differentially expressed genes (DEGs), biological function alterations, disease targets, and existing drugs for AM using bioinformatics analysis.

Methods

The data set of AM was retrieved from the GEO database (GSE132474) and identified the DEGs using bioinformatics analysis. The biological alteration analysis was applied to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Protein-protein interaction (PPI) network analysis and hub gene identification were screened through NetworkAnalyst. The transcription factor-protein network was constructed via OmicsNet. We also identified candidate compounds from L1000CDS2 database. The target of AM and candidate compounds were verified using docking simulation.

Results

Totally, 611 DEGs were identified. The biological function enrichment analysis revealed glycosaminoglycan and GABA (γ-aminobutyric acid) signaling were most significantly up-regulated and down-regulated in AM, respectively. Subsequently, hub genes and transcription factors were screened via the network and showed FOS protein was found in both networks. Furthermore, we evaluated FOS protein to be a therapeutic target in AMs. Candidate compounds were screened and verified using docking simulation. Tanespimycin showed the greatest affinity binding value to bind FOS protein.

Conclusions

This study presented the underlying molecular mechanisms of disease pathogenesis, biological alteration, and important pathways of AMs and provided a candidate compound, Tanespimycin, targeting FOS protein for the treatment of AMs.

Peripheral Dentinogenic Ghost Cell Tumor- Diagnostic Challenge in a Gingival Epulis: Report of a Case with Update of all Dentinogenic Ghost Cell Cases Reported in English Literature

Dentinogenic ghost cell tumor (DGCT), a variant of the calcifying odontogenic cyst, is considered to be a benign epithelial and mesenchymal neoplasm containing aberrant epithelial keratinization, ghost cells, and spherical calcifications. While there can be peripheral and central variants of this entity, the extraosseous type is rarer and usually innocuous in its clinical presentation. The aim of this article is to report a case of peripheral DGCT on the maxillary anterior region in a 14-year-old female evolving for 5 years and to emphasize the importance of histopathologic examination of gingival growths to avoid diagnostic pitfalls. A compilation of all reported cases in the English literature till date with details on the site, size, age sex, symptoms radiographic features, treatment follow-up, and recurrences has been attempted for better understanding of the biologic nature of this rare neoplasm.

Immunohistochemical Expression of Ki-67 and p53 and Their Prognostic Role in Ameloblastoma: A Longitudinal Study

Objectives

Ameloblastoma, comprising approximately 11% of all odontogenic tumors, is a locally aggressive tumor with a high recurrence rate. This study aimed to assess the immunohistochemical expression of Ki-67 and p53 and their association with clinical and pathological factors among patients with ameloblastoma.

Methods

Retrospective follow-up data of patients histologically confirmed with ameloblastoma at Makerere College of Health Sciences in Kampala, Uganda from January 2012 to December 2018 were retrieved. Factors associated with Ki-67 and p53 immunohistochemical expression were determined using one-way one-way analysis of variance. Chi-square and Fisher's exact statistical tests were used to assess factors associated with recurrence. A two-tailed p < 0.05 was considered statistically significant.

Results

A total of 40 patients confirmed histologically with ameloblastoma were included in the analysis. The majority (62.5%) of cases were of the conventional type of ameloblastoma. The expressions of Ki-67 and p53 were 52.5% and 85.0%, respectively. Recurrence was found in 47.5% of patients and it was associated with conventional histological type (p=0.042), segmental resection (p < 0.001), tumor size (p < 0.001), and high p53 expression (p=0.041).

Conclusions

Almost half the cases in this study had recurrence. The immunohistochemical expression of p53 was significantly higher than that of Ki-67.

Peripheral Odontogenic Myxoma of Zygoma and Orbital Region - A Unique Case Report with Review of Literature

Rationale

Peripheral odontogenic myxoma (POM) is a rare mesenchymal tumour and it is the first case report of POM involving orbital and zygoma region.

Patient Concerns

A 16-year-old male presented with a painless, slow-growing swelling over his left infratemporal region.

Diagnosis

The histopathological examination of the tumour was diagnosed as POM.

Treatment

The patient was treated by surgical removal of tumour under general anaesthesia.

Outcomes

The patient has been under follow-up for the past 2.5 years and there has been no recurrence.

Take-away Lessons

POM is a rare mesenchymal tumour. To our knowledge, this is only the second report of a POM of the infratemporal region and the first report of a myxoma, which extends into the zygomatic region and lateral wall of the orbit.

A massive dentinogenic ghost cell tumor that crossed the midline: A rare case report

Dentinogenic ghost cell tumor (DGCT) is a rare tumor of odontogenic origin. A locally invasive lesion can be described by the presence of ameloblast-like epithelial islands, ghost cells, and dentinoid material. It is one of the few lesions with a predilection for the Asian population. The available literature has revealed that only 131 cases to date have been reported and published from 1968 to 2022. The following is a case report of a 25-year-old male with a tumor in the left lower back teeth region for the past 1 month. Orthopantomogram (OPG) reveals a well-defined unilocular radiolucency extending anteroposteriorly and crossing the midline. Histopathology revealed basal ameloblast-like cells and central stellate reticulum-like cells with the characteristic presence of ghost cells. The diagnosis was made based on the clinical, radiographical, and histopathological correlation and was confirmed using immunohistochemical analysis as a DGCT.

BRAF inhibitors in BRAF V600E-mutated ameloblastoma: systematic review of rare cases in the literature

BACKGROUND

Ameloblastoma in 66% of the cases harbor a somatic mutation of the "mitogen-activated protein kinase" signaling pathway (BRAF V600E). In V600E mutations, BRAF is in the permanent "on" state and relays the growth-promoting signals independently of the EGFR pathway. Therefore, mutant BRAF represents a target for handful of new drugs.

METHODS

We conducted a literature search, with the search terms "Vemurafenib, Dabrafenib, Ameloblastoma, and BRAF." These included seven case reports with nine patients who underwent monotherapy with Dabrafenib or Vemurafenib or combination therapy with Dabrafenib and Trametinib.

RESULTS

The patients age ranges from 10 years up to 86 years. The distribution of women and men is 4:5. Patients with an initial diagnosis of ameloblastoma, as well as recurrences or metastasized ameloblastoma were treated. Indications cover neoadjuvant therapy up to the use in metastasized patients in an irresectable state. Results ranging from "only" tumor size reduction to restitutio ad integrum.

CONCLUSION

We see the use of BRAF Inhibitors to reduce tumor size with consecutive surgical treatment as a reasonable option for therapy. However, we are aware that at present the data are based only on case reports with the longest follow-up of just 38 months. We encourage further clinical trials in the use of BRAF Inhibitors for selecting ameloblastoma patients in a multi-center setting.

Ameloblastic Fibrosarcoma of the Jaw: Case Report, Genetic Profiling, and Literature Review

Ameloblastic fibrosarcoma (AFS) is considered a malignant progression resulting from dysplastic changes in an ameloblastic fibroma (AF). Both tumors are extremely rare, with only a few cases reported in the scientific literature. Notably, BRAF mutations have been identified in ameloblastomas, suggesting a connection between ameloblastic morphology and BRAF mutations, as AF is believed to be the precursor neoplasm leading to AFS. In this study, we present a case of AFS in a 25-year-old male. The tumor tissue underwent molecular analysis, specifically next-generation sequencing (NGS) using the Oncomine Comprehensive Assay v3 System. The analysis revealed pathogenic mutations in TP53 and RB genes, as well as copy number gains in NTRK1, MDM4, and BRAF. Additionally, we provide a summary of the literature's findings from the analysis of 107 previously reported AFS cases. Our findings suggest the existence of a molecularly distinct subtype, emphasizing the importance of comprehensive molecular testing for these patients.

Hybrid Ameloblastoma Arising from a Treated Odontogenic Keratocyst of the Mandible: A Case Report With Literature Review

Odontogenic Keratocyst (OKC) is an odontogenic cyst of developmental origin arising from remnants of the dental lamina. Malignant or benign transformations though rare have been noticed from their epithelium. Ameloblastomatous transformation from an OKC is extremely rare with such lesions being referred to as combined/"hybrid" odontogenic lesions. In this article, we present an intriguing case of a 60-year-old male who was operated on for OKC of the anterior mandible 3 years before, who came back with a complaint of swelling over the same site. Incisional biopsy revealed the acanthomatous type of ameloblastoma for which segmental resection with immediate reconstruction using recon plate was done. Excision biopsy revealed a plexiform variant as well, thus exhibiting a hybrid pattern. Surgeons should be aware of this hybrid presentation of ameloblastoma arising from the epithelium of OKC as the acanthomatous subtype is known for its notorious genetic behavior leading to recurrence and aggressive nature of this tumor.

Computer-guided buccal cortical plate separation for removal of calcified benign odontogenic tumors affecting the mandibular angle region

PURPOSE

Surgical removal of intra-bony calcific benign lesions is technically challenging regarding its accessibility, proximity to vital structures, and deteriorating effect on the remaining bony structures.

METHODS

Computer-guided buccal cortical plate separation was performed for ten patients using patient-specific osteotomy locating guides and pre-bent plates. The guide was designed to outline the osteotomy, the buccal cortical plate was separated, the lesion was removed, and finally, the pre-bent plates were used to fix the separated cortex.

RESULTS

Surgical procedures were uneventful for all patients, operation time was 39.5 ± 13.01 min, postoperative pain decreased within the follow-up time intervals, and there was a statistical significant difference between the time intervals (P value < 0.001). Edema and trismus were acceptable. One case showed nerve affection which resolved after 4 weeks.

CONCLUSION

Computer-guided buccal cortical plate separation for removal of intra-bony calcified benign lesions provides a promising approach, especially for inexperienced surgeons.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05329974 . Registered on 6 April 2022-retrospectively registered.

Ameloblastoma: An Updated Narrative Review of an Enigmatic Tumor

Ameloblastoma is one of the most common benign odontogenic tumors of the jaw that constitutes about 10% of all tumors that arise in the mandible and maxilla. It is a slow-growing but locally invasive tumor that presents with painless swelling of the mandible or maxilla. The World Health Organization (WHO) classification of 2017 describes ameloblastomas of the following four types: ameloblastoma; unicystic ameloblastoma; extraosseous/peripheral ameloblastoma; and metastasizing ameloblastoma. The diagnosis of ameloblastoma requires computerized tomography (CT) imaging as well as a biopsy. A biopsy is helpful in differentiating ameloblastoma from ossifying fibroma, osteomyelitis, giant cell tumor, cystic fibrous dysplasia, myeloma, and sarcoma. The best treatment of ameloblastoma is aggressive en bloc resection with simultaneous reconstruction. The high recurrence rate and large tissue defects have been long-standing issues in the treatment of ameloblastoma. Recent molecular developments strongly suggest the possibility of targeted therapy with better outcomes in ameloblastomas. We present a detailed updated narrative review of our current understanding and management of this enigmatic tumor.

Histopathologic Feature of Hyalinization Predicts Recurrence of Conventional/Solid Multicystic Ameloblastomas

The histologic properties of tumors seem to affect their biological behavior, and the same holds good for solid multicystic ameloblastoma (SMA), a benign, locally destructive lesion. Hyalinization is one such histological factor that has been demonstrated to correlate with the biological behavior of neoplasms. The present study aimed to analyze the correlation between the severity of hyalinization (SOH) and the recurrence potential of SMAs. The study was performed on formalin-fixed, paraffin-embedded (FFPE) diagnosed archival cases of SMA, follicular SMA (n = 35) and plexiform SMA (n = 25). The cases were evaluated for SOH and scored from 0–3, and the correlation between SOH and recurrence was analyzed for statistical significance. The clinical parameters of the lesion were analyzed for statistical correlation with recurrence. The SOH significantly correlated with the recurrence of SMA (p = 0.001). The histologic type did not influence the biological behavior of SMA. The location of SMA in the body of the mandible (p = 0.036), multilocular radiolucency (p = 0.001) and root resorption (p = 0.002) also showed strong statistical correlation with recurrence. It is evident from the present study that hyalinization strongly correlates with the biological behavior of SMA. Future studies with advanced investigations could validate the presence of hyalinization and identify the origin of the hyalinized product in SMAs.

Compound-complex odontoma: A rare case report

The World Health Organization (WHO) classifies odontomas as odontogenic tumors, consisting of odontogenic epithelium and ectomesenchyme. They result from developmental abnormalities and, therefore, do not constitute authentic tumors. It is a local malformation that has no growth autonomy. They are rarely symptomatic and are usually discovered accidentally during the realization of a radiographic examination. There are two variants of odontomas: complex and compound. Complex odontomas are made of a mass consisting of an anarchic assembly of mineralized tissue (enamel, dentin, and cementum) and dental pulp; while compound odontomas are consisting of a set of small rudimentary teeth, assembling in clusters. They rarely show the features of both types together. The aim of this work is to report a rare presentation of an odontoma in a 24-year-old male patient, which present the characteristics of both complex and compound variants. Surgical excision of the lesion was performed. Anatomopathological examination confirmed the diagnosis. Clinical and radiological survey does not show any recurrence.

Subepithelial Hyalinisation Predicts Recurrence of Unicystic Ameloblastomas

The inductive effect of hyalinisation and its influence on the biologic behaviour of ameloblastoma variants represent a scarcely researched domain of oral pathology. The complexity of the induction effects within the odontogenic apparatus, with the involvement of both ectodermal and mesodermal tissues, is responsible for diverse histopathological characteristics, hyalinisation being the major feature. The present study aims to deduce for the first time the correlation between the severity of hyalinisation (SOH) and recurrence in three unicystic ameloblastoma (UA) variants, namely, intra-luminal (UA-IL), luminal (UA-L) and mural (UA-M). Retrospectively diagnosed archival cases of UA-IL (n = 08), UA-L (n = 22) and UA-M (n = 30) were assessed for SOH and its correlation with recurrence. A subgroup comparison (between UA-IL/UA-L and UA-M) was also performed. The clinical parameters of the patients were also analysed from files for clinicopathological correlation with recurrence. Results: sub-epithelial hyalinisation (SEH) significantly correlated with the recurrence of UA-L and UA-M (p = 0.001). When the histologic types (UA-L and UA-IL vs. UA-M) were grouped and the correlation of SOH with recurrence was checked, it was observed that both groups (p = 0.001) showed strong statistical correlation. UA-M lesions with multilocular radiolucency (p = 0.001) also showed significant correlation with recurrence. SOH can be a reliable histological predictor of recurrence and of aggressive biologic behaviour in UA. The present study shows a significant association of hyalinisation with the biologic behaviour of UA. Further studies with immunohistochemical investigations could validate the presence of hyalinisation and identify the origin of the hyalinised product in UAs.

Pindborg tumor associated with a supernumerary tooth: a case report

The calcifying epithelial odontogenic tumor is a rare benign neoplasm that accounts for approximately 1% of all odontogenic tumors. Most of the cases occur in the posterior mandible, and a few involve the maxilla. Despite their relatively indolent biological behavior, tumors in the maxilla tend to grow fast. We report the case of a 33-year-old female patient exhibiting swelling in the right maxilla. An isodense area associated with an impacted supernumerary tooth was found on imaging examination. The histopathologic diagnosis was a calcifying epithelial odontogenic tumor. The treatment of choice was surgical removal of the lesion and associated dental elements. The patient has been followed up for 11 months and shows no signs of recurrence. Besides describing this case, we reviewed the literature on the association of calcifying epithelial odontogenic tumors with supernumerary teeth and found two case reports addressing this subject.

Odontogenic carcinosarcoma - A rare case report with review of literature

Odontogenic carcinosarcoma (OCS) is a rare malignant odontogenic tumor (OT) with only a few cases reported in the literature. Its synonyms are ameloblastic carcinosarcoma, malignant mixed OT. It is characterized by a true mixed tumor showing malignant cytology of both epithelial and mesenchymal components. The tumor invaded into adjacent tissues by destroying the bone. A 24-year-old patient visited the outpatient clinic of GITAM Dental College and Hospital, with a chief complaint of growth in the lower right back tooth region for 6 months. Based on clinical and radiographic features, it has been diagnosed as an aggressive central jaw lesion. The patient was further referred for histological examination for confirmatory diagnosis. It has been diagnosed as an adenomatoid OT. The OCS most commonly affects the posterior part of the mandible. A larger number of cases were reported recently, and prolonged follow-up is needed to further clarify the nature of OCS.

A Locally Aggressive Ameloblastic Fibro-Odontoma: A Case Report and Literature Review

Ameloblastic fibro-odontoma (AFO) is a relatively rare, benign noninvasive mixed odontogenic neoplasm derived from epithelial and ectomesenchymal elements of the dental tissues. It usually presents with a mean age of 11.5 years and in the posterior segment of the mandible. It is extremely rare in the posterior maxilla. Although the latest WHO edition classified AFO as developing odontoma, here we present a locally aggressive AFO in a 21-year-old male involving the posterior maxilla and sinus with bone destruction. The patient presents with a two-year history of slowly progressive left facial swelling with malodorous drainage. The CT scan revealed a 5.5 x 4.3 cm well-circumscribed expansile mass with mixed attenuation and peripheral calcification occupying the left maxilla and sinus with bone destruction of the hard palate and orbital rim. According to the literature, most of the AFO cases were treated adequately through a conservative approach with just enucleation or surgical curettage. To our knowledge, our case is the first case treated aggressively with left maxillectomy, palatectomy, and reconstruction surgery because of its radiologic findings, which suggested a locally invasive neoplasm. Histologically, the specimen showed a mixture of proliferative epithelial, mesenchymal tissue elements, and variable amounts of mineralized deposits consisting of enamel matrix and dentinoid deposits, and the final diagnosis was AFO. In conclusion, we present a rare case of AFO with an unusual aggressive presentation, age group, and site involved. The radiographic, histopathologic features, and therapeutic approaches of this unusual locally aggressive tumor are presented with the review of relevant literature.

Concomitant bilateral mandibular cemento-ossifying fibroma and cementoblastoma: case report of an extremely rare occurrence

BACKGROUND

Cemento-ossifying fibroma (COF) and cementoblastoma (CB) are rare benign odontogenic tumors with a predilection for the mandible. Cemento-ossifying fibroma is a fibro-osseous lesion that originates in the tooth bearing areas of jaw and shows cementum-like tissue in a fibrotic stroma. Cementoblastoma is classically related to roots of teeth with the presence of calcified cementum-like material. To date, only a single case of concomitant unilateral COF and CB has been reported in the literature.

CASE PRESENTATION

We present an unusual case of a 37-year-old female who presented with two discrete bilateral swellings in the right and left mandible for 10 years. The larger tumor involved the left posterior mandible with extension anteriorly to the left and right anterior mandibles, and the smaller tumor was present in right posterior mandible. Radiology revealed two distinct lesions involving both sides of mandible. Histopathological examination showed characteristic features of cemento-ossifying fibroma in sections of the larger tumor and cementoblastoma in sections of smaller tumor.

CONCLUSION

This case shows the very unique bilateral co-existence of COF and CB, the second case reported in literature to date.

Ameloblastic Fibro-Odontoma: At the Crossroad Between "Developing Odontoma" and True Odontogenic Tumour

Ameloblastic fibro-odontoma (AFO) is a controversial, rare benign mixed odontogenic tumour that was re-defined as "developing odontoma" in the 2017 WHO classification arguing that once dental hard tissues form, it is programmed to transform into odontoma. However, AFO still remains unclear in terms of its nature. We aimed to analyze a large series of AFOs and compare it to a large series of odontomas (ODs) in an attempt to set cut-off diagnostic parameters between these entities and discuss latest updates on AFO histopathologic, clinical and molecular features. A total of 23 well-documented AFOs were analyzed versus 310 ODs focusing on the age of the patients and size of the lesions. For AFO, mean age was 9.4 ± 3.9 years (range 3-16 years) and mean size (greatest diameter) was 2.9 ± 1.5 cm (range 0.8-5.5 cm). For OD-mean age was 26.5 ± 15.6 years (range 3-81 years), mean size 1.9 ± 0.9 cm (range 1-5 cm). Receiver operating curve (ROC) showed that a cut-off age of 13.5 years and below [area under the curve (AUC) 0.902, 95%CI 0.859-0.945; p < 001; sensitivity 80%, specificity 87%] and a cut-off size of 2.1 cm and above are likely to be associated with AFO (AUC 0.7, 95%CI 0.574-0.827; p = 0.001; sensitivity 57%, specificity 77%). Thus, the combination of age and lesion size may be used to distinguish between lesions of a true neoplastic nature (i.e., AFO) and hamartomatous formation (i.e., OD). Further molecular and genetic specifications are needed to provide a better understanding on the pathogenesis of AFO in support of our suggestion and aid in an accurate classification of AFO.

Maxillary ameloblastic carcinoma: A diagnostic conundrum

Ameloblastic carcinoma (AC) is a rare malignant epithelial proliferation that is associated with an ameloblastoma or histologically resembles an ameloblastoma. It is considered to be an aggressive neoplasm that is locally invasive and spread to regional lymph nodes or distant sites. It requires aggressive surgical treatment, and regular follow-up, therefore, differs from ameloblastoma. Sometimes, ameloblastomas exhibit a mild-to-moderate degree of cytological atypia; hence, in such cases, a correlation should be established between the clinical, radiological and histopathological findings, thus detecting the aggressiveness of the tumor. Here, we present the case report of a 52-year-old male patient diagnosed as AC based on histopathological and immunohistochemical findings.

Large myxomatous odontogenic tumor in the jaw: a case series

Objectives

Myxomatous odontogenic tumors (MOTs) are the third most common odontogenic tumors in the oral and maxillofacial region. Due to its slow-growing, but locally invasive nature, the tumor is usually detected by accident or only when it becomes a large mass, which causes facial deformity.

Materials and Methods

Current study reports three unusual cases of MOT including huge myxoma involve the mandible in middle-aged man, MOT with ossifying fibroma pattern in mandible, and MOT in maxilla of young female patient. The diagnosis and treatment strategy of MOTs was also summarized and updated.

Results

In reported three cases of patients with large MOTs, surgical treatment was indicated with fibular free flap reconstruction in the mandible and plate reconstruction in the maxilla. The tumors were successfully treated with radical resection and did not show signs of recurrence during the follow-up period.

Conclusion

Surgical treatment indication depends on size, the position of the lesion, patient systemic condition and surgeon individual experience. In the case of a large tumor, radical resection and reconstruction is the standard surgical strategy. The conservative surgical treatment including enucleation with wide curettage is still under controversy. The recurrence rate for MOTs is significantly high, up to 30%, therefore long-term follow-up is essential.

Educational Case: Giant Cell Tumor of the Bone in Both the Axial and Appendicular Skeleton

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

New diagnostic molecular markers and biomarkers in odontogenic tumors

Odontogenic tumors comprised of complex heterogeneous lesions that diverse from harmatomas to malignant tumors with different behavior and histology. The etiology of odontogenic tumors is not exactly determined and pathologists deal with challenges in diagnosis of odontogenic tumors because they are rare and obtained experiences are difficult to evaluate. In this study, we describe immunohistochemical and molecular markers in diagnosis of odontogenic tumors besides advanced diagnostic technique. Immunohistochemical features of odontogenic tumors beside the clinical features and radiological finding can help us to determine the correct diagnosis. Although these markers are neither specific nor sensitive enough, but analysis of gene expression provides definitive confirmation of diagnosis. In addition, "-omics" technology detected specific molecular alternation associated with etiology such as genomics, epigenomics, transcriptomics, proteomics and metabolomics. The post transcriptional events such as DNA methylation and chromatin remodeling by histone modification affect the changes in epigenome. Furthermore, non-coding RNAs like micro-RNAs, long noncoding RNA (lncRNA) and small non-coding RNA (snoRNA) play regulatory role and impact odontogenesis. Molecular marker propose their potential role in etiopathogenesis of odontogenic tumors and suitable candidate in diagnostic, prognostic and therapeutic approaches in addition to patient management. For future evaluations, organoid represents in vitro tumor model-study for tumor behavior, metastasis and invasion, drug screening, immunotherapy, clinical trial, hallmarks association with prognosis and evolution of personalized anti-cancer therapy. Moreover, organoid biobank help us to check genetic profile. We think more investigation and studies are needed to gain these knowledges that can shift therapeutic approaches to target therapy.

Cementoblastoma of a primary molar: A rare pediatric occurrence

Cementoblastoma is a relatively uncommon, benign odontogenic mesenchymal tumor that is associated with and attached to the roots of teeth. It is considered to be the only true neoplasm of cemental origin. Its prevalence has been reported to vary from 0.69% to 8% of all odontogenic tumors. The tumor is frequently seen in the second and third decades of life and affects the molar and premolar regions of the mandible predominantly. We herein describe a case of cementoblastoma occurring in association with primary teeth in a 5-year-old male patient with a brief review of literature. Only 20 cases of cementoblastoma involving primary teeth were found after the English literature search, the current case being the 21^st. Moreover, the deciduous teeth-associated cementoblastomas (14 out of 20) show a distinct predilection for the right side of the face. The current case is the seventh one to involve the left side.

Analysis of Protein Immunoexpression and Its Interrelationship in the Pathogenesis of Odontomas and Ameloblastic Fibro-Odontomas: A Systematic Review

Odontomas and ameloblastic fibro-odontomas (AFOs) are the result of a developmental anomaly of odontogenic tissues. A literature review of proteins immunoexpressed in odontomas and AFOs was conducted in order to determine which proteins are involved in the pathogenesis of these lesions. AFO was changed to early odontoma in the 2017 WHO classification and will also be discussed in this article. A literature search was performed in the following electronic databases: PubMed/MEDLINE, Web of Science, Scopus, EMBASE, Lilacs, Cochrane Collaboration Library, and Science Direct. The research question was developed according to the population, intervention, comparison, and outcome (PICO) framework: Which proteins are related to the differentiation of odontomas and what is their interrelationship with AFOs? Thirty articles met all inclusion criteria and were selected for this systematic review, totaling 355 cases of odontomas and 43 cases of AFO. Similar immunoexpression was observed in odontomas and AFOs. Immunoexpression of proteins involved in cell differentiation was higher in compound odontomas than in complex odontomas. Proteins involved in histodifferentiation and enamel formation were more frequent in odontomas. The immunoexpression of enamel matrix proteins differs between odontomas and tooth germs, with their persistence being related to the development of odontomas. Compound odontomas exhibit the highest immunoexpression of proteins involved in cellular histodifferentiation and the Wnt/beta-catenin pathway is involved in tumor formation.

Radicular cysts and Chin implants; An unexpected complication prompting explantation - Case report

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Radicular cysts are benign, odontogenic, and inflammatory in nature that commonly arise in the maxilla.

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No link has been previously found between silicone chin implants and radicular cysts or fistulating radicular cysts.

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We suggest dental panoramic X-ray screening for patients with poor oral hygiene or dental trauma to detect radicular cysts before the operation.

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The decision to proceed with chin implant in a patient known for treated radicular cyst may be unsafe, as the recurrence rate is unknown.

Introduction

Implant-based genioplasty is a simple and safe but not complication-free cosmetic procedure. Patients are commonly briefed about anticipated complications and their management pre-operatively, but few unexpected complications may arise; and this case report is an example. This paper is the first to report a radicular cyst fistulating through chin implant pocket to the skin. Moreover, we present our prevention strategy and recommendations.

Presentation of case

A 39-year-old-lady underwent a silicone implant-based genioplasty that was uneventful. Later, she developed a reddish nodule on the chin necessitating fistulectomy followed by a recurrence leading to explantation. It was not until the second recurrence that a fistulating radicular cyst was discovered and was treated with the help of a dentist.

Discussion

Radicular cysts are benign, inflammatory cysts that arise in a background of dental trauma or caries. No link has been discovered yet between silicone implants and radicular cysts or fistulating cysts. Moreover, we propose that poor oral hygiene could be implicated in the development of these cysts. Dental panoramic X-ray has been used to diagnose radicular cysts, but its efficacy as a screening tool needs to be studied. Finally, the recurrence rate of radicular cysts is unknown.

Conclusion

In a patient with chin implant, radicular cysts could lead to a disastrous outcome. Through history and physical examination, a plastic surgeon should identify patients with poor oral hygiene and dental trauma prior to implant-based genioplasty to arrange for a dental panoramic X-ray. Patients known to have radicular cysts should not undergo an implant-based genioplasty.

Notch in Head and Neck Cancer

Head and neck cancer is a group of neoplastic diseases affecting the facial, oral, and neck region. It is one of the most common cancers worldwide with an aggressive, invasive evolution. Due to the heterogeneity of the tissues affected, it is particularly challenging to study the molecular mechanisms at the basis of these tumors, and to date we are still lacking accurate targets for prevention and therapy. The Notch signaling is involved in a variety of tumorigenic mechanisms, such as regulation of the tumor microenvironment, aberrant intercellular communication, and altered metabolism. Here, we provide an up-to-date review of the role of Notch in head and neck cancer and draw parallels with other types of solid tumors where the Notch pathway plays a crucial role in emergence, maintenance, and progression of the disease. We therefore give a perspective view on the importance of the pathway in neoplastic development in order to define future lines of research and novel therapeutic approaches.

Ameloblastic Carcinoma in a 2-Year-Old Child: A Case Report and Review of the Literature

Ameloblastic carcinoma (AC) is a rare malignant odontogenic tumor in pediatric patients, only 22 cases have been reported in literature since 1932. We present an extremely rare case in which AC occurred in a 2-year-old girl, who had a tumor in the right mandible. Radiographic findings showed a multilocular, poorly defined, and mixed radiolucent-radiopaque lesion in the region of teeth #84 to #85, with bone and tooth root resorption. Computed tomography revealed buccal cortex destruction, tumor infiltration of soft tissue, and enlarged nodes. Incisional biopsy showed histomorphological features of AC. Immunohistochemical analysis exhibited a positive result for Cytokeratin (CK) 19 and overexpression of p53 and Ki67. The patient underwent right hemimandibulectomy and neck dissection. The final pathology was consistent with the initial diagnosis of AC. The patient did not exhibit signs of recurrence or metastasis within 2 years postoperatively. Given the rarity of this disease and the age of the patient, this report constitutes a valuable contribution to the current literature.

Immunohistochemical detection of Tyrosine Kinase receptor (TrK) in follicular and plexiform ameloblastoma - A novel study

Objectives:

The objective is to analyze the immunohistochemical expression pattern of tyrosine kinase receptor (TrK) in ameloblastoma and to compare the immunohistochemical expression pattern of TrK among the histological types of ameloblastoma, follicular and plexiform patterns.

Materials and Methods:

Forty ameloblastomas (20 follicular and 20 plexiform) were immunostained with anti-human TrK mouse IgG monoclonal antibody, and the pattern of staining is statistically analyzed.

Results:

Total 20 (4 follicular and 16 plexiform) out of 40 ameloblastomas showed immunoreactivity to TrK. Only the peripheral preameloblast like tall columnar cells showed reactivity, whereas the stellate reticulum like cells is immunonegative. The staining pattern was membranous in the immunoreactive cells. The Chi-square value for the immunoexpression between follicular and plexiform ameloblastoma was statistically significant with a P < 0.005. The results were studied with the downstream pathways from the literature, and a possible mechanism has been proposed.

Conclusion:

The expression pattern of TrK is found to be more in plexiform ameloblastoma than follicular ameloblastoma.

Vascularized ameloblastoma: A case report and clinicopathologic review of 18 cases from the literature

The notable features of ameloblastoma do not typically include prominent vascularity. However, on rare occasions, vascular ameloblastoma has been described under a variety of names. We present a case of vascularized ameloblastoma that had a bloody return on fine-needle aspiration. The English language literature contains a total of 16 reports (18 cases) of vascular or hemangioma-like ameloblastoma. We reviewed the clinical, pathologic, and radiographic features of the 19 cases, but further study and more cases are needed. The recognition of this variation of ameloblastoma is important for clinicians to note that fine-needle aspiration with a bloody return does not exclude ameloblastoma from diagnostic consideration. We suggest the term vascularized ameloblastoma to avoid any suggestion of a vascular neoplasm.

A multi-centre evaluation of malignant odontogenic tumours in Nigeria

Introduction

odontogenic tumors originate from neoplastic transformation of the remnants of tooth forming apparatus. There are varying degrees of inductive interactions between odontogenic ectomesenchyme and epithelium during odontogenesis, leading to lesions that vary from benign to malignant. Malignant odontogenic tumours (MOTs) are very rare and are classified according to embryonic tissue of origin. Recently, there has been a few changes to the classification of MOTs according to the World Health Organization's (WHO) classification in 2017. This study aims to evaluate and reclassify MOTs, using a multi-centre approach in some major tertiary dental hospitals in Nigeria.

Methods

this study reviewed the clinicopathological data on 63 cases of MOT diagnosed over 25 years in five major tertiary dental hospitals in Nigeria. All MOT cases were reclassified according to the recent revision to the 2017 WHO classification of odontogenic tumours.

Results

from a total of 10,446 biopsies of oral and jaw lesions seen at the 5 study centres over the 25-year study period, 2199 (21.05%) cases were found to be odontogenic tumours (OTs), of which 63 were MOT. MOTs constituted 0.60% of the total biopsy cases and 2.86% of OTs. Odontogenic carcinomas presented with a mean age higher than odontogenic sarcomas. According to our 2017 WHO reclassification of MOTs, odontogenic carcinomas, ameloblastic carcinomas and primary intraosseous carcinomas were found to be the top three lesions, respectively. Carcinosarcomas were found to be extremely rare.

Conclusion

using a multi-centre approach is a robust way to reduce diagnostic challenges associated with rare maxillofacial lesions such as MOTs.