Recurrence rates of intraosseous ameloblastomas of the jaws: A systematic review of conservative versus aggressive treatment approaches and meta-analysis of non-randomized studies

Factors Associated with Recurrence of Ameloblastoma: A Scoping Review

PURPOSE

This scoping review aimed to identify factors associated with the recurrence of ameloblastoma.

METHODS

Systematic searches were conducted in PubMed, Scopus, and EMBASE, based on the board research question: "What factors are related to the recurrence of ameloblastoma?". English-language observational studies addressing the risk and preventive factors associated with recurrent ameloblastoma were included and data were extracted.

RESULTS

Eighty-three retrospective observational studies met the inclusion criteria. The identified prognostic factors for recurrence included: (1) Tumor size/diameter/volume, (2) cortical bone perforation/ soft tissue invasion, (3) multilocular radiolucency, (4) impacted tooth-involving lesions, (5) root resorption, (6) WHO classification - conventional (solid/multicystic) ameloblastoma, (7) histological subtype - mural invasion of unicystic ameloblastoma, (8) conservative treatment modalities - simple enucleation, curettage, and marsupialization, and (9) non-extraction/preservation of involved teeth. No strong evidence linked immunohistochemical expression to recurrence. Interestingly, BRAF p.V600E remained controversial in terms of recurrence, despite being a frequent finding in ameloblastoma.

CONCLUSION

Certain clinical characteristics, radiographic findings, histological subtypes, and treatment choices of ameloblastoma can help identify patients at high risk of recurrence. Further prospective studies to evaluate the prognostic factor model and research on immunohistochemistry are required.

Photodynamic therapy with verteporfin accelerates apoptotic bleb formation in human ameloblastoma

OBJECTIVE

Although benign, ameloblastoma is a locally aggressive lesion in some patients and the development of additional treatments is needed. Verteporfin (VP) is a photosensitizer exhibiting considerable photocytotoxicity in various tumor cells. We aimed to investigate the effects of verteporfin photodynamic therapy (VP PDT) on ameloblastoma.

METHODS

Eighteen patients who underwent surgery for ameloblastoma were randomly selected. We performed an immunohistochemical assessment to investigate the expression of low-density lipoprotein receptor (LDLR) and Yes-associated protein (YAP), targets of VP, in human ameloblastoma tissues and cultured human ameloblastoma cell line (HAM1). The effect of VP PDT on cell proliferation and apoptosis in HAM1 was analyzed.

RESULTS

The expression of LDLR and YAP were detected in human ameloblastoma tissues and HAM1. LDLR expression was significantly higher in patients who had previously undergone surgery than in patients who were receiving it for the first time. The cytotoxic effect of the combination of low-concentration VP administration and laser irradiation was comparable to high-concentration VP administration with and without laser irradiation. The addition of laser irradiation to VP administration significantly accelerated apoptotic bleb formation compared with VP administration alone.

CONCLUSION

VP PDT has the potential to become an additional treatment for large-sized ameloblastoma.

Single-cell transcriptomics reveals cell atlas and identifies cycling tumor cells responsible for recurrence in ameloblastoma

Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms governing tumor initiation and recurrence are poorly understood. Here, we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution. Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response (IR), bone remodeling (BR), tooth development (TD), epithelial development (ED), and cell cycle (CC) signatures. Of note, we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence, which was dominated by the EZH2-mediated program. Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids. These data described the tumor subpopulation and clarified the identity, function, and regulatory mechanism of CC ameloblastoma cells, providing a potential therapeutic target for ameloblastoma.

Clinicopathologic Profile and Surgical Modalities in Mandibular Ameloblastoma: A Descriptive Study

BACKGROUND

Ameloblastoma is a benign neoplasm composed of epithelial tissue with invasive and infiltrative behavior at the local level and a high recurrence rate, with various histopathologic patterns and clinical forms. Approximately 85% of conventional ameloblastomas occur in the mandible, most often in the body, angle, and ascending ramus area. The treatment modalities include both conservative and radical treatments. Postoperative follow-up is most important in the treatment of ameloblastoma.

AIMS AND OBJECTIVES

To describe the clinicopathologic profile of mandibular ameloblastoma in patients undergoing different surgical modalities. The primary objective was to describe the clinicopathologic profile and surgical management of mandibular ameloblastoma in patients aged ≥18 years, who had reported to a tertiary dental care center for follow-up during the study period. The secondary objective was to describe the distribution of comorbidities associated with different surgical modalities and reconstructive methods.

SUBJECTS AND METHODS

A total of 34 patients with mandibular ameloblastoma who underwent various surgical modalities between 2011 and 2021 were studied. Information was collected using a predesigned proforma and statistically analyzed.

RESULTS

Thirty-four review cases of ameloblastoma were included in the study. The patients were analyzed concerning age, sex, site, size, clinical presentation, radiographic pattern, histopathologic subtype, type of surgery, and associated comorbidities. Most cases of mandibular ameloblastoma involve the age of 16 to 55 years. The mean age of occurrence was found to be 35.5±13.2. A female preponderance, a tumor size range of 2 to 4 cm, a multicystic variant, involvement of the mandibular body in the premolar-molar area, root resorption, cortical perforation, and a follicular type of histopathologic pattern were the common presentations. Isolated anterior tumors restricted to the incisor/canine region were not found. The common surgical modalities undertaken were conservative methods such as enucleation, and chemical cauterization, and radical methods such as marginal mandibulectomy and segmental resection. Reconstruction using a titanium plate or free fibular graft was performed in the indicated cases. The common comorbidities included difficulty in chewing and loss of facial contour. Recurrence after surgical treatment was rare. Only 9% of cases developed a recurrence within 5 years. No recurrence was noted in cases treated with radical treatment, whereas 50% of cases treated with conservative methods showed recurrence.

CONCLUSION

The age of occurrence, site, and size of the tumor, cortical perforation, root resorption, histopathologic type, and radiographic patterns are widely considered factors in devising a treatment plan for mandibular ameloblastoma. However, there may be rare instances where these tumors behave differently regardless of their innocuous clinicopathologic presentation. Surgical procedures such as segmental resection and marginal mandibulectomy were found to be promising for the eradication of the tumor, and prevention of recurrences and metastasis. However, conservative measures such as enucleation and chemical cauterization were fraught with an increased risk of tumor recurrence and metastasis. Future studies with a larger sample size should focus on the clinicopathologic characteristics of ameloblastoma to elucidate its varied behavior and develop newer and advanced treatment modalities that would provide better surgical and postsurgical outcomes in affected patients.

Does BRAF mutation status and related clinicopathological factors affect the recurrence rate of ameloblastoma? A systematic review, meta-analysis and metaregression

OBJECTIVES

This review aims to analyse the recurrence rate in BRAFv600e+ and BRAFv600e- ameloblastomas and explore its association with clinicopathological variables.

METHODS

A comprehensive search was conducted using databases including PubMed, Embase, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, Google Scholar and grey literature, without any limitation on start date or language up to 20 June 2023. A random effect meta-analysis was conducted and Metaregression analyses were performed based on available clinicopathological factors.

RESULTS

Fifteen studies met the criteria for meta-analysis of outcomes. There was no significant difference in overall recurrence rates between the two groups (risk difference = 0.001, p-value = 0.987). Increasing male:female ratio in the BRAFv600e+ group was associated with a lower reported recurrence, suggesting a higher recurrence rate in females. The odds of having mandibular lesion were four times higher in BRAFv600e+ cases compared to BRAFv600e- cases (confidence interval: 2.121-7.870, p < 0.001, I2  = 28.37%).

CONCLUSION

Within the BRAFv600e+ group, females showed a higher reported recurrence rate. This specific clinical group may benefit from BRAFv600e mutation investigation and potential upscaled surgical treatment and additional BRAF inhibitor therapy, which needs validation in future studies.

Pseudocarcinomatous Squamous Hyperplasia After Surgical Management Of Pediatric Ameloblastoma: An Immunohistochemical Study

Pseudocarcinomatous squamous hyperplasia (PSH) affecting the jaws is uncommon. The mandible is the most common location, usually as a complication associated with osteomyelitis, medication-related osteonecrosis or osteoradionecrosis. Herein, we report an 8-year-old male patient presenting a solid ameloblastoma, plexiform type, who was treated by segmental mandibulectomy with bone grafting. Three months later, on the underlying graft, a sinus tract was observed, and a small bone fragment was resected which was diagnosed as bone sequestration associated with PSH. After 7-year follow-up, the patient is well, without alterations. To our knowledge, for the first time, we report in detail the immunohistochemical features of PSH which, in addition to epithelial component profile and chronic inflammatory cells, revealed a diffuse infiltration by dendritic cells, suggesting that epithelial cell-immune cell interactions in PSH pathogenesis should also be considered.

A network meta-analysis assessing the effectiveness of various radical and conservative surgical approaches regarding recurrence in treating solid/multicystic ameloblastomas

Multiple treatment approaches have been undertaken to reduce the incidence of recurrence in solid/multicystic ameloblastoma (SMA), both conservative and radical. A network meta-analysis (NMA) was conducted to assess and compare the effectiveness of these various treatment approaches concurrently. This study was reported based on the Preferred Reporting Items for Systematic Reviews for Network Meta-Analysis (PRISMA-NMA) statement. PubMed (MEDLINE), ScienceDirect, Scopus, and Web of Science were searched until August 10, 2021. The NMA was conducted using the STATA program. Of 1153 records identified in the search, seven observational studies with 180 patients were included. Six different treatment approaches were identified. Segmental resection ranked highest for reducing the recurrence rate with the highest SUCRA score (77.7), followed by curettage with cryotherapy (66.9) and marginal resection (49.3). Network inconsistencies and publication bias appeared to be absent. According to the Confidence in Network Meta-Analysis (CINeMa) method, the evidence's certainty was low for all comparisons due to imprecision and within-study bias. In conclusion, this study is the first NMA in the field of ameloblastoma. Segmental resection seemed to be the most effective treatment approach for minimizing recurrence in SMA patients. Nevertheless, weak certainty of evidence makes that the results must be regarded with caution.

Ameloblastoma of the jaws in adult: A retrospective review of local recurrent lesions based on the resection margin in the adjacent apparent healthy tissues

Background

The surgical treatment of ameloblastoma of the jaws remains contentious due to the variable recurrence rate amongst its variants, the tumor's local invasive behavior, and the lack of consensus among surgeons concerning the extent of resection in the contiguous healthy tissues.

Objective

To determine the recurrence rate of ameloblastoma and its association with the resection margins.

Materials and methods

This is a retrospective cohort study of the medical records of patients who underwent surgical resection of the jaws as the primary modality of treatment for ameloblastoma. Clinical data over the 26 years were analyzed for age, gender, site of the lesion, size, radiographic appearance, histopathological sub-type, and the incidence of recurrence post-treatment. Descriptive and bivariate statistics were computed.

Results

A retrospective audit of 234 cases was included in the study that was typical (solid/multicystic) ameloblastoma. The age of patients ranged from 20 to 66 years with a mean age of 33.4 ± 9.6 years, and a male-to-female ratio of 1.2: 1 (P = 0.52). The follicular and plexiform types accounted for the majority of histopathological variants (89.8%; P = 0.000). Overall, 6.8% of cases relapsed after the initial primary surgery. The rate of recurrence was high with a resection margin of 1.0 or 1.5 cm than 2.0 cm (P = 0.001). No case of recurrence was seen with a resection margin of 2.5 cm margin.

Conclusion

A low recurrence rate of 6.8% was noted in our series of cases. A wide 2.5 cm resection margin is recommended in the adjacent healthy tissues.

Recurrent Ameloblastoma: Long Term Outcomes with Free Fibular Bone Graft

Ameloblastoma is a locally aggressive benign neoplasm of jaw that has high propensity to recur. Pathological subtype and intent of surgical excision during primary surgery are two factors that are known to affect the prognosis in these cases. Nevertheless, there are hardly any studies which have studied recurrent ameloblastoma cases. Apart from sharing a tertiary care cancer center's experience in managing a series of recurrent ameloblastoma cases, we discuss some of the recent literature related to pathophysiology and principles related to their surgical management. Retrospective chart review of all those recurrent ameloblastoma cases which were operated between October 2013 and January 2016 and were subsequently followed up for minimum of 3 years. Total of 9 recurrent ameloblastoma cases were operated in the study period. All our patients had less-radical or non-curative intent surgical treatment in the past, and current treatment consisted wide excision of the involved segment of mandible with free fibular reconstruction. Among the 6 patients who were followed up for more than 3 years, none developed recurrence at 56.5 months of mean follow up duration. Almost all these patients had optimal results with good quality of life in terms of oral speech intellectuality and cosmetic perception of self. Complete excision of the involved segment of bone with reconstruction using the composite free fibular graft can provide optimal functional outcomes and can significantly lessen the chances of further recurrences.

Effectiveness of Resective Surgery in Complex Ameloblastoma of the Jaws: A Retrospective Multicenter Observational Study

Ameloblastoma is a rare, benign, odontogenic tumor of epithelial origin, characterized by locally aggressive, expansive growth. Treatment is controversial due to the risk of relapse. The aim of this multicenter retrospective study was to evaluate the effectiveness of complete resection in cases of complex ameloblastoma, which is considered at a higher risk of recurrence. Patients who met at least one of these criteria were included: recurrence, soft-tissue involvement, complete erosion of internal/external cortical walls with involvement of the inferior margin of the mandible, and invasion of the maxillary sinus or nasal cavity. Demographic data, tumor site, type of surgery, histological features, and follow-up information were collected for each patient. The cohort included 55 patients with a mean follow-up of 108 ± 66 months. A multivariate logistic model was used to evaluate variables independently associated with relapse. There were six soft-tissue or maxillary sinus relapses, with a recurrence rate of 10.9%. Most of them arose in patients previously treated. The statistical analysis identified the maxillary location as a fundamental relapse risk factor. En bloc resection with large surgical safety margins seemed to be effective in preventing the relapses. However, complete resection was less effective in preventing recurrences in the soft tissues or maxillary sinus.

Recurrent Ameloblastoma: Clinical Manifestation and Disease-Free Survival Rate

Objectives

Ameloblastoma is a slow-growing epithelial odontogenic neoplasm of the jaws with a high recurrence rate. The main treatment strategies for this lesion are radical or conservative surgical approaches. The aim of the present study was to analyze clinical presentations, histological types, and treatment strategies of recurrent ameloblastoma and to define its disease-free survival (DFS) rate.

Materials and Methods

Twenty-four cases of recurrent ameloblastomas, treated between January 2009 and July 2021, were enrolled in this study. Medical files from each patient, including gender, age, size of the lesion, localization, patient complaints, clinical manifestation, radiographic appearance, histological type, surgical management, and treatment results were reviewed and analyzed retrospectively.

Result

Out of 69 operated primary ameloblastomas, the rate of recurrence was 35%. Out of 24 recurrent cases, 21 developed after conservative treatment and 3 after radical treatment. In most cases, recurrences were found in the mandible (n = 20). A unilocular pattern was predominant in radiographic examination (44%). Estimated 3-year DFS was 84.5 ± 4.8%, and the 5-year and 10-year DFS were 73.0 ± 6.3% and 43.9 ± 8.343.9 ± 8.3%, respectively.

Conclusion

Results obtained in the present retrospective study proved the necessity of long-term follow-up after both conservative and radical treatment approaches. The DFS median in our study was 8 years (95% CI 6 years–10 years). For recurrent cases, radical resection with histologically free margins after exact MRI determination of the ameloblastoma border within the soft tissues should be considered as the method of choice to avoid secondary recurrence.

Ameloblastomas vs recurrent ameloblastomas: a systematic review

Introduction: Ameloblastoma is an odontogenic tumour with high recurrence rate. The objective of the present study was to evaluate existing literature regarding clinical, radiographic, histopathologic features, treatment, and recurrence rate of ameloblastomas and compare it with features of recurrent ameloblastomas. Materials and methods: A systematic review was done based on the PRISMA statement. Search was performed in “Pubmed” database with search terminology “recurrent ameloblastoma”, “ameloblastoma recurrence” for articles published between 2010 and 2020. Data were extracted from full‐text articles and discussed. Results: Out of 515 articles, 16 articles fulfilled the inclusion and exclusion criteria. Data was analysed in two sections. The first with 10 publications assessed features of ameloblastoma in general and their recurrence rate while the second section evaluated features of only recurrent ameloblastomas in 6 publications. There were 234 recurrences in 936 cases with recurrence rate of 23.50%. Male predominance was noted and mandible was commonly affected. Solid/multicystic ameloblastomas formed 74.5% of the tumours and unicystic formed 23.3%. The recurrence rate after conservative treatment was 64.9% and after radical treatment was 12%. Conclusions: The main factors for recurrence were multilocular ameloblastomas, follicular histopathology and conservative treatment.

The epidemiology and management of ameloblastomas: A European multicenter study

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

MicroRNA-1-3p Suppresses Malignant Phenotypes of Ameloblastoma Through Down-Regulating Lysosomal Associated Membrane Protein 2-Mediated Autophagy

Objective: Several clinical trials have suggested that autophagy inhibition is a promising approach for cancer therapy. However, the implications of autophagy in ameloblastoma (AB) remain undiscovered. This study investigated the dysregulated autophagy and its regulatory mechanisms in AB.

Methods: The expression and distribution of autophagy-related proteins including B-cell lymphoma-2-interacting protein-1 (Beclin1), microtubule-associated protein 1 light chain 3 (LC3) II/I and lysosomal associated membrane protein 2 (LAMP2) were detected in AB and normal oral mucosa (NOM) tissues by immunohistochemistry and western blot analyses. Under transmission electron microscopy, the autophagy of AB was observed. LAMP2 was a potential target mRNA of miR-1-3p. Quantitative Real-time PCR (qRT-PCR) analysis was utilized for examining LAMP2 and miR-1-3p in AB tissues as well as AM-1 cells. The correlation between LAMP2 and miR-1-3p was analyzed in AB. After transfection with miR-1-3p mimic or inhibitor, LAMP2 expression, proliferation, migration, and invasion were separately detected in AM-1 cells. Rescue assays were finally presented.

Results: Our results showed that Beclin1 was lowly expressed as well as LC3II/I and LAMP2 were highly expressed in AB. Autophagosomes were observed in AB. MiR-1-3p was lowly expressed in AB, which exhibited negative correlations to LAMP2 expression. MiR-1-3p up-regulation significantly lowered LAMP2 expression in AM-1 cells. Furthermore, miR-1-3p overexpression restrained proliferative, migrated, and invasive capacities of AM-1 cells, which were ameliorated by LAMP2 overexpression.

Conclusion: Our findings demonstrated that miR-1-3p suppressed malignant phenotypes of AB through down-regulating LAMP2-mediated autophagy, which could become an underlying target for AB therapy.

Recurrence Rates of Intraosseous Ameloblastoma Cases With Conservative or Aggressive Treatment: A Systematic Review and Meta-Analysis

Objective

This study aimed to systematically investigate and compare the post-treatment recurrence of intraosseous ameloblastoma in patients treated with conservative or aggressive approaches.

Methods

Systemic searches of PubMed, Medline, Cochrane Library, and Embase databases from inception to October 28, 2020, were conducted. Studies that aimed to evaluate the recurrence of intraosseous ameloblastoma by conservative and aggressive treatment approaches were included.

Results

A total of 20 studies with 942 ameloblastoma cases were included. Fourteen studies included patients with ameloblastoma who received conservative treatment, and 16 studies reported the overall recurrence rate for patients undergoing aggressive treatment. The pooled results indicated that the recurrence rate for aggressive treatment [0.12, 95% confidence interval (CI) = 0.09–0.16] was significantly lower than that for conservative treatment, with a recurrence rate of 0.30 (95% CI = 0.23–0.39). Similar results were obtained when stratifying the participants by the histological classification. When trying stratification analysis following the original included studies, multicystic ameloblastoma presented a much higher recurrence rate than solid and unicystic ameloblastomas.

Conclusion

These findings supported the hypothesis that aggressive treatment might lead to a lower recurrence rate than conservative treatment. More studies and meta-analyses following the new histological classification of ameloblastomas are needed to validate and support the findings.

Effectiveness of marsupialisation and decompression on the reduction of cystic jaw lesions: a systematic review

In this study, we aimed to systematically review and critically appraise the available literature concerning the effectiveness of marsupialisation and decompression on the reduction of cystic jaw lesions. The 'Preferred Reporting Items for Systematic Reviews and Meta-Analysis' guidelines were followed and the study protocol was registered at the 'International Prospective Register of Systematic Reviews' (CRD42019116099). Six main databases were searched: Embase, LILACS, PubMed, Scopus, The Cochrane Library, and Web of Science. Searches were complemented with three grey literature sources: Google Scholar, ProQuest, and Open Grey. Any reduction measures, compared with preoperative status or other procedures, were considered. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Tool. Thirty-one studies were included, of which five were judged with low, 24 with moderate, and two with high risk of bias. Considering surgical approach, 20 studies assessed the decompression and 11 the marsupialisation technique. Most studies considered these techniques as preliminary treatments, followed by enucleation. From 1088 lesions found, most were odontogenic keratocysts (33.8%), followed by unicystic ameloblastomas (21.0%), dentigerous cysts (20.6%), and radicular cysts (8.4%). Large lesions and younger individuals frequently presented more favourable responses to treatment and anatomical location was not associated with lesion reduction overall. The intervention duration generally ranged between one to two years. In conclusion, marsupialisation and decompression were mostly considered as preliminary treatments, followed by enucleation. Lesion reduction was generally considered insufficient for these techniques to be used as definitive therapies, although benefits concerning the diminished invasiveness of the secondary surgery were often proposed.

Developmental Odontogenic Lesions Associated with the Crown of an Impacted Tooth: A Guide to the Distinct Histologic Features Required for Classification

Odontogenic cysts are categorized as inflammatory and developmental. Of the developmental odontogenic cysts, the dentigerous cyst is the most common and by definition is attached to the cervical region of an unerupted tooth. The cyst envelops the crown forming a sac. However, there are other developmental cysts, and rarely, odontogenic tumors, that can have a similar clinical and radiographic presentation as dentigerous cyst, including odontogenic keratocyst, orthokeratinized odontogenic cyst and ameloblastoma, unicystic type. Understanding the key histologic differences of these cysts will aid the pathologist to correctly diagnose these lesions, ensuring appropriate clinical management.

Controversies in ameloblastoma management: evaluation of decision making, based on a retrospective analysis

BACKGROUND

The ameloblastoma management is still challenging to the high recurrence rates and significant morbidity associated with radical treatment. The purpose of this 10-year retrospective study was to analyze the influence of ameloblastoma type and treatment strategy on the long-term outcomes and recurrence rates.

MATERIAL AND METHODS

The retrospective analyses of 64 histologically-confirmed ameloblastoma cases was performed. The possible risk factors for recurrence and the development of complications were estimated statistically.

RESULTS

The treatment strategy applied for this group of patients was the following: thirty-four patients (53.1%) were treated conservatively with enucleation or extended bone curettage. Radical treatment (bone resection) was applied in 30 (46.9%) cases. The follow-up period ranged from 2 to 10 years (mean value 4.28 ± 3,26). General recurrence rate consisted 32.8%. This study did not find significant correlations between clinical or histopathological features of the ameloblastoma and the recurrence rate. The only factor that significantly influence recurrence rate was the treatment strategy (41% in conservative treatment vs 15% in radical treatment, p<0.05). Postoperative complications were observed in 42 patients (65.6%) and included face asymmetry and disfigurement (17.2%), temporary paresthesia of the inferior alveolar nerve (IAN) - 23.4%, permanent paresthesia of IAN - 20.3%, paresis of a marginal branch of the facial nerve - 6.3%, infection 12.5%, and swelling - 20.3%. The complication rates, esthetic and functional deficiency were significantly higher in radically treated patients (p<0.05) Conclusions: Our study confirms that higher recurrence rate is associated with conservative treatment for ameloblastoma, while radical treatment leads to an increased number of postoperative complications that affect the patient's quality of life.

Conceptual changes in ameloblastoma: Suggested re-classification of a "veteran" tumor

OBJECTIVES

The merging of ameloblastoma (AM) with mural unicystic ameloblastoma (UAM-M) was suggested by the 2017 WHO based on similar treatment needs. In an international multicenter study, we investigated the characteristics of their merged product (merged-AM) and raised the possibility of unifying AM and UAM (total-AM).

MATERIALS AND METHODS

AM and UAM (luminal/intraluminal/mural), separate and combined, were analyzed for demographic/clinical/radiological features. ANOVA and chi-square tests were followed by univariate and multivariate analyses, and significance was set at p < .05.

RESULTS

The patients' mean age was 39.6 ± 20.3 years in merged-AM (147 AM, 76 UAM-M), 45.1 ± 19.4 years in AM (p = .009). Merged-AM comprised 51.3% multilocular/48.7% unilocular tumors, AM comprised 72.5%/27.5%, respectively (p < .001). Merged-AM was associated with impacted teeth in 30.8%, AM in 18% (p = .023). The probability of merged-AM for multilocularity increased by 2.4% per year of age (95%CI 0.6-4.2, p = .009). Association with impacted teeth decreased by 7.9% per year of age (95%CI 1.9-14.39, p = .009). Merged-AM did not differ from total-AM (p > .05).

CONCLUSIONS

Merged-AM partially differed from AM, but differences appeared to diminish in an age/time-wise manner. Merged-AM and total-AM were nearly indistinguishable. Therefore, AM and UAM may be considered a continuous spectrum of one type of tumor, further necessitating revision of the treatment approaches.

BRAF V600E mutation-specific immunohistochemical analysis in ameloblastomas: a 44-patient cohort study from a single institution

PURPOSE

The aim of this study is to investigate the presence and prevalence of BRAF V600E mutation in ameloblastomas using anti-BRAF V600E monoclonal antibody (VE1 clone) and to identify any clinicopathologic correlation with BRAF V600E mutation in ameloblastoma.

MATERIALS AND METHODS

The pathology files of the Department of Oral Pathology and Oral Medicine, Faculty of Dentistry, Lagos State University College of Medicine, Lagos, Nigeria, were searched for the diagnosis of ameloblastoma from 2016 to 2020. Archived non-decalcified formalin-fixed paraffin-embedded tissue underwent immunohistochemistry using anti-BRAF V600E antibody at the University of Pittsburgh, Pennsylvania. Clinicopathologic data such as age at diagnosis, gender, jaw bone involved (mandible or maxilla), tumor location (anterior or posterior) and histologic subtype were collected. The clinicopathologic parameters were analyzed using Chi-square test and Fisher's exact test according to the BRAF status.

RESULTS

Forty-four cases of ameloblastoma were retrieved. The male to female ratio was 1.32:1. The average age of patients at diagnosis was 33.3 years. Thirty-nine cases were located in the mandible and 5 cases in the maxilla. Only cases in the mandible were positive for anti-BRAF V600E antibody (n = 15/39; 38.5%). There was a significant correlation between BRAF V600E expression in mandibular tumors and histologic subtype (p = 0.02); however, no significance was observed for gender, age and tumor location.

CONCLUSION

BRAF V600E mutation preferentially occurs in mandibular ameloblastomas, especially in non-plexiform ameloblastomas. These patients may benefit therapeutically from the use of BRAF inhibitors.

Enucleation and surgical stent as a treatment strategy for a large unicystic ameloblastoma: Case report and review of literature

•

Ameloblastoma has a locally invasive and aggressive nature and high recurrence rate.

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A conservative approach and a radical resection approach have been suggested.

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Radical resection may lead to esthetic, functional, and psychological sequelae.

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First use of surgical stent with conservative management for ameloblastoma.

Introduction

Ameloblastoma is a benign neoplasm of odontogenic origin with local invasive characteristics and a high recurrence rate. It compromised 1% of the jaw's cysts and tumors with only 10–15% in children.

Presentation of case

A 14-year-old boy sought treatment for a painless swelling involving the right side of the face started one year ago. The intra-oral examination displayed a firm mass associated with 46, 47 teeth, and the angle of the mandible. The radiographic examination revealed a large well-defined homogeneous radiolucency extending from the 46 region to involve the angle and extending towards the coronoid and condylar processes. An incisional biopsy confirmed the diagnosis of unicystic ameloblastoma. Treatment was planned according to the patient’s age: Phase I: Surgical enucleation. Phase II: Construction and insertion of a surgical stent. Phase III: Construction of a transitional acrylic Kennedy class II partial denture. Phase IV: the patient is scheduled for a definitive implant-supported prosthesis at 18 years old.

Discussion

The management of ameloblastoma is influenced by the age of the patient, the extension, duration, and position of the lesion, and the histopathological variants. Several authors recommended enucleation as a conservative treatment approach to eliminate the esthetical, functional, and psychological squeals associated with the radical approach. The use of a surgical stent protects the enucleated cavity and promote tissue healing.

Conclusion

Enucleation and subsequent surgical stent not only eliminates the disease, but also preserves the bone structure, prevents the facial disfigurement, and significantly improve the patient’s esthetic, mastication, oral health, and quality of life.

Management of Ameloblastoma with Free Tissue Flap in Comparison with Other Reconstructive Options Available

Aim

To review the management and reconstruction of ameloblastoma of mandible in different age groups over a period of 11 years.

Methodology

This retrospective study includes 51 cases operated in the Maxillofacial Unit, Bhagwan Mahaveer Jain Hospital, Bangalore, from the year 2007 to 2017. The data of these patients were collected to record demographic data such as age, gender with site of tumour and type of reconstruction after resection, follow-up period and incidence of complications. This study evaluated the outcome in terms of aesthetics, function and choice of reconstruction in different age groups.

Results

Most patients were of 21-40 age group. 37 (72.5%) were found to be unicystic ameloblastoma. 41 (80.3%) patients underwent reconstruction following the resection. There was a change in trend seen over a period of time with free grafts and reconstruction plate being historical, except in special situations like old age and unfit patients. According to one-way ANOVA and Tukey's post hoc analysis, free flaps were known to take a longer duration (mean = 503 min) compared to other modes of reconstruction. However, free grafts and free flaps were demonstrated to have a good facial contour and speech with most cases dentally rehabilitated with implants. Among the complications, 1 (16%) case with reconstruction plate showed screw loosening, 2 (28%) cases with free grafts showed graft exposure, and 1 (3.5%) case with free flap had venous congestion, making free flaps the most reliable option.

Conclusion

Free fibula is the gold standard of mandible reconstruction, but depending on age, medical condition, economic status and size of the defect other modes of reconstruction can be chosen with the acceptance of suboptimal results.

Adjunctive Strategies for Benign Maxillofacial Pathology

Benign cysts and neoplasms of the maxillofacial region can vary in behavior, with some growing rapidly and resulting in destruction of surrounding structures. Despite their benign histology, many require often-morbid treatment to prevent recurrence of these lesions. Several less invasive and adjunctive medical treatments have been developed to lessen the morbidity of surgical treatment. As the molecular and genomic pathogenesis of these lesions is better understood, more directed treatments may lessen the burden for patients.

Upregulation of eukaryotic translation initiation factor 3 subunit a promotes cell survival in ameloblastoma

OBJECTIVES

This study aimed to detect the expression of eukaryotic translation initiation factor 3 subunit a (eIF3a) in ameloblastoma (AB) tissues compared with normal oral mucosa (NOM) tissues and investigate the roles of eIF3a in the immortalized ameloblastoma cell line (AM-1) cell proliferation and apoptosis.

STUDY DESIGN

We performed immunohistochemistry to determine the expression of eIF3a in AB tissues (n = 83) and NOM tissues (n = 20). Real time-quantitative polymerase chain reaction and Western blot analyses were conducted with AB tissues (n = 30) and NOM tissues (n = 6). The correlation between eIF3a expression and the clinical/pathologic features of patients with AB is also presented. The functional role of eIF3a in AM-1 cells was assessed with lentiviral vector-mediated shRNA (small hairpin RNA).

RESULTS

Our results indicated that eIF3a was significantly upregulated in AB. Additionally, eIF3a knockdown in AM-1 cells significantly inhibited cell proliferation and promoted apoptosis.

CONCLUSIONS

These data indicate that eIF3a facilitates the survival of AB cells and may serve as a promising therapeutic target in AB.

Radical vs conservative treatment of intraosseous ameloblastoma: Systematic review and meta-analysis

OBJECTIVES

The aim of the present study was to assess the outcomes of radical and conservative treatment approaches of solid/multicystic and unicystic ameloblastoma in terms of recurrence rates.

MATERIAL AND METHODS

A systematic review and meta-analysis was conducted based on the PRISMA statement. Search was performed using PubMed, Embase, SCOPUS, and Web of Science for articles published from January 1969 until March 2018. Quality assessment of the selected articles was conducted using the Quality Appraisal of Case Series Studies Checklist. The meta-analysis was performed using the MedCalc program.

RESULTS

The search strategy yielded 6,984 articles; 20 studies met the eligibility criteria and were included in the meta-analysis. The pooled recurrence rate of solid/multicystic ameloblastomas following radical treatment was 8%, while conservative treatment caused recurrences in 41%. For unicystic ameloblastomas, these values were 3% and 21%, respectively. The risk of recurrences in both types of ameloblastomas following radical treatment was lower than following conservative treatment.

CONCLUSIONS

The present study showed statistically significant differences in recurrence favoring radical treatment for both unicystic and solid/multicystic ameloblastoma. The solid/multicystic type showed more recurrences than the unicystic type. Unfortunately, since only retrospective studies were available, the evidence is less strong as wished for.

Is conservative surgery a better choice for the solid/multicystic ameloblastoma than radical surgery regarding recurrence? A systematic review

PURPOSE

Determine if conservative surgery of primary solid/multicystic ameloblastoma (SMA) is capable of decreasing the recurrence rate as effectively as radical surgery.

METHODS

We searched in MEDLINE, Web of Science, Scopus and Cochrane Library for original studies reporting on the conservative or radical treatment of primary SMA and the related recurrence rate. All selected data were independently assessed. Meta-analysis was performed and the Relative Risk (RR) of recurrence with a confidence interval of 95% was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 2647 records retrieved were reduced to 7 studies to be qualitatively assessed and 4 studies were included in the meta-analysis. RR of 1.88 [0.59, 5.95] of the pooled values pointed that recurrence rate after the conservative surgery is neither comparable nor lower than the radical surgery (P = 0.28).

CONCLUSIONS

Conservative surgery does not reduce the recurrence rate as efficiently as radical surgery for primary SMA. However, there is not enough evidence to support this statement.

Distraction Osteogenesis of Fibula Graft for Mandibular Reconstruction Following Ameloblastoma Ablation

BACKGROUND

Resection of maxillofacial may cause a series of complications such as loss of facial deformity, dysfunction, and psychological distress. Mandibular reconstruction following resection still remains difficult.

METHODS

A 18-year-old male patient with mandibular ameloblastoma was admitted in the hospital of stomatology. The tumor was dissected and the defect was reconstructed using vascularized fibula graft. One year later, distraction osteogenesis (DO) was performed on the fibula graft to augment the alveolar bone for dental implants. Panoramic radiographs, computed tomography, and clinical photographs were taken. Five months after completion of distraction, the distraction device was removed.

RESULTS

Panoramic radiographs, computed tomography, and clinical photographs showed the good healing after fibula graft for mandibular reconstruction following ameloblastoma ablation and satisfied alveolar bone with good width and height for dental implants after DO.

CONCLUSIONS

This report suggests that DO of fibula graft following mandibular reconstruction was an efficient method to augment the alveolar bone for dental implants.

Ameloblastoma: Management and Outcome

Introduction Ameloblastoma is a locally destructive tumor with a propensity for recurrence if not entirely excised. Management of ameloblastoma poses a challenge for all involved in the field of head and neck surgery because successful treatment requires not only adequate resection but also a functional and aesthetically acceptable reconstruction of the residual defect. Methods Patients who had histologically proven ameloblastoma between 1991 and 2009 were identified from the database of Aga Khan University Hospital. A review of all medical records, radiological images, operative reports and pathology reports was undertaken. Results A total of 15 patients with histologically confirmed ameloblastoma were identified. Out of 15 patients nine were males and six were females with age range from 20 to 60 years (mean age 43 years). The most common symptom found in our patient group was painless facial swelling. In 13 patients the origin of tumor was mandible and in the remaining two the tumor originated from maxilla. Eleven out of 15 patients underwent segmental mandibulectomy, two had maxillectomy and two had enucleation. All patients who underwent segmental mandibulectomy required reconstruction. Reconstruction was done with microsurgical free tissue transfer in eight patients, non-vascularized iliac crest bone graft was used in one patient and two had plating only. All free flaps survived with no evidence of flap loss. The mean follow-up was eight years. There was no evidence of graft failure which was used in one patient. Complication was seen in only one of our patients in the form of plate exposure. Recurrence was seen in two of our cases who primarily underwent enucleation. All patients had satisfactory speech, cosmesis and mastication. Conclusion The management of ameloblastoma still poses a big challenge in spite of being the most common odontogenic tumor. In our study we have found that segmental mandibulectomy with disease-free margin of around 1 cm and immediate reconstruction with free tissue transfer have shown good results.

Biological profile of ameloblastoma and its location in the jaw in 1246 Nigerians

OBJECTIVES

Ameloblastoma is a benign, slow-growing, locally invasive epithelial tumor of odontogenic origin, with unlimited growth capacity and a strong tendency to recur. This multicentric study analyzed ameloblastoma diagnosed in Nigeria among different ethnic groups.

STUDY DESIGN

This retrospective study included ameloblastoma cases diagnosed from 1964 to 2017 at 10 hospitals or medical centers in Nigeria. Age, sex, tribe, and location of the ameloblastoma in the jaw were analyzed. Associations between variables were tested by using χ² and Fisher's exact test.

RESULTS

A total of 1246 ameloblastoma cases were recorded (mean patient age 32.51 ± 14.54 years; range 4-86 years; male-to-female ratio 1.2:1). Approximately 60% of ameloblastoma cases occurred in young adults (age range 18-40 years). Ninety-eight lesions were located in the maxilla and 1103 in the mandible; the posterior mandible was the most common site (31.3% on the right and 26.5% on the left, respectively), followed by the anterior (26.0%) mandible. No significant differences were noted in the distribution of ameloblastoma within the tribes with respect to age (P = .92) and sex (P = .71).

CONCLUSIONS

The mandible is a common site of ameloblastoma in patients in Nigeria, and in most cases, it occurs in young adults. Early presentation, diagnosis, and treatment are important to reduce postoperative disfigurement and morbidity.

Ameloblastic Carcinoma In Situ: Review of Literature and a Case Presentation in a Pediatric Patient

Ameloblastic carcinomas are rare malignant lesions with 3 mandibular pediatric cases reported in the literature. We present a case of ameloblastic carcinoma in situ in a 15-year-old male with a right mandibular cystic lesion on computed tomography. The incisional biopsy revealed plexiform ameloblastoma. Due to the infiltrating and aggressive nature of the tumor, the patient underwent hemimandibulectomy and immediate reconstruction with a vascularized osteocutaneous fibula free flap. The final pathology was read as ameloblastic carcinoma in situ. Given the rarity of this disease in the pediatric population, this case report may be a valuable addition to the current literature.

Recent trends in the treatment of benign odontogenic tumors

PURPOSE OF REVIEW

The management of benign, locally aggressive odontogenic tumors, namely, keratocystic odontogenic tumors (KOTs) and ameloblastomas, can be challenging. The purpose of this article is to briefly summarize important features of these lesions and review recent trends in the literature regarding their treatment.

RECENT FINDINGS

Currently, KOTs are frequently treated with a conservative approach consisting of enucleation and adjuvant decompression or local microablation with peripheral ostectomies, Carnoy's solution, or cryotherapy. Conversely, ameloblastomas generally require marginal or segmental resection followed by reconstruction using local bone regeneration techniques or vascularized osteocutaneous free flaps, respectively. Bone regeneration techniques have improved with the use of autogenous progenitor cells held in place by autogenous or alloplastic scaffolding. Esthetic results for free flap reconstruction have improved with the use of inconspicuous surgical approaches utilizing intraoral or rhytidectomy incisions. Molecular markers for both neoplasms are being investigated as potential targets for chemotherapeutic agents.

SUMMARY

Excluding hamartomas (i.e., odontomas), KOTs and ameloblastomas are the most common benign odontogenic lesions. Their management is often complicated by their locally infiltrative behavior, responsible for high rates of recurrence. Simple enucleation or excision of these lesions has proven insufficient. When left untreated, these lesions are capable of causing severe disfigurement and loss of function. Knowledge regarding current best practices and potential future therapeutics is imperative to well treated and effective disease management.

Conservative management (marsupialization) of unicystic ameloblastoma: literature review and a case report

Background

In this study, we present a case of unicystic ameloblastoma (UA) treated by marsupialization followed by surgical enucleation as a conservative approach. UA is a rare, benign, less aggressive, and less invasive variant of ameloblastoma that is observed quite often in younger patients. Radical approaches have effects on the physical and psychological development of a growing young patient; therefore, conservative approaches are widely used for UA management in children.

Case presentation

This report described a case of an 11-year-old girl with UA of the mandibular molar–ramus area, which also involved impaction of the second and third molars. The lesion was marsupialized, and 31 months after marsupialization, surgical enucleation was performed with extraction of the impacted third molar. The second molar, which was preserved, spontaneously and completely erupted. No recurrence was observed during a 49-month follow-up.

Conclusions

Conservative treatments for UA in young patients have more advantages. Our results provide evidence that marsupialization is effective in regressing the lesion size to ease complete removal, preserving mandibular growth, maintaining involved second molar, and promoting the eruption of the tooth.

Mesenchymal Stromal Cell-Derived Interleukin-6 Promotes Epithelial-Mesenchymal Transition and Acquisition of Epithelial Stem-Like Cell Properties in Ameloblastoma Epithelial Cells

Epithelial-mesenchymal transition (EMT), a biological process associated with cancer stem-like or cancer-initiating cell formation, contributes to the invasiveness, metastasis, drug resistance, and recurrence of the malignant tumors; it remains to be determined whether similar processes contribute to the pathogenesis and progression of ameloblastoma (AM), a benign but locally invasive odontogenic neoplasm. Here, we demonstrated that EMT- and stem cell-related genes were expressed in the epithelial islands of the most common histologic variant subtype, the follicular AM. Our results revealed elevated interleukin (IL)-6 signals that were differentially expressed in the stromal compartment of the follicular AM. To explore the stromal effect on tumor pathogenesis, we isolated and characterized both mesenchymal stromal cells (AM-MSCs) and epithelial cells (AM-EpiCs) from follicular AM and demonstrated that, in in vitro culture, AM-MSCs secreted a significantly higher level of IL-6 as compared to the counterpart AM-EpiCs. Furthermore, both in vitro and in vivo studies revealed that exogenous and AM-MSC-derived IL-6 induced the expression of EMT- and stem cell-related genes in AM-EpiCs, whereas such effects were significantly abrogated either by a specific inhibitor of STAT3 or ERK1/2, or by knockdown of Slug gene expression. These findings suggest that AM-MSC-derived IL-6 promotes tumor-stem like cell formation by inducing EMT process in AM-EpiCs through STAT3 and ERK1/2-mediated signaling pathways, implying a role in the etiology and progression of the benign but locally invasive neoplasm. Stem Cells 2017;35:2083-2094.

Ameloblastoma: current etiopathological concepts and management

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

Unicystic Ameloblastoma: Rehabilitation with Chin Graft Harvested and Implant-Supported Fixed Prosthesis

Objective

The objective is to present a clinical case of a 38-year-old male with a maxillary unicystic ameloblastoma treated by means of tumor block resection followed by chin-harvested graft placement in order to place two dental implants for esthetic and functional rehabilitation.

Methods

Ameloblastoma is a benign odontogenic tumor characterized by local aggression and a high rate of recurrence; the latter partly depends on how it is treated. Complete resection of the tumor, which usually prevents recurrence, produces bone defects of varying size that must be reconstructed later on. In most cases this is done using bone grafts and implant-supported prostheses. Grafts harvested from the chin are relatively easy to obtain and enjoy a fairly uneventful post-operative with few complications; they are suitable for cases in which the defect generated by resection is of small size.

Results

Functional and esthetic rehabilitation and the tumor has not relapsed during a 7-year follow-up.

Conclusion

Tumor block resection followed by chin-harvested graft placement and dental implants is a safe treatment for patients with unicystic ameloblastoma.

Regeneration of mandibular ameloblastoma defect with the help of autologous dental pulp stem cells and buccal pad of fat stromal vascular fraction

Ameloblastoma is benign odontogenic tumor, which is locally aggressive in behavior. Till date, the treatment of choice is resection and reconstruction using a variety of modalities. Inadequate resection may lead to many complications such as bone deformity and dysfunction. This report is about a 14-year-old male with ameloblastoma treated with autologous dental pulp stem cells (DPSCs) and stromal vascular fraction (SVF) and evidence of bone regeneration. Marsupialization was performed; tooth was extracted and sent for DPSC cultivation. On the day of surgery, SVF was processed from buccal pad of fat, and platelet-rich fibrin (PRF) was prepared from patient's peripheral blood. During the procedure, labial plate resection and curating of tumor lining were done. After which, a mesh packed with SyboGraft T-plug, prepared SVF, DPSCs, and PRF were placed over lingual cortex and pressure dressing was done. After the 1^st month of surgery the postoperative course was uneventful, the wound shrinkage led to exposure of mesh in the intraoral region. Removal of exposed mesh was done. The correction surgery with removal of part of mesh and primary closure was achieved with SyboGraft plug, SVF and PRF. Enhanced bone formation was seen in post-operative OPG and CT Scan after 10^th month. In this article, we propose an innovative approach to manage these cases by using a combination of autologous DPSC and buccal pad of fat SVF to regenerate a mandibular defect left by the resection of an ameloblastoma with 1.5 year follow-up. We were able to demonstrate bone regeneration using this technique with no recurrence of tumor.

BRAFV600E mutation in the diagnosis of unicystic ameloblastoma

BACKGROUND

Unicystic ameloblastoma, an odontogenic neoplasm, presents clinical and radiographic similarities with dentigerous and radicular cysts, non-neoplastic lesions. It is not always possible to reach a final diagnosis with the incisional biopsy, leading to inappropriate treatment. The BRAFV600E activating mutation has been reported in a high proportion of ameloblastomas. The purpose of the study was to assess the utility of the detection of the BRAFV600E mutation in the differential diagnosis of unicystic ameloblastoma with dentigerous and radicular cysts.

METHODS

Twenty-six archival samples were included, comprising eight unicystic ameloblastomas (UAs), nine dentigerous and nine radicular cysts. The mutation was assessed in all samples by anti-BRAFV600E (clone VE1) immunohistochemistry (IHC) and by TaqMan mutation detection qPCR assay. Sanger sequencing was further carried out when samples showed conflicting results in the IHC and qPCR.

RESULTS

Although all UAs (8/8) showed positive uniform BRAFV600E staining along the epithelial lining length, the mutation was not confirmed by qPCR and Sanger sequencing in three samples. Positive staining for the BRAFV600E protein was observed in one dentigerous cyst, but it was not confirmed by the molecular methods. Furthermore, 2/9 dentigerous cysts and 2/9 radicular cysts showed non-specific immunostaining of the epithelium or plasma cells. None of the dentigerous or radicular cysts cases presented the BRAFV600E mutation in the qPCR assay.

CONCLUSIONS

The BRAFV600E antibody (clone VE1) IHC may show non-specific staining, but molecular assays may be useful for the diagnosis of unicystic ameloblastoma, in conjunction with clinical, radiological and histopathological features.

A case report on desmoplastic ameloblastoma of anterior mandible

BACKGROUND

Desmoplastic ameloblastoma (DA) is a rare variant that accounts for approximately 4-13% of ameloblastoma, displaying significant differences in anatomical site, imaging, and histologic appearance. It has been included in WHO classification of head and neck tumor (WHO-2005) as a variant of ameloblastoma. The tumor resembles benign fibro-osseous lesion for being frequently occurring in the anterior region of jaws as a mixed radiopaque-radiolucent lesion.

CASE PRESENTATION

We present a case of DA in a 43-year-old female with a painless swelling in the anterior region of mandible. No fluid was evident on fine needle aspiration. A mixed lesion with multilocular appearance was evident on both panoramic radiographs as well as computed tomography scan. An incisional biopsy confirmed it to be a case of desmoplastic ameloblastoma. Segmental mandibulectomy was performed from teeth 35 to 44. The patient is on routine follow-up and is currently free of ailment.

CONCLUSIONS

The present case deserves emphasis because of its unfamiliar appearance, potentially aggressive nature and deceptive radiologic appearance maximizing the chances of misdiagnosis. So, the clinician should be alert enough to include desmoplastic ameloblastoma in differential diagnosis of any lesion/growth with mixed radiolucent-radiopaque appearance having ill-defined borders and occurring in anterior maxilla or mandible.

Ameloblastomas of the mandible and maxilla

PURPOSE OF REVIEW

This review focuses on issues in managing ameloblastomas of the mandible and maxilla. We will refer to current practice in the treatment of ameloblastomas based on the available evidence.

RECENT FINDINGS

Recent reviews have been trying to establish natural history, growth patterns and malignant potential. This provides the clinicians and the patients with useful prognostic information. Controversies in management of ameloblastomas in relation to the type, age and site exist. This paper aims to categorize these issues. More recently, the authors have adopted the staged treatment approach as an additional step to ensure margin clearance.

SUMMARY

Current evidence favours radical resection to provide better control rates. This applies to maxillary lesions of all ages, and solid mandibular lesions in adults (>18 years) where growth has ceased and the patient has matured enough to withstand the impact of resection and reconstruction. Conservative management is advocated for unicystic lesions with good control rates. In children and adolescents, a conservative approach is recommended. This approach aids to minimize both psychological and the impact on growth. Furthermore, most of the lesions are unicystic and the recurrent lesions have been shown to be much smaller and can be managed promptly within a good healthcare system.