Maxillary Ameloblastoma: A Review With Clinical, Histological and Prognostic Data of a Rare Tumor

Implant-supported prosthetic rehabilitation after Ameloblastomas treatment: a systematic review

BACKGROUND

Ameloblastoma (AM), the benign counterpart of ameloblastic carcinoma, is a benign odontogenic tumor of epithelial origin, naturally aggressive, with unlimited growth potential and a high tendency to relapse if not adequately removed. Patients with AM treated surgically can benefit from dental implant therapy, promoting oral rehabilitation and improving their quality of life. The present study aimed to determine the survival rate of dental implants placed after surgical treatment of patients affected by AM. In addition, there were two secondary objectives: 1) To evaluate which dental implant loading protocols are most frequently used and 2) To determine the type of prosthetic restoration most commonly used in these patients.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed during the study. Searches were performed in three databases (PubMed/MEDLINE, Scopus, and Google Scholar) until November 2023. Additionally, the electronic search was enriched by an iterative hand search of journals related to oral pathology and medicine, maxillofacial surgery, and oral prosthodontics and implantology. Only reports and case series in English from January 2003 to date were included. The Joanna Briggs Institute tool (JBI-Case Reports/Case Series) was used for the study quality assessment.

RESULTS

The total number of patients and implants studied were 64 and 271, respectively, all with surgically treated AM. The patient's ages ranged from 8 to 79 years, with a mean (SD) age of 37.3 ± 16.4. Fifty-three percent were male and 47% were female. The range of follow-up duration was 1 to 22 years. An implant survival/success rate of 98.1% was reported. In addition, most of them were conventionally loaded (38.3%). Hybrid implant-supported fixed dentures were the most commonly used by prosthodontists (53%).

CONCLUSIONS

Oral rehabilitation with dental implants inserted in free flaps for orofacial reconstruction in surgically treated patients with AM can be considered a safe and successful treatment modality.

Heat Shock Proteins' Expression Profiles in Odontogenic Ameloblastomas and Cysts

Tumors and cysts with odontogenic origin represent a family of lesions with specific histo-genetic and clinical characteristics. Among them, ameloblastomas are common benign neoplasms, predominantly detected in the anatomic areas of the jaws and also in the mandible and maxilla. Although they are characterized by a slow and stable growing pattern, a subset of them shows a tendency for local tissue invasiveness and partially increased recurrence rates after surgical excision. Furthermore, heat shock proteins (HSPs) are potentially implicated in ameloblastoma onset and progression. HSPs regulate the folding and refolding of proteins and are induced in response to oxidative stress. They are crucial members of the chaperone intracellular system and are categorized based on their molecular weight (i.e., HSP27, HSP60, HSP70, HSP90). In the current review, we describe HSPs origin and function, focusing on their deregulation mechanisms and impact predominantly on ameloblastomas and also on inflammatory and developmental odontogenic cystic lesions.

A retrospective study on application of fibula/iliac flap surgical techniques to mandibular defects

This study group consists of a total of 61 patients who underwent fibula flap and iliac flap surgeries to repair mandibular defects. Patients' Quality Of life (QOL) at 6 and 24 months after surgery is investigated and compared by the EORTC-QLQ-H&N and OHIP-14. The base data of the two groups of patients are collected and analysed by the SPSS 20.0 statistical software. Independent sample t test was conducted for EORTC-QLQ-H&N and OHIP-14 scores at two time points in each group. The 61 cases of free flap all survived and the difference in the location of the primary tumor between the two groups is statistically significant. The EORTC-QLQ-H&N showed that the score of speech, diet, social contact, and teeth all went up at 6 months after surgery, but went down dramatically at 24 months after surgery. The OHIP-14 showed that there was significant reduction in functional limitation at 24 months after surgery, with statistical significance (p < 0.05) between the groups of iliac flap (19.16 ± 5.33) and fibula flap (33.77 ± 7.71). Therefore, it is suggested that patients suffering from mandibular defects receive surgery utilizing the iliac flap, while those with a larger range of defects or lesions involving the condyle and chin should receive corrective surgery utilizing the fibular flap.

A Rare Case of Deceptive Maxillary Ameloblastoma

Ameloblastoma (AM) is a rare epithelium-derived odontogenic tumor, mostly involving the mandible and less often the maxilla. Most AMs are benign and characterized by indolence and local invasiveness, with a high recurrence rate. Herein, we present a case of maxillary AM in a 42-year-old female suffering from left nasal congestion and facial swelling for almost one month after endoscopic surgery at a local hospital. The mass was completely resected by a transnasal functional endoscopic sinus surgery based on radiographic examination. Subsequently, postsurgical histopathological examinations were conducted, and she was diagnosed with a plexiform AM pattern. Immunohistochemical staining revealed that the tumor was positive for PCK, P63, CK5/6, and CK14 but negative for S100, ER, and Ki67. Based on these findings, the patient was diagnosed with maxillary AM.

CDC7 Expression in Selected Odontogenic Tumors

Objectives. CDC7 is a serine-threonine kinase that plays a key role in initiating DNA replication. It has been implicated in the growth and invasion of many pathologic lesions and suggested as a diagnostic marker. The aim of this study was to evaluate CDC7 in some odontogenic tumors. Materials and Methods. In this cross-sectional study, 45 cases, including 19 ameloblastomas, 15 dentigerous cysts, 7 ameloblastic fibromas, and 4 adenomatoid odontogenic tumors (AOT), were studied immunohistochemically. ANOVA and post hoc methods were used for statistical analysis. Results. CDC7 expression was observed in 93% of tumors and all dentigerous cysts. The expression rate was low. The results showed a higher expression rate of CDC7 in ameloblastoma and ameloblastic fibroma compared to AOT ( $p=0.009$ and $p=0.048$ , respectively). Ameloblastoma and ameloblastic fibroma were not significantly different in CDC7 expression ( $p=0.6$ ). Conclusion. According to the results, the expression of the CDC7 protein in odontogenic tumors is low. The higher expression of CDC7 in ameloblastoma and ameloblastic fibroma in comparison with AOT confirms the hamartomatous growth of the latter, so it can be considered as a potential diagnostic marker. Future studies with a larger sample size are suggested to obtain a cut-off point for diagnostic purposes.

Asymptomatic ameloblastoma of the maxilla with infratemporal fossa involvement: A case report

Introduction and importance

Diagnosis of odontogenic tumors can be challenging due to their rarity and diverse morphology. The clinical diagnosis could be suspected when it had raised near the tooth. But, when their location is not typical, like inside the paranasal sinuses, the diagnosis is less easy. Maxillary ameloblastomas are rare with only sparse information on their epidemiological, histological and effective management.

Case presentation

A 54-year-old woman presented with ameloblastoma of the left maxillary sinus. Intraoral examination revealed partially edentulous with a 2 cm painless ulceration of the left alveolar process of the maxilla. A biopsy was performed which showed a follicular ameloblastoma. The treatment was surgical. She had a combined endoscopic and transoral resection of the tumor. The patient was diagnosed with recurrence within 3 months from surgery.

Discussion

although rarely reported, clinicians should still suspect and know how to manage such as rare and locally invasive tumor as a maxillary ameloblastoma.

Conclusions

As odontogenic tumors are rare, some entities are infrequently encountered, making the diagnosis more difficult. Clinicians, oral and maxillofacial surgeons, and oral pathologists should be familiar with the ameloblastoma and its differential diagnosis for accurate diagnosis and management.

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Ameloblastoma is a benign odontogenic tumor of epithelial origin, with locally aggressive behavior.

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The cases of ameloblastoma in the maxilla jawbone are rare.

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The Management of ameloblastoma is primarily surgical.

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High potential of recurrence

Clinical, Radiographic and Histopathological Analysis of Craniopharyngiomas and Ameloblastomas: A Systematic Review

BACKGROUND

Craniopharyngiomas and ameloblastomas are tumors of epithelial origin, mostly characterized by a benign course, slow growth and for being locally invasive. Some studies highlight the similarity of these neoplasms, especially regarding histopathological aspects. In this context, the aim of the present study was to carry out a systematic literature review correlating the clinical, radiographic, and histopathological aspects of these two tumors.

METHODS

Searches were conducted at the Pubmed, Periódicos Capes, Scopus, Science Direct, Web of Science and Scielo databases, according to the following inclusion criteria: publications in English or Spanish, from the 2000s and 2021, comprising case report studies, case series and literature reviews.

RESULTS

Considering clinical and radiographic aspects, it is evident that craniopharyngiomas and ameloblastomas exhibit few similarities. Histopathologically, however, adamantinomatous craniopharyngiomas are the type of tumor that most resembles ameloblastomas, both concerning the formation of palisade epithelial cords and epithelial formations. Regarding to recurrences in cases of craniopharyngioma, it appears that a more radical surgical resection is more related to a lower recurrence rate for both craniopharyngiomas and ameloblastomas. As for the outcome, it was observed that craniopharyngiomas have a greater relationship with possible systemic disorders.

CONCLUSIONS

This histopathological similarity is related to their origin, since both craniopharyngiomas and ameloblastomas share a relationship with the oral cavity, either partially, as in the case of craniopharyngiomas, or totally, as in ameloblastomas, not comprising the same lesion in different locations. It is important to note that the differential morphogenetic evidence observed herein between these lesions opens up a new field of study aiming at better treatment alternatives in the future.

A retrospective cohort study on predictors associated with skull base invasion of maxillary ameloblastomas

PURPOSE

To identify factors associated with skull base involvement (SBI) of maxillary ameloblastomas (MA).

METHODS

This retrospective cohort study was composed of MA patients treated during a 7-year period. Demographic, radiographic, and nine immunohistopathologic predictor variables were included. The outcome variable was presence of SBI (yes/no). Descriptive, bi- and multivariate statistics were computed, and P ≤ .05 in multivariate analyses was considered statistically significant.

RESULTS

The sample comprised 23 subjects (34.8% females; 21.7% with SBI) with a mean age of 50.3 ± 18.2 years. Candidate predictors of an SBI in MAs were 1) male gender, 2) a low Karnofsky Performance Status score (KPS), 3) multilocular radiolucency, 4) ill-defined margins, 5) cortical perforation, 6) inclusion of an unerupted tooth, 7) moderate to strong reactivity to p53, Ki-67, CD10, astrocyte elevated gene-1 (AEG-1) protein, carbonic anhydrase IX (CA IX), calretinin (calbindin2; CALB2), and BRAF-V600E, and 8) negative to low immunopositivity to α-smooth muscle actin (α-SMA) and syndecan-1 (CD138). However, multivariate analyses confirmed the significant associations of SBI with negative/low syndecan-1 reactivity (P = .003; adjusted odds ratio [OR_adj.], 4.04; 95% confidence interval [95% CI], -.89 to -.48; Pearson's Correlation Coefficient [r] = -.74) and with KPS (P = .003; OR_adj., 4.04; 95% CI, -.78 to -.17; r = -.54) only.

CONCLUSIONS

Our findings suggest an aggressive approach to MAs with negative to low syndecan-1 immunopositivity and/or in multi-morbid patients (who may have difficulty in access to health care). Otherwise, health care inequalities due to low KPS scores should be minimized or eliminated.

Autophagy and immune microenvironment in craniopharyngioma and ameloblastoma

BACKGROUND

Craniopharyngiomas and ameloblastomas show remarkable histologic and molecular similarities. The immune microenvironment of craniopharyngiomas has been recently studied showing interesting findings, while its composition in ameloblastomas is unknown. Similarly, some evidence of autophagic activity, a process of cellular constituents' degradation has been found in ameloblastomas, but no studies exist in craniopharyngiomas. Thus, the aim of the study is to compare factors of the immune microenvironment and the autophagic apparatus between these two tumor types.

METHODS

26 craniopharyngiomas and 14 ameloblastomas were immunohistochemically studied for PD-L1, CD8, CD20, S100, CD163, MECA-79, LC3B and p62.

RESULTS

Craniopharyngiomas showed higher LC3B tumor cell expression, higher CD8+ T cells and higher CD163+ macrophages in comparison to ameloblastomas. LC3B tumor cell expression was associated with overall survival in craniopharyngioma patients and p62 nuclear expression was associated with overall survival in ameloblastoma patients.

CONCLUSION

This is the first study showing the presence of autophagic markers in craniopharyngiomas and describing the immune microenvironment of ameloblastomas.

Left-sided facial mass in an adult female

A left maxillary sinus soft tissue mass was discovered on computed tomography in a 70-year-old woman who had been experiencing blood-tinged mucus for 2 years. The lesion demonstrated mild enhancement, and bony destruction. Magnetic resonance imaging displayed a cerebriform appearance of the mass, which mimicked the appearance of inverted papilloma. However, histology and staining identified the lesion as ameloblastoma. Resection of the tumor was successful with no recurrence 1 month later on follow-up computed tomography. This case represents an unusual imaging presentation of ameloblastoma, and an opportunity to avoid the misdiagnosis of inverted papilloma in similar future cases.

Ameloblastoma with dystrophic calcification: A case report with 3-dimensional cone-beam computed tomographic images of calcification

This report presents a rare case of ameloblastoma with histopathologic and radiographic calcification, including 3-dimensional cone-beam computed tomographic (CBCT) images. A 22-year-old woman had hard swelling on the right mandible. Panoramic and CBCT images showed multilocular radiolucencies with internal calcification foci in the right mandible. Three-dimensional images clearly showed varying-sized radiopacities within the lesion from various angles. A histopathologic examination showed central squamous differentiation and more densely packed peripheral palisading ameloblastic cells. Many areas of keratin pearls and calcifications were also seen. Four previous reports have described 5 cases of ameloblastoma showing histopathologic calcification. This might be the first report to present the calcification of ameloblastoma on panoramic and CBCT images, especially on 3-dimensional images.