Peripheral ameloblastoma (PA) is believed to be the rarest variant of ameloblastoma and only has been described in isolated case reports. PA is usually confined to the soft tissues surrounding the supporting tissues of the teeth. Although it manifests nonaggressive behavior and can be treated with complete removal by local surgical excision, long term follow up is mandatory to prevent future recurrence and possible malignant transformation.

UNASSIGNED: This study identifies factors for differential diagnosis among lesions by retrospectively comparing panoramic and cone-beam computed tomography images and analyzing the characteristics of lesions associated with impacted mandibular third molars (IMTs).
UNASSIGNED: A retrospective cohort study was conducted in patients who simultaneously underwent IMT extraction surgery and related benign tumor resection or cyst enucleation at our institution from 2017 to 2021. To compare the characteristics of each group, two comparative analyses were conducted. The first comparison considered the most frequently observed lesions associated with IMTs: dentigerous cysts, odontogenic keratocysts (OKCs), and ameloblastoma. The second comparison involved placing dentigerous cysts, which have a relatively low recurrence rate, into group A and placing OKC, ameloblastoma, and odontogenic myxoma, which have high recurrence rates, into group B.
UNASSIGNED: Significant differences in the size of the lesion were found in the order of ameloblastoma, OKC, and dentigerous cyst (P <0.05). The buccolingual width of ameloblastoma differed significantly from that of the other groups, with no significant difference observed between the OKCs and dentigerous cysts (P=0.083).
UNASSIGNED: Patient age and lesion size differed significantly among lesion types associated with IMTs, with younger age and larger lesions for OKCs and odontogenic tumors. OKCs are likely to have a larger mesiodistal width than dentigerous cysts. The buccolingual width of ameloblastomas was larger than those of dentigerous cysts and OKCs.

Ameloblastoma, a benign yet aggressive odontogenic tumor known for its recurrence and the severe morbidity from radical surgeries, may benefit from advancements in targeted therapy. We present a case of a 15-year-old girl with ameloblastoma successfully treated with targeted therapy and review the literature with this question: Is anti-MAPK targeted therapy safe and effective for treating ameloblastoma? This systematic review was registered in PROSPERO, adhered to PRISMA guidelines, and searched multiple databases up to December 2023, identifying 13 relevant studies out of 647 records, covering 23 patients treated with MAPK inhibitor therapies. The results were promising as nearly all patients showed a positive treatment response, with four achieving complete radiological remission and others showing substantial reductions in primary, recurrent, and metastatic ameloblastoma sizes. Side effects were mostly mild to moderate. This study presents anti-MAPK therapy as a significant shift from invasive surgical treatments, potentially enhancing life quality and clinical outcomes by offering a less invasive yet effective treatment alternative. This approach could signify a breakthrough in managing this challenging tumor, emphasizing the need for further research into molecular-targeted therapies.

Adenoid ameloblastoma (AA) was recently recognised as a separate tumour type in the most recent World Health Organisation (WHO) classification of head and neck tumours. This decision has been considered controversial by several groups, who have described AA as a subtype of ameloblastoma, a hybrid odontogenic tumour or to fall within the spectrum of other recognised odontogenic tumours, including dentinogenic ghost cell tumour and adenomatoid odontogenic tumour. Here we review the reasons for the WHO decision to classify AA as a separate tumour type. We also critique molecular and histological findings from recent reports published since the WHO classification. While acknowledging that the classification of tumours is constantly evolving, the balance of current evidence suggests that AA should remain a distinct tumour type, and not a subtype of ameloblastoma, pending further molecular characterisation.

UNASSIGNED: Various stemness markers (SOX2, OCT4, and NANOG) have been studied in odontogenic cysts and tumors. However, studies on SALL4 having similar properties of stemness has not been documented. Additionally, insight into fascin as a migratory molecule is less explored. In this study, the expression of SALL4 and fascin were evaluated in ameloblastoma, adenomatoid odontogenic tumor (AOT), odontogenic keratocyst (OKC), dentigerous cyst (DC), radicular cyst (RC), and calcifying odontogenic cyst (COC).
UNASSIGNED: Semi-quantitative analysis of fascin and SALL4 immuno-positive cells was done in a total of 40 cases of ameloblastoma (11 plexiform, 12 follicular, 12 unicystic, and 5 desmoplastic) variants, 6 cases of AOT, 15 each of OKC, DC, RC and 5 of COC. Chi-square test was applied to evaluate the association between SALL4 and fascin expression in odontogenic cysts and tumors.
UNASSIGNED: Fascin immunopositivity was observed in peripheral ameloblast-like cells, and weak or absent in stellate reticulum-like cells. A moderate to weak immune-reactivity to SALL4 was observed in the cytoplasm of ameloblastoma, epithelial cells of dentigerous and radicular cysts, having a marked inflammatory infiltrate, which is an interesting observation. COC and AOT had negative to weak expressions. No recurrence has been reported.
UNASSIGNED: Expression of fascin in ameloblastomas elucidate their role in motility and localized invasion. Its expression in less aggressive lesions like DC, COC, AOT will incite to explore the other functional properties of fascin. SALL4 expression in the cytoplasm of odontogenic cysts and tumors may represent inactive or mutant forms which requires further validation.

Ameloblastic carcinoma is a rare malignant odontogenic tumor that is further classified into being primary or secondary arising from a preexisting benign ameloblastoma. It affects the mandible in two thirds of the patients. There is no standard treatment protocol for this lesion but radicalsurgical excision with or without radiotherapy is reported in the majority of cases. In this paper, we present a case of a 22 year old male diagnosed with Ameloblastic carcinoma of the mandible with a clinical course of typical aggressiveness and extensive destruction. Histopathological examination of the incised biopsy showed a parakeratinized stratified squamous epithelium with underlying fibrous connective tissue stroma. The stroma is highly myxomatous and exhibits islands of odontogenic epithelium and chronic inflammatory cell infiltrates. Interlacing strands of odontogenic epithelium shows stellate reticulum-like cells and occasional areas of squamous metaplasia with cellular and nuclear pleomorphism. In addition, mitotic figures were noted. With the correlation of clinical, radiographic, and histological features, the lesion is diagnosed as ameloblastic carcinoma. The lesion was surgical excised and post-treatment follow-up for 6 months revealed no recurrence of the malignancy.

Ameloblastoma is a non-cancerous but aggressive oral tumor emerging from odontogenic epithelial tissue involved during odontogenesis. Since there is lack in unravelling the complete molecular pathogenesis of ameloblastoma, chemotherapy is less attempted and a lot of disagreement over the optimal treatment option. Hence, till date, wide surgical resection is considered to be the reliable treatment for ameloblastoma. The Neurotrophin Signaling pathway plays an important role in neuron signaling and it is closely related with the MAPK pathway, which on the other hand regulated cell differentiation, apoptosis, proliferation, plasticity and survival. Protein- Protein Interaction analysis was analysed with STRING tool using WNL value, identified that CTNNB1, HRAS, NGFR, NGFR, and SORT1 having high interacting with BDNF, NT4, p75NTR, NGF, and NT3. The results of ontology analysis revealed that Neurotrophin signaling pathway is associated with Cell surface receptor signaling pathway, regulation of cell differentiation, regulation of development process, EGFR tyrosine kinase inhibitor resistance, MAPK signaling pathway, PI3K-Akt signaling pathway and Ras signaling pathway leading to pathogenesis involving genes. Further, clustering coefficient values of proteins BDNF, NT4, p75NTR, NGF & NT3 were identified as 0.627, 0.708, 0.367, 0.644 & 0.415. The results of molecular docking studies revealed among the selected ligands Methyl-ɣ-oresellinate, N-(4-Hydroxy-phenyl)-2-phenyl-N-phenylacetyl-acetamide, Atranorin and Oresellinate exhibited high binding affinity with selected protein. The key genes involved in Neurotrophin signaling pathway leading to ameloblastoma pathogenesis is revealed, which are closely associated with cell differentiation, cell proliferation, pro-apoptosis, and pro-survival regulations. Further it can be concluded that Neurotrophin signaling pathway could be one of the promising pathway to tailor the targeted drug therapy for Ameloblastoma treatment.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s40203-024-00223-2.

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UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: Ameloblastoma is one of the major odontogenic neoplasms with an invasive and recurrence potential. Its tumourigenesis and proliferative capacity can be attributed to the activation or inactivation of certain molecular signalling pathways. Hippo signalling pathway is known to regulate diverse physiological processes related to mitosis and organ growth and is an emerging tumour suppressor pathway, the dysfunction of which is implicated in various diseases including cancers. Yes-associated protein1 (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are the downstream effectors in the Hippo cascade, which on nuclear activation leads to cellular proliferation in various tumours.
UNASSIGNED: The current study was undertaken to evaluate the expression of YAP in various histopathological variants of ameloblastoma and unicystic ameloblastoma.
UNASSIGNED: Fifty formalin-fixed paraffin-embedded tissue samples of histopathologically diagnosed cases of ameloblastoma, and 10 histopathologically diagnosed cases of unicystic ameloblastoma were obtained from the departmental archives to evaluate the immunohistochemical expression of YAP both manually and by software analysis.
UNASSIGNED: More than 90% of cases of conventional ameloblastoma and unicystic ameloblastoma elicited positive expression of YAP. No statistical difference was found among different histopathological variants of conventional ameloblastoma. Significant difference between the means of all four quantitative score groups was observed.
UNASSIGNED: In view of the modulating effect of YAP in tumourigenesis and its higher expression in ameloblastoma, further exploration of this molecule appears to be a promising area of research.