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Gan To Kagaku Ryoho. Cancer &... May 2000Ameloblastoma is a histologically benign tumor derived from odontogenic apparatus. The tumor can infiltrate into surrounding tissues. Although it is benign, it presents...
Ameloblastoma is a histologically benign tumor derived from odontogenic apparatus. The tumor can infiltrate into surrounding tissues. Although it is benign, it presents symptoms of a malignant tumor, such as infiltration into the lungs, pleura, regional and distant metastases, orbit, base of skull, brain and has resulted in death. It also has a high incidence of recurrences, the existence of regional or distant metastasis, showing a microscopic pattern of ameloblastic carcinoma with cytologic features of an increasing nuclear/cytoplastic ratio, nuclear hyperchromatism, and the presence of mitosis. We report a study of 12 patients of ameloblastoma of the jaws between January 1992 and December 1996 consisting of 8 affected in the mandible and 4 in the maxilla. One patient with a tumor in the maxilla was excluded from this study, due to a different histological and clinical behaviour of the ameloblastoma.
Topics: Adult; Ameloblastoma; Combined Modality Therapy; Humans; Male; Mandible; Mandibular Neoplasms; Maxilla; Maxillary Neoplasms; Neoplasm Recurrence, Local; Prognosis
PubMed: 10895162
DOI: No ID Found -
Medicina (Kaunas, Lithuania) Dec 2023Ameloblastoma is a benign epithelial tumor that has aggressive, destructive and unlimited growth potential, having the capacity for recurrence and malignant...
Ameloblastoma is a benign epithelial tumor that has aggressive, destructive and unlimited growth potential, having the capacity for recurrence and malignant transformation. Regarding the symptoms and clinical signs, the presentation of ameloblastoma is poor. In children and young people, ameloblastoma can be difficult to diagnose, because it mimics other benign lesions. Its diagnosis requires a combination of imaging data, histopathological analysis and molecular tests. The methods of treatment consist of radical surgery (segmental resection) and conservative treatments (enucleation with bone curettage). The particularity of the presented case is represented by the late request for medical consultation, a direct consequence of the measures implemented to prevent and control the spread of COVID-19.
Topics: Child; Female; Humans; Adolescent; Ameloblastoma; Mandible; Aggression; COVID-19; Conservative Treatment
PubMed: 38256328
DOI: 10.3390/medicina60010066 -
Journal of Oral Pathology & Medicine :... Apr 2023The advances in molecular technologies have allowed a better understanding of the molecular basis of odontogenic cysts and tumours. PTCH1 mutations have been reported in... (Review)
Review
The advances in molecular technologies have allowed a better understanding of the molecular basis of odontogenic cysts and tumours. PTCH1 mutations have been reported in a high proportion of odontogenic keratocyst. BRAF p.V600E are recurrent in ameloblastoma and KRAS p.G12V/R in adenomatoid odontogenic tumour, dysregulating the MAPK/ERK pathway. Notably, BRAF p.V600E is also detected in ameloblastic carcinoma, but at a lower frequency than in its benign counterpart ameloblastoma. Recently, adenoid ameloblastoma has been shown to be BRAF wild-type and to harbour CTNNB1 (β-catenin gene) mutations, further suggesting that it is not an ameloblastoma subtype. CTNNB1 mutations also occur in other ghost-cell-containing tumours, including calcifying odontogenic cysts, dentinogenic ghost cell tumours and odontogenic carcinoma with dentinoid, but the link between CTNNB1 mutations and ghost cell formation in these lesions remains unclear. Regarding mixed tumours, BRAF p.V600E has been reported in a subset of ameloblastic fibromas, ameloblastic-fibrodentinomas and fibro-odontomas, in addition to ameloblastic fibrosarcoma. Such mutation-positivity in a subset of samples can be helpful in differentiating some of these lesions from odontoma, which is BRAF-wild-type. Recently, FOS rearrangements have been reported in cementoblastoma, supporting its relationship with osteoblastoma. Collectively, the identification of recurrent mutations in these aforementioned lesions has helped to clarify their molecular basis and to better understand the interrelationships between some tumours, but none of these genetic abnormalities is diagnostic. Since the functional effect of pathogenic mutations is context and tissue-dependent, a clear role for the reported mutations in odontogenic cysts and tumours in their pathogenesis remains to be elucidated.
Topics: Humans; Ameloblastoma; Proto-Oncogene Proteins B-raf; Odontogenic Tumors; Odontogenic Cysts; Odontoma; Mouth Neoplasms; Carcinoma
PubMed: 36629457
DOI: 10.1111/jop.13401 -
The American Journal of Case Reports Jul 2015Ameloblastic carcinoma secondary type is an extremely rare and aggressive odontogenic neoplasm that exhibits histological features of malignancy in primary and...
BACKGROUND
Ameloblastic carcinoma secondary type is an extremely rare and aggressive odontogenic neoplasm that exhibits histological features of malignancy in primary and metastatic sites. It arises through carcinomatous de-differentiation of a pre-existing ameloblastoma or odontogenic cyst, typically following repeated treatments and recurrences of the benign precursor neoplasm. Identification of an ameloblastic carcinoma, secondary type presenting with histologic features of malignant transformation from an earlier untreated benign lesion remains a rarity. Herein, we report 1 such case.
CASE REPORT
A 66-year-old man was referred for management of a newly diagnosed ameloblastic carcinoma. He underwent radical surgical intervention comprising hemimandibulectomy, supraomohyoid neck dissection, and free-flap reconstruction. Final histologic analysis demonstrated features suggestive of carcinomatous de-differentiation for a consensus diagnosis of ameloblastic carcinoma, secondary type (de-differentiated) intraosseous.
CONCLUSIONS
Ameloblastic carcinoma, secondary type represents a rare and challenging histologic diagnosis. Radical surgical resection with adequate hard and soft tissue margins is essential for curative management of localized disease.
Topics: Aged; Ameloblastoma; Biopsy; Diagnosis, Differential; Humans; Lymphatic Metastasis; Male; Mandibular Neoplasms; Mandibular Osteotomy; Neck Dissection; Radiography, Panoramic
PubMed: 26126621
DOI: 10.12659/AJCR.893918 -
Scientific Reports Aug 2016Ameloblastoma is a locally invasive benign neoplasm derived from odontogenic epithelium and presents with diverse phenotypes yet to be characterized molecularly. High...
Ameloblastoma is a locally invasive benign neoplasm derived from odontogenic epithelium and presents with diverse phenotypes yet to be characterized molecularly. High recurrence rates of 50-80% with conservative treatment in some sub-types warrants radical surgical resections resulting in high morbidity. The objective of the study was to characterize the transcriptome of ameloblastoma and identify relevant genes and molecular pathways using normal odontogenic tissue (human "dentome") for comparison. Laser capture microdissection was used to obtain neoplastic epithelial tissue from 17 tumors which were examined using the Agilent 44 k whole genome microarray. Ameloblastoma separated into 2 distinct molecular clusters that were associated with pre-secretory ameloblast and odontoblast. Within the pre-secretory cluster, 9/10 of samples were of the follicular type while 6/7 of the samples in the odontoblast cluster were of the plexiform type (p < 0.05). Common pathways altered in both clusters included cell-cycle regulation, inflammatory and MAPkinase pathways, specifically known cancer-driving genes such as TP53 and members of the MAPkinase pathways. The pre-secretory ameloblast cluster exhibited higher activation of inflammatory pathways while the odontoblast cluster showed greater disturbances in transcription regulators. Our results are suggestive of underlying inter-tumor molecular heterogeneity of ameloblastoma sub-types and have implications for the use of tailored treatment.
Topics: Ameloblastoma; Cluster Analysis; Humans; Laser Capture Microdissection; Mitogen-Activated Protein Kinases; Odontoblasts; Odontogenic Tumors; Oligonucleotide Array Sequence Analysis; Phenotype; RNA, Neoplasm; Transcriptome; Tumor Suppressor Protein p53
PubMed: 27491308
DOI: 10.1038/srep30867 -
BMJ Case Reports Apr 2019Ameloblastoma a benign neoplasm of the maxillofacial region has been divided into various histopathological types by WHO. A more complex and confusing type includes...
Ameloblastoma a benign neoplasm of the maxillofacial region has been divided into various histopathological types by WHO. A more complex and confusing type includes hybrid type, which as the name suggest include more than two variants mostly histopathological. Various authors have reported cases of this type but the exact histopathological features are still unclear and each case that is being reported add to the literature, which further strengthens its histopathological feature. Also, this is a lesion whose clinical and radiographical features are similar to all the variants and a definitive diagnosis is achieved by histopathology only. Here, we present a case of hybrid ameloblastoma with striking and unique histopathological features.
Topics: Ameloblastoma; Diagnosis, Differential; Edema; Humans; Male; Mandibular Neoplasms; Young Adult
PubMed: 30975786
DOI: 10.1136/bcr-2019-229834 -
International Journal of Oral Science Feb 2024Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms...
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.
Topics: Humans; Ameloblastoma; Neoplasm Recurrence, Local; Phenotype; Cell Transformation, Neoplastic; Gene Expression Profiling
PubMed: 38424060
DOI: 10.1038/s41368-024-00281-4 -
Modern Pathology : An Official Journal... Nov 2022Ameloblastoma is a benign, locally aggressive odontogenic neoplasm with variable solid and cystic morphology. On account of its histologic variety, diagnostically...
Ameloblastoma is a benign, locally aggressive odontogenic neoplasm with variable solid and cystic morphology. On account of its histologic variety, diagnostically challenging cases can bear resemblance to odontogenic keratocyst/keratocystic odontogenic tumor (KCOT) or dentigerous cyst (DC). BRAF mutation has been reported to be specific for and frequent in ameloblastoma, and this study evaluated the usefulness of immunohistochemistry (IHC) using the BRAF VE1 mutant-specific antibody as a diagnostic adjunct in this setting. We investigated 46 ameloblastomas, 30 KCOTs, and 30 DCs. BRAF VE1 IHC was performed on all cases and allele-specific polymerase chain reaction (AS-PCR) for BRAF mutation was performed on 30 ameloblastomas and any IHC-positive KCOT/DC. BRAF VE1 IHC was positive in 31/37 (83.8%) mandibular ameloblastomas but not in any maxillary ameloblastomas (0/9), KCOT (0/30), or DC (0/30). Equivocal staining was seen in 1/37 (3.3%) mandibular ameloblastomas. Of the 30 ameloblastomas subjected to AS-PCR, BRAF mutation was identified in 19/23 (82.6%) mandibular ameloblastomas and 0/7 (0.0%) maxillary ameloblastomas. BRAF mutant ameloblastomas were positive by IHC in 18/19 (94.7%) cases and equivocal in 1/19 (5.3%) cases. All 11 (100.0%) BRAF-wild type ameloblastomas were negative by IHC. BRAF VE1 is an excellent tool for the diagnosis of mandibular ameloblastoma but of limited utility in the maxilla, where it less commonly occurs and where BRAF mutation is considerably less frequent.
Topics: Humans; Ameloblastoma; Immunohistochemistry; Proto-Oncogene Proteins B-raf; Biomarkers, Tumor; Mutation; Odontogenic Tumors
PubMed: 35676332
DOI: 10.1038/s41379-022-01105-8 -
Journal of Stomatology, Oral and... Nov 2022Ameloblastoma is a benign odontogenic tumor with high recurrence rate. It can cause severe abnormalities of the face and jaw, leading to severe disfiguration and... (Review)
Review
Ameloblastoma is a benign odontogenic tumor with high recurrence rate. It can cause severe abnormalities of the face and jaw, leading to severe disfiguration and impaired jaw and airway functions. Wide local excision and reconstruction are required for ameloblastoma. Recurrence in the free bone graft is rare, especially in the fibula free flap. A 67-year-old man had a history of ameloblastoma of the left mandible resected 16 years ago with reconstruction using the fibula free flap. Three years ago, radiologic examination suggested a possible tumor recurrence in the fibula free flap. Because of the left facial swelling with hard, painless, and elastic tumor extending in the mandibular, he was admitted to the hospital and underwent segmental mandibulectomy. Ameloblastoma in the fibula was confirmed by pathological examination meanwhile not invasion in soft tissue nor bone margin. At the 24-month follow-up, no recurrence was detected. As the strong tendency for recurrence, especially in cases of large tumor size and soft tissue involvement, the radical resection and long-term follow-up are recommended.
Topics: Male; Humans; Aged; Ameloblastoma; Free Tissue Flaps; Mandibular Neoplasms; Plastic Surgery Procedures; Fibula
PubMed: 35697254
DOI: 10.1016/j.jormas.2022.06.007 -
The Journal of Craniofacial Surgery May 2022Aggressive benign mandibular tumors are uncommon in the pediatric population, and there is few publishing in the literature specifically dealing with them. Aggressive...
INTRODUCTION
Aggressive benign mandibular tumors are uncommon in the pediatric population, and there is few publishing in the literature specifically dealing with them. Aggressive tumors can be defined based on known biologic behavior and/or histologic type and/or clinical characteristics.
AIM OF THE STUDY
To review the clinical features and management of lower jaw pediatric aggressive benign tumor.
PATIENTS AND METHODS
Medical records review of pediatric patients presented with aggressive benign mandibular tumors to the Maxillofacial and Plastic Surgery Department, University of Alexandria, Egypt between 2011 and 2019.
RESULTS
Fifty-eight patients were included in this study, aged between 2 and 16 years (average = 11.8). Ameloblastoma was the commonest pathological diagnosis (n = 18) followed by central giant cell granuloma (n = 11) and juvenile ossifying fibroma (n = 10). Patients with central giant cell granuloma were treated by en-block resection (n = 4) or curettage after interferon alfa injection (n = 7). All other benign tumors were treated by en-block resection. The length of follow-up ranged from 1 to 8 years. Successful reconstruction was accomplished in 45 patients (88.2%).
CONCLUSIONS
Aggressive lesion should be treated in an aggressive manner and immediate reconstruction is advocated. However, pharmacotherapy combined with enucleation is a more conservative approach for management of aggressive central giant cell tumors.
Topics: Adolescent; Ameloblastoma; Child; Child, Preschool; Curettage; Granuloma, Giant Cell; Humans; Mandible; Mandibular Neoplasms
PubMed: 34387270
DOI: 10.1097/SCS.0000000000008085