Classical Ameloblastoma Research Articles

Differences in BRAF V600E mutation between the epithelium and mesenchyme in classic ameloblastoma

PurposeLaser capture microdissection (LCM) was used to pinpoint the mutated tissue in ameloblastoma and investigate whether B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutation is the main pathogenic gene in classic ameloblastoma. Study DesignA total of 24 patients with ameloblastoma scheduled to undergo surgery between 2000 and 2024 were included in the study. LCM was used to isolate tumor cells. Oxford nanopore technology (ONT) was used to analyze the collected cells. GO and KEGG enrichment analyses were then performed on the 300 most highly expressed genes in the epithelial tissue and mesenchyme. ResultsMandibular follicular ameloblastoma showed BRAF V600E mutations in all epithelial cells but not in the mesenchyme. The mutation rate was significantly higher in mandibular ameloblastomas compared to the maxilla (p<0.05). RNA-seq showed that traditional follicular ameloblastoma epithelium was enriched in "growth factor receptor binding" and "angiogenesis regulation", while the mesenchyme was enriched in "ECM receptor interaction". KEGG enrichment analysis showed differential gene expression, mainly in MAPK and PI3K-AKT pathways. ConclusionClassical follicular ameloblastoma shows the presence of BRAF V600E mutation in epithelial tissue, with a higher mutation rate in the mandible than in the maxilla. The signaling pathways of MAPK and PI3K may be significantly involved in epithelial signal transduction.

Curettage combined with decompression for the treatment of ameloblastoma in children: report of two cases

BackgroundAmeloblastoma (AM) is the most common benign odontogenic tumor, which is more often detected in the mandible than maxilla, especially the mandibular body and mandibular angle. Pediatric AM is a rare disease, especially in patients aged 10 and younger. Compared with the mainstream osteotomy and reconstructive surgery for adult ameloblastoma, there is more room for discussion in the treatment of pediatric ameloblastoma. The postoperative functional and psychological influence can not be ignored. Especially for children in the period of growth and development, an osteotomy is often challenging to be accepted by their parents. We report two patients with ameloblastoma under 10 years old who are treated with curettage and fenestration, which is a beneficial method for children with ameloblastoma.Case presentationWe present two cases of classic ameloblastoma in children. We describe in detail the patients’ characteristics, treatment processes, and follow-up result. The bone formation and reconstruction in the lesion area after fenestration decompression and curettage are recorded at every clinic review. The surgical details and principles of curettage and decompression are also described and discussed. The two patients have good bone shape recovery and no recurrence.ConclusionsChildren are in the growth and development period and possess an extremely strong ability of bone formation and reconstruction. Based on the principles of minimally invasive and functional preservation, we believe that curettage combined with decompression can be the first choice for treating AM in children, especially for mandibular lesions.

A Modified Surgical Approach for the Treatment of Classic Ameloblastoma in Young Patients

A Modified Surgical Approach for the Treatment of Classic Ameloblastoma in Young Patients

A Modified Surgical Approach for the Treatment of Classic Ameloblastoma in Young Patients

Objective — To analyze the clinical efficacy and application characteristics of the sequence method in the treatment of young patients with large cystic classic ameloblastoma (AM). Methods — 16 young patients with large cystic classic AM treated in the Department of Stomatology of the First Affiliated Hospital of Bengbu Medical College from February 2012 to August 2019 were selected. According to the patient's age, imaging examination, and pathological diagnosis, the sequence method was used for treatment. The patients were followed up regularly after the operation. Results — The patients were followed up for more than 2 years. Of the 16 patients, 13 had no recurrence after fenestration + first curettage, 3 had recurrence after fenestration + first curettage, and 2 had no recurrence after secondary curettage. One patient recurred after repeated curettage and followed up for 10 years and underwent osteotomy. Conclusion — Sequence method can play a good therapeutic effect on young large cystic classic AM.

Observation of the curative effect on curettage combined with fenestration for the treatment of jaw classic ameloblastoma

Observation of the curative effect on curettage combined with fenestration for the treatment of jaw classic ameloblastoma

Extraosseous ameloblastoma of maxillary gingiva: A rare case

Extraosseous ameloblastoma (EA) is a rare odontogenic tumor which comprises about 1% of all ameloblastomas. Extraosseous location is the peculiar feature of this type of tumor, which is otherwise similar to the classical ameloblastoma. The exact etiology of EA is not yet known. The clinical appearance may vary; it presents as a slow-growing, firm, painless mass with a sessile or pedunculated base with a smooth surface. The radiographic findings are nonspecific; diagnosis is based on histopathological features. It poses a diagnostic and therapeutic challenge due to its morphology and biological behavior. This article aims to elucidate rare case of EA of maxillary gingiva in a 40-year-old male patient and also an attempt has been made to discuss its pathogenesis in light of current information from the literature.

Ameloblastic carcinoma of the mandible: A case report

Introduction: Ameloblastic carcinoma is an extremely rare, malignant epithelial tumor of the jaws with a poor prognosis. the most common site of occurrence is the posterior mandible. clinically, it is very aggressive and has potential for extensive local destruction. Majority of the cases arise de novo (primary type), but a few cases arise from a pre-existing ameloblastoma (secondary type). case report: A 30-year-old female presented with a chief complaint of swelling on the left side of the face for the past one year. An incisional biopsy was performed and the histopathology was consistent of ameloblastic carcinoma. On the basis of the histopathology report, left hemimandibulectomy was done taking a safe margin of 2 cm and the defect was reconstructed using titanium reconstruction plate. chemotherapy and radiotherapy were not advised. the patient is under regular follow-up. No recurrence nor metastases reported during the follow-up period. conclusion: Early diagnosis and wide local excision on the primary site is the treatment of choice. the risk of malignant transformation should always be considered when a classic ameloblastoma is diagnosed and the prompt definitive management of an ameloblastoma is essential to eliminate this risk. Finally, meticulous, long-term follow-up is mandatory because recurrence and metastasis in the lung and regional lymph nodes have been reported.

Peripheral Ameloblastoma: A Case Report and Review of Literature

Peripheral ameloblastoma, a rare and unusual variant of odontogenic tumour, comprises about 2–10% of all ameloblastomas. The extraosseous location is the peculiar feature of this type of tumour, which is otherwise similar to the classical ameloblastoma. This paper describes a case of peripheral ameloblastoma in a 67-year-old female affecting the lingual alveolar mucosa of the mandibular 32–34 region which was clinically diagnosed as pyogenic granuloma. This paper becomes important due to availability of all data, makeing it a well-documented case.

PERIPHERAL AMELOBLASTOMA - A CASE REPORT WITH EMPHASIS ON ETIOPATHOGENESIS

Peripheral ameloblastoma, a rare and unusual variant of odontogenic tumour, comprises about 1% of all ameloblastomas. The extraosseous location is the peculiar feature of this type of tumour, which is otherwise similar to the classical ameloblastoma. It appears in the gingiva and oral mucosa and it usually does not show any bone involvement on radiographs, except for saucer shaped erosion of underlying alveolar bone. Recurrence is considered uncommon. We report a case of peripheral ameloblastoma of maxillary gingiva.

Desmoplastic ameloblastoma of anterior mandible: Case report of a rarity

Ameloblastoma, one of the most common odontogenic tumors of the jaws, presents classical clinical, radiographic and histopathological diagnostic features exhibiting a benign but locally aggressive and destructive clinical course with a high rate of recurrence. A case of desmoplastic ameloblastoma of mandible is discussed in this article, which presents itself as a rare variant of ameloblastoma with unusual inconclusive clinico-radiographic features to be diagnosed as classical ameloblastoma and difficult to differentiate from other suspected multilocular benign odontogenic or reactive lesions of the jaws. It is the typical histopathological picture of the lesion exhibiting a blend of desmoplasia (collagenization) and ameloblastoma that leads to its final diagnosis and determines its management.

Peripheral ameloblastoma: a case report

Peripheral ameloblastoma, a rare and unusual variant of odontogenic tumour, comprises about 1% of all ameloblastomas. The extraosseous location is the peculiar feature of this type of tumour, which is otherwise similar to the classical ameloblastoma. An additional case of this infrequent tumour is described on the lingual alveolar mucosa of the right mandibular premolar region in a 60-year-old man. Clinical evidence, microscopic findings, CT imaging and recurrence for this tumour are discussed.

Expression of nuclear factor-kappaB, Ki-67 and matrix metalloproteinase-9 in calcifying odontogenic cyst

To evaluate the expression of nuclear factor-kappaB (NF-kappaB), Ki-67 and matrix metalloproteinase-9 (MMP-9) in calcifying odontogenic cyst (COC), in order to investigate the proliferation and invasion of COC. Twenty-six cases of COC were classified into calcifying cystic odontogenic tumor (CCOT), dentinogenic ghost cell tumor (DGCT) and ghost cell odontogenic carcinoma (GCOC) based on the WHO classification of odontogenic tumors in 2005. The specimens of COC and 10 classic ameloblastoma (AB) were examined immunohistochemically to determine the expression of NF-kappaB p65, Ki-67 and MMP-9. NF-kappaB was mainly detected in the cytoplasm of most tumor cells, but was only detected in the nucleus of few tumor cells (rate of nuclear staining < 1%). The expression of Ki-67 was significantly higher in GCOC than in CCOT (P < 0.001), DGCT (P < 0.05) and AB (P < 0.005). MMP-9 was detected both in tumor cells and stromal cells. GCOC showed significantly higher percentage of MMP-9 positive cases in stromal cells than CCOT, DGCT and AB (P < 0.05). NF-kappaB may minimally affect the progression and invasion of COC. GCOC shows significantly higher proliferative activity and aggressiveness than CCOT and DGCT. MMP-9 in stroma may play a key role in the invasion of GCOC.

Desmoplastic variant of ameloblastoma in Chinese patients

Desmoplastic ameloblastoma is a rare tumour, and we know of only 43 previously reported cases. We report seven Chinese patients (five men and two women) with the desmoplastic variant of ameloblastoma, which makes up 9% of all ameloblastomas diagnosed during the years 1981–1995. The age ranged from 18 to 68 years (mean 43). Five of the tumours were in the maxilla and two were in the mandible. Five of them were situated anteriorly, the remaining two cases involving both anterior and posterior maxilla. The features of the 42 cases previously reported were reviewed and were compared with those in the present study. Our results differ in that we found a male predominance, wider age range and more tumours in the maxilla. Histologically, this variant of ameloblastoma is characterized by abundant collagenous stroma. Because the epithelial clusters may show prominent squamous metaplasia or may be compressed into thin strands in most areas, the appearance may mimic a squamous odontogenic tumour or odontogenic fibroma. The behaviour of this variant of ameloblastoma is likely to be the same as that of the classic ameloblastoma.

Ameloblastic carcinoma of the jaws: A report of two cases

Two cases of ameloblastic carcinoma of the jaws are reported. Histopathologically, the lesions showed cytologic features of malignancy in addition to classical ameloblastoma patterns and were therefore documented as examples of ameloblastic carcinoma. The negative cytokeratin expression by the malignant cells on histochemical analysis is notably different from that normally observed in classical ameloblastomas.

Ameloblastomas with pronounced desmoplasia

Ameloblastomas are uncommon epithelial tumors of the jaws comprising approximately 1% of all odontogenic cysts and tumors.’ Although most are microscopically benign and lack cytologic atypia, they are generally considered to be locally aggressive and destructive, exhibiting a high rate of recurrence. In spite of its apparent rarity, several large series describing a thorough clinical statistical analysis have been reported.‘,2 Over 80% of all ameloblastomas occur in the mandible, the vast majority being located in the molar-ramus region. The average age of patients is approximately 39 years, and there is essentially no sex prediliction. Radiographically, the ameloblastoma may vary in size and configuration from a small, well-circumscribed unilocular radiolucency to a large multilocular radiolucency. Many are associated with unerupted teeth and resemble dentigerous cysts. The most common clinical finding is a nontender enlargement that, in spite of a relatively slow rate of growth, may reach enormous size.3 Microscopically, the classic ameloblastoma consists of islands, nests, and cords of odontogenic epithelium rimmed by columnar cells resembling ameloblasts. The center of these epithelial structures contains loosely arranged spindleor stellateshaped cells resembling the stellate reticulum of a developing tooth. The surrounding fibrous connective tissue stroma is composed of mature collagen.