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Calcified Tissue International Apr 2024Ameloblastoma is a rare odontogenic tumor which may be complicated by hypercalcemia in advanced disease. Tumoral parathyroid hormone-related peptide (PTHrP) production...
Ameloblastoma is a rare odontogenic tumor which may be complicated by hypercalcemia in advanced disease. Tumoral parathyroid hormone-related peptide (PTHrP) production and local osteolysis from paracrine factors have been proposed as mechanisms. Mitogen-activated protein kinase (MAPK) inhibitors have been successfully used in ameloblastomas with BRAF V600E mutation to reduce symptoms and decrease tumor burden. Serum calcium has been observed to normalize following treatment with MAPK inhibitors; however, the response of PTHrP and markers of bone turnover has not been reported. We describe a case of a 55-year-old female with PTHrP-mediated hypercalcemia secondary to BRAF V600E-positive ameloblastoma with pulmonary metastases. Following treatment with dabrafenib and trametinib, the patient experienced the regression of pulmonary lesions and normalization of serum calcium, PTHrP, and markers of bone turnover. Tissue samples of ameloblastoma carrying BRAF V600E mutation are more likely to express PTHrP than tissue samples carrying wild-type BRAF. In our case, resolution of PTHrP-mediated hypercalcemia following initiation of BRAF/MEK inhibition provides additional evidence that the MAPK pathway contributes to PTHrP synthesis. It also raises the question of whether MAPK inhibitors would be effective in treating PTHrP-mediated hypercalcemia associated with other malignancies harboring BRAF V600E mutation.
Topics: Female; Humans; Middle Aged; Parathyroid Hormone-Related Protein; Hypercalcemia; Ameloblastoma; Proto-Oncogene Proteins B-raf; Calcium; Mitogen-Activated Protein Kinase Kinases; Mutation
PubMed: 38252285
DOI: 10.1007/s00223-023-01177-x -
Journal of Oral Pathology & Medicine :... Feb 2024The purpose of the current study was to report on the clinical presentation and radiologic features of 155 cases of ameloblastoma (AB), representing a detailed, large,...
BACKGROUND
The purpose of the current study was to report on the clinical presentation and radiologic features of 155 cases of ameloblastoma (AB), representing a detailed, large, single-centre radiologic study.
METHODS
Histologically confirmed cases were reviewed over 11 years. Demographic and clinical data were retrieved from the patient's records. Radiologic information was analysed from available radiographs. The radiologic features of ABs were assessed according to the mean age of presentation and the mean duration of the lesion. The distinguishing radiologic features between adults/children and sex were also evaluated.
RESULTS
A statistically significant correlation existed between loss of border demarcation and advanced mean age. Multilocular lesions were markedly more common in adults compared to children. Multilocular ABs were associated with increased lesion duration and advanced mean age. Radiologic signs of reactive bony changes associated with the tumour presented at the highest mean duration of all bony effects. Bony expansion and cortical destruction were statistically correlated with lesion duration. Tooth impaction was more common in children. Some mandibular lesions reached a significant size, resulting in impingement of the maxillary sinus, zygoma, orbit and pterygoid plates.
CONCLUSION
Due to unfortunate healthcare access constraints, ABs grow to significant sizes and exhibit features not often reported in the literature. The findings of this analysis highlighted the radiologic features of ABs expressed through the mean age and duration of the lesion. This emphasises the significance of timely management of these lesions.
Topics: Adult; Child; Humans; Ameloblastoma; Mandibular Neoplasms; Maxillary Neoplasms; Radiography
PubMed: 38212674
DOI: 10.1111/jop.13510 -
BMC Oral Health Jan 2024Ameloblastoma, a common benign tumor found in the jaw bone, necessitates accurate localization and segmentation for effective diagnosis and treatment. However, the...
BACKGROUND
Ameloblastoma, a common benign tumor found in the jaw bone, necessitates accurate localization and segmentation for effective diagnosis and treatment. However, the traditional manual segmentation method is plagued with inefficiencies and drawbacks. Hence, the implementation of an AI-based automatic segmentation approach is crucial to enhance clinical diagnosis and treatment procedures.
METHODS
We collected CT images from 79 patients diagnosed with ameloblastoma and employed a deep learning neural network model for training and testing purposes. Specifically, we utilized the Mask R-CNN neural network structure and implemented image preprocessing and enhancement techniques. During the testing phase, cross-validation methods were employed for evaluation, and the experimental results were verified using an external validation set. Finally, we obtained an additional dataset comprising 200 CT images of ameloblastoma from a different dental center to evaluate the model's generalization performance.
RESULTS
During extensive testing and evaluation, our model successfully demonstrated the capability to automatically segment ameloblastoma. The DICE index achieved an impressive value of 0.874. Moreover, when the IoU threshold ranged from 0.5 to 0.95, the model's AP was 0.741. For a specific IoU threshold of 0.5, the model achieved an AP of 0.914, and for another IoU threshold of 0.75, the AP was 0.826. Our validation using external data confirms the model's strong generalization performance.
CONCLUSION
In this study, we successfully applied a neural network model based on deep learning that effectively performs automatic segmentation of ameloblastoma. The proposed method offers notable advantages in terms of efficiency, accuracy, and speed, rendering it a promising tool for clinical diagnosis and treatment.
Topics: Humans; Ameloblastoma; Deep Learning; Research Design; Tomography, X-Ray Computed
PubMed: 38195496
DOI: 10.1186/s12903-023-03587-7 -
Journal of Oral Pathology & Medicine :... Jan 2024Ameloblastoma is an aggressively growing, highly recurrent odontogenic jaw tumor. Its association with BRAFV600E mutation is an indication for BRAFV00E-inhibitor therapy...
BACKGROUND
Ameloblastoma is an aggressively growing, highly recurrent odontogenic jaw tumor. Its association with BRAFV600E mutation is an indication for BRAFV00E-inhibitor therapy The study objective was to identify a sensitive low-cost test for BRAFV600E-positive ameloblastoma. We hypothesized that immunohistochemical staining of formalin-fixed paraffin-embedded tissues for BRAFV600E mutation is a low-cost surrogate for BRAFV600E gene sequencing when laboratory resources are inadequate for molecular testing.
METHODS
Tissues from 40 ameloblastoma samples were retrieved from either formalin-fixed paraffin-embedded blocks, RNAlater™ stabilization solution or samples inadvertently pre-fixed in formalin before transfer to RNAlater™. BRAFV600E mutation was assessed by Direct Sanger sequencing, Amplification Refractory Mutation System-PCR and immunohistochemistry (IHC).
RESULTS
BRAFV600E mutation was detected by IHC, Amplification Refractory Mutation System-PCR and Direct Sanger sequencing in 93.33%, 52.5% and 30% of samples respectively. Considering Direct Sanger sequencing as standard BRAFV600E detection method, there was significant difference between the three detection methods (𝜒 (2) = 31.34, p < 0.0001). Sensitivity and specificity of IHC were 0.8 (95% CI: 0.64-0.90) and 0.9 (95% CI: 0.75-0.99) respectively, while positive predictive value and negative predictive value (NPV) were 0.9 and 0.8 (Fischer's test, p < 0.0001) respectively. Sensitivity and specificity of Amplification Refractory Mutation System-PCR detection method were 0.7 (95% CI: 0.53-0.80) and 0.9 (95% CI = 0.67-0.98) respectively, while PPV and NPV were 0.9 and 0.6 respectively (Fischer's test, p < 0.0001).
CONCLUSION
Low-cost and less vulnerability of IHC to tissue quality make it a viable surrogate test for BRAFV600E detection in ameloblastoma. Sequential dual IHC and molecular testing for BRAFV600E will reduce equivocal results that could exclude some patients from BRAFV600E-inhibitor therapies.
Topics: Humans; Ameloblastoma; Proto-Oncogene Proteins B-raf; Mutation; Odontogenic Tumors; Formaldehyde
PubMed: 38185471
DOI: 10.1111/jop.13506 -
Oral Radiology Apr 2024Dentigerous cysts are known as the second most common type of cyst in the jaws. The cyst is one of the lesions occurred frequently in the posterior body of the mandible...
Dentigerous cysts are known as the second most common type of cyst in the jaws. The cyst is one of the lesions occurred frequently in the posterior body of the mandible and is often related to the unerupted third molar and forms around the crown of the unerupted tooth attaching at the cementoenamel junction. Such characteristic appearances are the diagnostic points differentiating from ameloblastoma or odontogenic keratocyst. However, it would be hard for us to diagnose it as a dentigerous cyst if the lesion does not show its typical appearance. We experienced two cases of dentigerous cysts which did not form around the crown of the unerupted tooth on radiologically. Both cysts were relatively large and resorbed adjacent teeth roots. Therefore, an ameloblastoma or an odontogenic keratocyst was suspected rather than a dentigerous cyst as the imaging diagnosis. The biopsy revealed that the lesion was a "dentigerous cyst" in one of the cases and "developmental cyst with inflammation" in another case. After the excision, the histopathological diagnosis was a dentigerous cyst with inflammation in both cases. This report shows the two cases of dentigerous cysts focusing on panoramic radiography and CT images. Also, we discuss the differential diagnosis by reconsidering those diagnostic points.
Topics: Humans; Dentigerous Cyst; Tooth, Unerupted; Ameloblastoma; Radiography, Panoramic; Odontogenic Cysts; Inflammation; Tomography, X-Ray Computed
PubMed: 38165531
DOI: 10.1007/s11282-023-00732-4 -
Journal of Oral Pathology & Medicine :... Jan 2024Ameloblastoma and ameloblastic carcinoma are epithelial odontogenic tumors that can be morphologically similar. In the present study, we evaluated the DNA content and...
BACKGROUND
Ameloblastoma and ameloblastic carcinoma are epithelial odontogenic tumors that can be morphologically similar. In the present study, we evaluated the DNA content and Ki-67 index in the two tumors.
METHODS
The paraffin blocks of the tumors were selected to obtain sections for the immunohistochemical reactions and preparation of the cell suspension for acquisition in a flow cytometer. The Random Forest package of the R software was used to verify the contribution of each variable to classify lesions into ameloblastoma or ameloblastic carcinoma.
RESULTS
Thirty-two ameloblastoma and five ameloblastic carcinoma were included in the study. In our sample, we did not find statistically significant differences in Ki-67 labeling rates. A higher fraction of cells in 2c (G1) was correlated with the diagnosis of ameloblastoma, whereas higher rates of 5c-exceeding rate (5cER) were correlated with ameloblastic carcinoma. The Random Forest model highlighted histopathological findings and parameters of DNA ploidy study as important features for distinguishing ameloblastoma from ameloblastic carcinoma.
CONCLUSION
Our findings suggest that the parameters of the DNA ploidy study can be ancillary tools in the classification of ameloblastoma and ameloblastic carcinoma.
Topics: Humans; Ameloblastoma; Ki-67 Antigen; Odontogenic Tumors; Carcinoma; Ploidies; DNA
PubMed: 38163857
DOI: 10.1111/jop.13505 -
Cureus Nov 2023Ameloblastoma is a benign yet locally aggressive tumor of the jaw bones and is most commonly found in the lower mandibular region. Histologically, it shows benign...
Ameloblastoma is a benign yet locally aggressive tumor of the jaw bones and is most commonly found in the lower mandibular region. Histologically, it shows benign characteristics. However, ameloblastoma can turn malignant to show a more aggressive clinical course. Carcinoma ex ameloblastoma is an extremely rare malignancy arising from a pre-existing long-standing ameloblastoma or a recurrence of an ameloblastoma. According to the literature search, six to seven cases have so far been documented, and the majority of the lesions had a propensity to metastasize. Here, we present a case of carcinoma ex ameloblastoma implicating a 19-year-old male patient manifesting in the mandible, which arises from pre-existing ameloblastoma.
PubMed: 38156168
DOI: 10.7759/cureus.49536 -
Oral Surgery, Oral Medicine, Oral... Apr 2024Peripheral ameloblastoma (PA) is a rare variant of ameloblastoma that presents as a slow-growing, painless mass in the gingival tissues or alveolar mucosa. It shares...
Peripheral ameloblastoma (PA) is a rare variant of ameloblastoma that presents as a slow-growing, painless mass in the gingival tissues or alveolar mucosa. It shares histologic features with conventional ameloblastoma but is less invasive and aggressive. This case report describes a 51-year-old female with a PA that simultaneously or subsequently developed underlying squamous cell papilloma after mandibular third molar extraction. Clinical examination revealed a pedunculated gingival lesion mimicking squamous cell papilloma. Histopathologic examination confirmed PA underlying squamous cell papilloma after an excisional biopsy. Imaging revealed mild bone resorption, leading to a further soft tissue excision and minimal osteoectomy to rule out intraosseous involvement. The patient remained asymptomatic without signs of recurrence in the 1-year follow-up. PA diagnosis can be challenging due to its clinical resemblance to other gingival lesions and histopathologic features. Treatment typically involves surgical excision, with long-term follow-up recommended due to possible recurrence and malignant transformation.
Topics: Female; Humans; Middle Aged; Ameloblastoma; Molar, Third; Diagnosis, Differential; Papilloma; Biopsy
PubMed: 38155004
DOI: 10.1016/j.oooo.2023.09.005 -
Oral Oncology Feb 2024
Topics: Humans; Ameloblastoma; Liquid Biopsy; Polymerase Chain Reaction; Mutation; Proto-Oncogene Proteins B-raf
PubMed: 38147740
DOI: 10.1016/j.oraloncology.2023.106666 -
Annali Italiani Di Chirurgia Dec 2023Ameloblastoma is a borderline bone tumor that origins from the residual epithelium of the teeth germs, the epithelium of the enamel organ or the epithelium of... (Review)
Review
INTRODUCTION
Ameloblastoma is a borderline bone tumor that origins from the residual epithelium of the teeth germs, the epithelium of the enamel organ or the epithelium of odontogenic cysts. Ameloblastoma management is challenging owing to the necessity of tumor radical excision and the functional and aesthetic reconstruction of the surgical defect. The fibula-free flap (FFF) provides a high-quality and predictable mandibular reconstruction due to the high-caliber vascular pedicle, the bone length that can reconstruct large defects, the possibility for implants-based prosthetic reconstruction, and the possibility of harvesting a composite flap that can replace the mucosa, hence protecting the underlying bone reconstruction.
CASE REPORTS
We report adult female and elder male patients, who were addressed to our hospital for mandible swelling and histopathological results of ameloblastoma. The lesions were treated by segmental mandibulectomy and FFF reconstructions. Osteosynthesis plates and screws were enough for the female patient's reconstruction of the lateral mandible defect and a load-bearing plate was necessary for the male patient's reconstruction of the surgical defect that included the anterior part of the mandible. The facial artery was used in both cases, and the surgeries lasted approximately 8 hours. No recurrence was observed at the follow-up and the aesthetic function was well re-established.
CONCLUSION
Radical treatment of ameloblastoma is mandatory. The aesthetic function could be properly maintained by FFF. Also, the FFF reconstruction is a reliable method for head and neck large bone and soft tissue defects, microvascular anastomosis on facial artery offering a good blood SUPPLY OF THE FLAP.
KEY WORDS
Ameloblastoma, Fibula-free flap, Maxillofacial reconstruction, Radical treatment.
Topics: Adult; Humans; Male; Female; Aged; Free Tissue Flaps; Ameloblastoma; Mandibular Neoplasms; Mandible; Plastic Surgery Procedures
PubMed: 38140922
DOI: No ID Found