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Toxicologic Pathology Oct 2023The 2023 annual Division of Translational Toxicology (DTT) Satellite Symposium, entitled "Pathology Potpourri," was held in Summerlin, Nevada, at the Society of...
The 2023 annual Division of Translational Toxicology (DTT) Satellite Symposium, entitled "Pathology Potpourri," was held in Summerlin, Nevada, at the Society of Toxicologic Pathology's 41st annual meeting. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and topics covered during the symposium included induced and spontaneous neoplastic and nonneoplastic lesions in the mouse liver, infectious and proliferative lesions in nonhuman primates, interesting presentations of mononuclear cell infiltrates in various animal models and a complex oral tumor in a rat.
Topics: Mice; Rats; Animals; Proteomics; Voting; Toxicology
PubMed: 38445604
DOI: 10.1177/01926233241231287 -
Indian Journal of Otolaryngology and... Feb 2024Ameloblastic carcinoma is a rare malignant neoplasm with characteristic histopathological features that are directed towards an aggressive surgical approach than benign...
Ameloblastic carcinoma is a rare malignant neoplasm with characteristic histopathological features that are directed towards an aggressive surgical approach than benign odontogenic lesions. It affects people of all ages, mostly in the posterior mandible, without a preference for race or gender. De novo cancer is one of its primary types, while the second type is defined as a malignant change from an antecedent case of benign ameloblastoma. The rapid progression of molecular biology led to the revelation that ameloblastoma contains a BRAF-V600E genetic mutation over 60%. Besides conventional ameloblastic carcinomas, rare histologic variants have also been described in the literature, including clear and spindle cells. These variants pose diagnostic challenges as to whether it is a dedifferentiation or a distinct entity. The dearth of data lends credence to the notion that these histologic variations are related to high-grade neoplasms and more aggressive outcomes. As a result, the current report intends to analyze a series of patients diagnosed with conventional ameloblastic carcinoma of the head and neck region with spindle and clear cell types along with a brief assessment of the literature.
PubMed: 38440659
DOI: 10.1007/s12070-023-04232-z -
Indian Journal of Otolaryngology and... Feb 2024Collision tumours, characterized by the simultaneous occurrence of two distinct neoplasms within the same anatomical site, are exceedingly rare in oral pathology. This...
Collision tumours, characterized by the simultaneous occurrence of two distinct neoplasms within the same anatomical site, are exceedingly rare in oral pathology. This case report presents an uncommon collision tumour involving desmoplastic ameloblastoma and squamous odontogenic tumour in the anterior maxilla of a 52-year-old male from the Indian population. Desmoplastic ameloblastoma is a variant of ameloblastoma known for its unique histopathological features, while squamous odontogenic tumour is a benign epithelial odontogenic tumour with distinctive clinical behaviour. The rarity of this occurrence emphasizes the need for accurate diagnosis and effective treatment strategies. This report discusses the clinical presentation, radiographic findings, and histopathological characteristics of this collision tumour. Through the presentation of this case, we aim to contribute to the understanding of these rare entities and their management considerations.
PubMed: 38440520
DOI: 10.1007/s12070-023-04314-y -
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 -
Annals of Maxillofacial Surgery 2023Ameloblastic carcinoma is defined as an ameloblastoma in which there is histological evidence of malignancy in primary tumour or recurrent tumour regardless if it has...
RATIONALE
Ameloblastic carcinoma is defined as an ameloblastoma in which there is histological evidence of malignancy in primary tumour or recurrent tumour regardless if it has metastasised or not. It is aggressive in nature.
PATIENT CONCERNS
The patient presented with a painful swelling associated with restricted mouth opening.
DIAGNOSIS
This is the clinical profile of a patient who has presented with a recurrent ameloblastic carcinoma.
TREATMENT
Histological features of the excised specimen resemble ameloblastic carcinoma constituting cytological atypia with tall columnar cells.
OUTCOME
Excision of tumour was done. Reconstruction was done using pectoralis major myocutaneous flap.
TAKE-AWAY LESSONS
Ameloblastic carcinoma is an aggressive tumour and constitutes destruction and distant metastatic spread. Hence, aggressive resection is the choice of treatment along with a long-term follow-up for better quality of life.
PubMed: 38405565
DOI: 10.4103/ams.ams_66_23 -
International Journal of Molecular... Feb 2024Ameloblastoma is a rare tumor but represents the most common odontogenic neoplasm. It is localized in the jaws and, although it is a benign, slow-growing tumor, it has...
Ameloblastoma is a rare tumor but represents the most common odontogenic neoplasm. It is localized in the jaws and, although it is a benign, slow-growing tumor, it has an aggressive local behavior and high recurrence rate. Therefore, alternative treatment options or complementary to surgery have been evaluated, with the most promising one among them being a targeted therapy with the murine sarcoma viral oncogene homologue B (), as in ameloblastoma the activating mutation V600E in BRAF is common. Studies in other tumors have shown that the synchronous inhibition of BRAF and human murine double minute 2 homologue (MDM2 or HDM2) protein is more effective than BRAF monotherapy, particularly in the presence of wild type p53 (WTp53). To investigate the MDM2 protein expression and gene amplification in ameloblastoma, in association with BRAF and p53 expression. Forty-four cases of ameloblastoma fixed in 10% buffered formalin and embedded in paraffin were examined for MDM2 overexpression and BRAF and p53 expression by immunohistochemistry, and for ploidy with fluorescence in situ hybridization. Sixteen of forty-four (36.36%) cases of ameloblastoma showed MDM2 overexpression. Seven of sixteen MDM2-positive ameloblastomas (43.75%) were BRAF positive and fifteen of sixteen MDM2-positive ameloblastomas (93.75%) were p53 negative. All MDM2 overexpressing tumors did not show copy number alterations for MDM2. Overexpression of MDM2 in ameloblastomas is not associated with MDM2 amplification, but most probably with MAPK activation and WTp53 expression. Further verification of those findings could form the basis for the use of MDM2 expression as a marker of MAPK activation in ameloblastomas and the trial of dual BRAF/MDM2 inhibition in the management of MDM2-overexpressing/BRAFV600E-positive/WTp53 ameloblastomas.
Topics: Animals; Humans; Mice; Ameloblastoma; In Situ Hybridization, Fluorescence; Mutation; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53
PubMed: 38396916
DOI: 10.3390/ijms25042238 -
Indian Journal of Pathology &... Apr 2024Adenoid ameloblastoma with dentinoid (AAD) is a hybrid odontogenic tumor comprising histopathological presentation of ameloblastoma (AM) and adenomatoid odontogenic...
BACKGROUND
Adenoid ameloblastoma with dentinoid (AAD) is a hybrid odontogenic tumor comprising histopathological presentation of ameloblastoma (AM) and adenomatoid odontogenic tumor (AOT) along with extracellular dentinoid material.
CASE PRESENTATION
A 35-year-old female reported an asymptomatic swelling in the left mandibular posterior region. Histopathological examination revealed composite features of AM with AOT along with dentinoid material, which stained positively with Van Gieson and trichrome stains.
CONCLUSION
The present case report serves to add further to the modicum of literature reports pertaining to AAD, which may gain recognition as a distinct entity in future World Health Organization (WHO) classification of odontogenic tumors.
Topics: Humans; Female; Adult; Ameloblastoma; Odontogenic Tumors; Mandibular Neoplasms; Mandible
PubMed: 38391318
DOI: 10.4103/ijpm.ijpm_186_22 -
Journal of Veterinary Diagnostic... Feb 2024Orofacial masses or swellings are a common presenting complaint in lagomorphs. Similar gross appearances of the masses can complicate clinical interpretation, and...
Orofacial masses or swellings are a common presenting complaint in lagomorphs. Similar gross appearances of the masses can complicate clinical interpretation, and histologic review often provides the final diagnosis. Underlying causes vary from infectious to neoplastic. Although inflammatory changes are most commonly reported, various neoplasms occur, although the prevalence of specific tumor types is relatively unknown. We reviewed retrospectively 120 cases (87.5% biopsy, 12.5% autopsy) of neoplastic and non-neoplastic orofacial masses received from January 2000-February 2023 at 2 institutions: University of Guelph, Canada (Animal Health Laboratory and Department of Pathobiology), and Finn Pathologists, United Kingdom. All final diagnoses were achieved through histologic assessment. We included masses or mass-like swellings from the oral cavity, including the mandible and maxilla, and surrounding skin and soft tissues of the oral cavity and jaw. Submissions included pet and commercial (meat and fur) rabbits. Neoplastic lesions were most common (60%), including trichoblastomas, papillomas, melanocytic neoplasms, sarcomas, round-cell tumors, carcinomas (including squamous cell carcinoma), lipomas, odontogenic neoplasms, polyps, osteoma, neuroma, peripheral keratinizing ameloblastoma, and apocrine adenoma. Inflammatory diagnoses (30%) included abscesses, osteomyelitis, dermatitis, and sialadenitis. Other diagnoses (7%) included cysts, as well as hyperplastic skin and proliferative bone lesions. Three cases had no definitive diagnosis. The importance of histologic assessment in diagnosing orofacial "masses" in rabbits is highlighted, given that the most common diagnostic category overall was neoplasia.
PubMed: 38389410
DOI: 10.1177/10406387241234326 -
Histology and Histopathology Feb 2024Hypoxia is characterized by a disparity between supply and demand of oxygen. The association between hypoxia and head and neck tumors is a topic of significant interest.... (Review)
Review
Hypoxia is characterized by a disparity between supply and demand of oxygen. The association between hypoxia and head and neck tumors is a topic of significant interest. Tumors frequently encounter areas with inadequate oxygen supply, resulting in a hypoxic microenvironment. Ameloblastoma is one of the most common benign odontogenic tumors of the maxillofacial region. It is a slow-growing but locally invasive tumor with a high recurrence rate. The literature has demonstrated the correlation between hypoxia and ameloblastoma, revealing a discernible link between the heightened expression of hypoxic markers in low oxygen conditions. This association is intricately tied to the tumoral potential for invasion, progression, and malignant transformation. Hypoxia profoundly influences the molecular and cellular landscape within ameloblastic lesions. The present review sheds light on the mechanisms, implications, and emerging perspectives in understanding this intriguing association to clarify the dynamic relationship between hypoxia and ameloblastoma.
PubMed: 38362601
DOI: 10.14670/HH-18-718 -
Malawi Medical Journal : the Journal of... Dec 2023Odontogenic keratocyst is a benign intraosseous lesion of odontogenic origin which is characterized by its aggressive nature. It is usually present in the mandibular...
Odontogenic keratocyst is a benign intraosseous lesion of odontogenic origin which is characterized by its aggressive nature. It is usually present in the mandibular posterior area, although it can also be found in the maxilla, particularly in the canine region. We discuss a unique example of OKC in the maxillary sinus involving the 27&28 region. Due to comparable clinical signs, this lesion is more prone to be mistaken for other lesions of the maxillary sinus, such as sinusitis or polyps. On the other side, this benign disease has the potential to develop into Ameloblastoma or squamous cell carcinoma. A favorable prognosis thus depends on early identification, precise diagnosis, appropriate treatment, and follow-ups.
Topics: Humans; Animals; Dogs; Maxillary Sinus; Odontogenic Cysts; Carcinoma, Squamous Cell
PubMed: 38362567
DOI: 10.4314/mmj.v35i4.6