Background
Primordial odontogenic tumour is a benign mixed neoplasm of recent description, which has histological similarities with other odontogenic tumours such as the ameloblastic fibroma. In this ...article, we investigate the architecture of the sub‐epithelial layer of mesenchymal cells expressing the marker CD34 in primordial odontogenic tumour.
Objective
Analyse the spatial patterns of CD34 expression in primordial odontogenic tumour and compare them with those in ameloblastic fibroma and the normal tooth germ by means of objective imaging approaches, to better characterise these lesions.
Methods
Two cases of primordial odontogenic tumour, four cases of ameloblastic fibroma and two cases of tooth germ in cap and bell stages were used for morphological, structural and immunohistochemical analyses.
Results
CD34 expression was found in vascular endothelium of primordial odontogenic tumour, ameloblastic fibroma and tooth germ. In addition, a characteristic sub‐epithelial expression was observed only in primordial odontogenic tumour, corresponding to 84%–86% of the sample boundaries. Moreover, the zone expressing CD34 corresponded with a higher cellularity, which was absent in ameloblastic fibroma and tooth germ.
Conclusion
Image analysis of the primordial odontogenic tumour architecture revealed characteristics absent in other odontogenic tumours and tooth germs. This study provides additional information to support the idea that this neoplasm is a distinct entity from early stage AF or developing odontoma.
Background
Myofibromas are rare benign neoplasms composed of myoid cells and myofibroblasts. This study aimed to systematically review case reports and a series of myofibromas (MF) and ...myofibromatosis (MFT) occurring in the oral and maxillofacial regions in order to describe their main clinicopathological features.
Methods
This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. Electronic searches were conducted in 2023 in four databases: MEDLINE/PubMed, Web of Science, Scopus, and EMBASE. A manual search and a search in the grey literature were also conducted. The lesions were classified as MF or MFT according to their original report.
Results
A total of 169 cases were included in this systematic review. Men were slightly more affected, with a painless nodule. When occurring in soft tissue, MF usually developed in the gingiva (mean age:29.23 ± 21.93 years) and when it was intra‐osseous, it occurred more frequently in the posterior mandible (mean age:14.33 ± 15.62 years). MFT occurred mainly in the mandible and was predominantly described as well‐circumscribed masses of spindle cells organized in fascicles with a prominent vascular activity in a hemangiopericytoma‐like pattern. The lesions were mainly positive for smooth muscle actin and vimentin immunomarkers. Surgical excision was the treatment of choice in the majority of cases and recurrence was observed in only three cases.
Conclusion
MF and MFT affect more men, with an indolent clinical course. Intra‐osseous tumors and MFT seem to occur more frequently in younger individuals. These lesions seem to have a good prognosis and low recurrence.
Abstract
This systematic review aimed to incorporate published information about synchronous odontogenic tumors (SOTs) with an analysis of the demographic and clinical characteristics from the cases ...published in the literature. Case reports and case series of SOT were searched in PubMed, Web of Science, Scopus, and EMBASE. A descriptive statistical analysis was performed. Twenty‐eight studies comprising 30 cases of SOTs were included. Considering all cases published, SOTs mostly occurred simultaneously in the maxilla and mandible (
n
= 19/63.3%). Lesions were bifocal in 13 (43.3% of all the 30 cases) and multifocal in 17 cases (56.7% of all the 30 cases). All SOTs available in the literature presented the same type of lesion, and two of them also involved another different SOT (
n
= 2/6.7% of all the 30 cases). Out of all published cases, the most frequent SOTs in the literature were odontomas (
n
= 10/33.3% of all the 30 cases), squamous odontogenic tumors (OTs) (
n
= 8/26.7% of all the 30 cases), calcifying epithelial OTs (
n
= 8/26.7% of all the 30 cases), and adenomatoid OTs (
n
= 2/6.7% of all the 30 cases). Considering all SOTs cases included, the overall recurrence was 13.3%. Inside a subgroup of the lesion, synchronous calcifying epithelial OT presented the highest (25%). Five cases (16.7% of all the 30 cases) had a previously associated syndrome, with two cases of Schimmelpenning syndrome being reported. Among published SOTs, odontomas were the most common. All SOTs available in the scientific literature showed the same type of OT and mainly affected both jaws simultaneously. Only a few of these cases were associated with a syndrome.
Background
Langerhans cell histiocytosis (LCH) is a rare disorder characterized by abnormal proliferation and infiltration of histiocytic cells.
Methods
This review focused on the main aspects ...associated with LCH.
Results
LCH can involve single or multiple organs and systems, with bone and skin being the most commonly affected sites. Regarding skeletal manifestations, the jawbones are involved in about 20%–30% of all cases. Such lesions may present as unilocular or multilocular images mainly affecting the posterior mandible. Oral soft tissue lesions may also occur, with the gingiva and hard palate being the most frequently affected sites.
Conclusion
The diagnosis and management of LCH are challenging, requiring a multidisciplinary approach, with dentists playing a central role since oral manifestations can be the first sign of the condition.
Objective
This study aimed to assess the frequency of KRAS mutation and its association with the presence of the MAPK/ERK signaling pathway proteins in adenomatoid odontogenic tumors.
Study Design
...Paraffin‐embedded tissue samples from nine cases of adenomatoid odontogenic tumor were used.
Genomic DNA was extracted from each sample; in one case, genetic mutations in 50 cancer‐associated genes were examined by next‐generation sequencing. Hotspot mutations in the RAS family were analyzed by Luminex assay using the remaining eight cases. Subsequently, immunohistochemistry for KRAS, CRAF, BRAF, EGFR, ERK, MEK, and BRAFV600E was performed.
Results
A KRAS G12D missense mutation was detected in the DNA sequence of the tumor cells, but it was not detected in the stromal tissue. KRAS G12V and KRAS G12R mutations were detected in two and four cases, respectively. For immunohistochemistry, all the cases were EGFR, KRAS, BRAF, CRAF positive, one case was ERK negative,and one case was MEK and ERK negative, all the other remaining cases were MEK and ERK positive.
Conclusion
KRAS mutation at codon 12 and the presence of MAPK/ERK pathway proteins were detected suggesting their association with tumorigenesis of adenomatoid odontogenic tumors.
Odontogenic tumors comprise a heterogeneous group of lesions that ranges from hamartomas to benign and malignant neoplasms of variable aggressiveness. This article shows how the lack of uniform ...criteria employed for their proper identification, as well as the histomorphologic similitude found among some of them which behaves in different way, and the scantiness of proper methods to determine their precise origin makes necessary to recognize that at present, in spite of having more or less strict diagnostic criteria which have been internationally accepted, there is a need to continue developing research in the epidemiological, clinico-pathological, morpho-physiological and therapeutical fields in this area of the maxillofacial pathology.
Primordial odontogenic tumor (POT) is a benign mixed epithelial and mesenchymal odontogenic tumor included into the current World Health Organization (WHO) classification of Head and Neck tumours in ...2017. As far as the authors have confirmed, only eight cases of this tumor have been reported so far. This paper reports a case of POT that occurred in the right mandible of a 5‐year‐old patient. Panoramic radiograph showed a well‐defined homogeneous radiolucency displacing the unerupted second deciduous molar to the deep part of the mandible. Histopathologically, the tumor was composed of cell‐rich mesenchymal tissue with myxoid areas, surrounded by columnar epithelium and non‐keratinized cuboidal epithelium in the outer layers. The histopathological diagnosis was POT. The expression patterns of cytokeratins (CK) 14, 18, 19, vimentin and CD34 suggested that the grade of differentiation of the POT was approximately equivalent to that of normal primary tooth germ tissues in cap stage to late bell stage.
Background
Subgemmal neurogenous plaques (SNP) are composed of neural structures found in the posterolateral portion of the tongue, rarely biopsied as most of them are asymptomatic or eventually only ...clinically managed. We aimed to investigate a case series of possible correlation of symptomatic subgemmal neurogenous plaque (SNP) with coronavirus disease 2019 (COVID‐19).
Methods
Eleven formalin‐fixed paraffin‐embedded cases from patients with previous confirmed COVID‐19 (by RT‐PCR) were retrieved from two pathology files. Histological sections were morphologically studied, and then submitted to immunohistochemical reactions against S‐100 and neurofilament proteins, neuron‐specific enolase, Glial fibrillary acidic protein (GFAP), synaptophysin, CD56, Ki67, cytokeratins (7, 8–18, 19, 20), nucleocapsid and spike proteins (SARS‐CoV‐1; and ‐2) and epithelial membrane antigen (EMA) antibodies. Clinical data were retrieved from the patients' medical files, including the symptoms and the complete history of the progression of the disease.
Results
The patients who had COVID‐19 included in this study experienced painful lesions in the tongue that corresponded to prominent or altered SNP. Microscopically, neural structures were positive for S‐100, GFAP and neurofilament protein. And the cellular proliferative index (by Ki‐67) was very low.
Conclusion
Thus, based on the current results, we hypothesize that symptomatic SNP may be a late manifestation of COVID‐19 infection.
PDF
