Clinicopathological Features of Metastasis to the Oral and Maxillofacial Region-Multicenter Study.

BACKGROUND: This study aimed to investigate the clinicopathological features of metastases in the oral and maxillofacial regions. METHODS: In this retrospective study, biopsy records were obtained from referral centers for oral and maxillofacial diagnosis in Brazil, Guatemala, Mexico, and South Africa. RESULTS: A total of 120 cases were evaluated. Of these, 53.78% affected female patients, with a mean age of 57.64 years. Intraosseous lesions were more frequent, particularly in the posterior region of the mandible (49.58%). Clinically, most cases presented with symptomatic swelling, with an average evolution time of 25 months. The clinical diagnostic hypothesis in most instances was that of a malignant lesion. Breast cancer was the most common primary tumor location in females, while lung origin was most common in males. In most cases, the primary cancer was an adenocarcinoma (44.73%). The follow-up period was available for 29 cases, and out of these, 20 had died due to the disease. CONCLUSION: Although this is a rare condition, clinicians should be aware that any oral lesions have the possibility of being metastatic, particularly in individuals with a previous history of cancer. The findings from this study could assist clinicians in prompt diagnosing these lesions and subsequent conducting oncologic assessments and treatment.

Symptomatic subgemmal neurogenous plaque in patients with COVID-19: Is there an association?

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.

Spatial distribution of CD34 protein in primordial odontogenic tumour, ameloblastic fibroma and the tooth germ.

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.

Synchronous odontogenic tumors: A systematic review.

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.

Histomorphological evaluation, cell proliferation and endothelial immunostaining in oral and maxillofacial myofibroblastic lesions

Background: Myofibroblasts (MF) are mesenchymal cells with features of both fibroblasts and smooth muscle cells. Although these are usually reactive cells, they can lead to myofibroblastic tumors that may share clinical and histomorphological characteristics but with different prognosis. The aim of this study is to perform a histomorphological evaluation as well as to compare and evaluate two different cell proliferation immunomarkers and two endothelial markers in a group of oral and maxillofacial myofibroblastic lesions (MFL). Material and methods: Cross-sectional and retrospective study. Demographic, clinical, histomorphological and immunohistochemical characteristics of 39 cases of MFL were analyzed. Immunohistochemical reactions were performed with the Ki67, MCM2, CD34 and CD105 antibodies. Kruskal-Wallis test and Spearman correlation analysis were used. Results: Four cases of nodular fasciitis (NF), 18 myofibromas (My), 6 desmoplastic fibromas (DF), 7 inflammatory myofibroblastic tumors (IMT) and 4 myofibroblastic sarcomas (MFS) were studied. There were twenty women (51.2%); the median age was 13 [Q1-Q3: 8-24] years and most cases occurred in the mandible (48.7%). A statistically significant difference with MCM2 immunostaining (p=0.0221) was observed between the MFL; furthermore, a correlation between CD34 and CD105 immunostaining in NF (p <0.0001) and IMT (p=0.0408), between MCM2 and CD34 in IMT (p=0.0362) and between MCM2 and CD105 in MFS (p <0001) were found. Conclusions: MCM2 immunostaining could assess more clearly the cell growth fraction in MFL. The correlation between MCM2 and CD34 in IMT and between MCM2 and CD105 in MFS are indicative of the high activity of these lesions. These results emphasize the importance of the studied immunohistochemistry markers as possible tools for a better characterization of some of the MFL. (AU)

Carcinoma ameloblástico mandibular: un diagnóstico infrecuente y desafiante / Mandibular ameloblastic carcinoma: an infrequent and challenging diagnosis

El carcinoma ameloblástico es un tumor odontogénico epitelial maligno, infrecuente y de mal pronóstico. Histopatológicamente es una lesión que conserva un patrón de diferenciación ameloblastomatoso, pero presenta características citológicas de malignidad. Debido a su rareza, existe poca información sobre su comportamiento biológico, el cual es reconocido en la literatura por ser inespecífico y variable, ya que puede presentarse como una lesión con características compatibles con una lesión benigna o como una entidad patológica agresiva altamente maligna. Esto último ha supuesto una dificultad no solo en su diagnóstico, sino también en la planificación terapéutica. Se reporta un caso de un carcinoma ameloblástico mandibular en un paciente perteneciente a la séptima década de la vida, destacando sus características clínicas, imagenológicas e histológicas variables que permitieron llegar a un diagnóstico correcto. (AU)

Ameloblastic carcinoma is a rare, malignant epithelial odontogenic tumor with a poor prognosis. Histopathologically it preserves an ameloblastomatous differentiation pattern but shows cytological features of malignancy. Due to its rarity, there is limited information on its biological behavior, which is recognized in the literature for being nonspecific and variable, as it may present as a lesion with characteristics compatible with a benign lesion or as a highly malignant aggressive pathological entity. The latter has been a difficulty not only in its diagnosis but also in the therapeutical planning. This article reports a case of a mandibular ameloblastic carcinoma occurring in a patient in the seventh decade of life, highlighting its variable clinical, imaging and histological characteristics that allowed us to reach a definitive diagnosis. (AU)

Oral Manifestations of Coronavirus Disease 2019 (COVID-19): A Comprehensive Clinicopathologic and Immunohistochemical Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents rapid transmission and significant mortality worldwide. It is responsible for coronavirus disease 2019 (COVID-19). The disease presents diverse clinical symptoms, including fever, cough, dyspnea, and pneumonia. However, other manifestations associated with COVID-19 need to be clarified, leading specialists to an early diagnosis and better prognosis. We describe the spectrum of clinicopathologic COVID-19-related oral lesions that can be the first and/or the unique manifestation of the disease. Fourteen patients with a mean age of 58 years (range: 23 to 88 y) with oral lesions were included. All patients were confirmed to be infected with SARS-CoV-2 by reverse transcription polymerase chain reaction testing. Patients demonstrated mild symptoms, including dysgeusia, anosmia, fever, and headache. The lesions were recognized and classified into 2 groups: (1) lesions caused by ischemia and/or hemorrhage and (2) lesions secondary to inflammatory events associated with viral load. The palate was most affected (n=8), followed by the tongue (n=4), and both the lip and palate (n=2). Histologic analysis demonstrated thrombosis of small arteries and capillaries, associated with areas of hemorrhage and chronic inflammatory infiltrate. Immunohistochemistry showed positive staining for spike protein (SARS-CoV and SARS-CoV-2) and angiotensin-converting enzyme 2 in the surface epithelium, salivary glands, inflammatory cells, and endothelial cells. Although the incidence of oral lesions among patients infected with SARS-CoV-2 appears to be uncommon, these findings suggest that the oral mucosa can also be a target organ for SARS-CoV-2.

Hybrid odontogenic lesions: A systematic review of 203 cases reported in the literature.

BACKGROUND: Hybrid odontogenic lesions combine histopathological characteristics of two or more odontogenic cysts and/or tumours. The aim of this study was to evaluate the available data on hybrid odontogenic lesions (HOL) and to analyse their epidemiological/clinical features and biological behaviour. METHODS: An electronic search was done in January 2021 using multiple databases. Eligibility criteria encompassed publications with sufficient clinical and histological information to confirm the tumours' diagnoses. RESULTS: A total of 147 articles were included in this study, comprising 203 cases. Calcifying odontogenic cyst associated with odontoma (COC/OD) (37/18.2%) was the most common HOL. Females were more affected with a mean age of 24.9 years. Lesions presented as asymptomatic swellings, with a mean evolution time of 8.2 months (0.3-96), and mean tumour size of 4.8 cm (0.3-7). Radiographic aspects frequently showed radiolucent (139/68.4%) and unilocular (52/25.6%) images with well-defined limits (48/23.6%). The lesions mostly affected mandibular pre-molars (69/34%) and mandibular molars (69/34%) regions. Enucleation (89/43.8%) and surgical excision (59/29%) were the most common treatment modalities. The mean follow-up time was 33.8 months (0.5-216 months) and recurrences were observed in four cases (1.9%), all of which were central odontogenic fibroma associated with central giant cell granuloma (COF/CGCG). CONCLUSION: COC/OD is the most common HOL and recurrence is a rare event, being usually associated with the diagnosis of COF/CGCG.

Peripheral odontogenic keratocyst: Clinicopathological and immunohistochemical characterization.

OBJECTIVE: The aim of this study is to present and discuss the salient clinicopathological features, differential diagnosis and epithelial immunohistochemical profile of three additional cases of peripheral odontogenic keratocyst (POKC) and to present a review of the literature. POKC is a locally aggressive odontogenic lesion. The peripheral variant of the odontogenic keratocyst is rare and more frequently located in anterior gingiva. MATERIAL AND METHODS: We present the clinicopathological features of 3 new cases of POKC (2 women and 1 man; age range: 14-74 years). Immunohistochemical study included CK7, CK14, CK19 and Ki-67, and a systematic review of the literature was performed in PubMed, Scopus and Web of Science databases. RESULTS: All cases were located in the anterior gingiva (2 in maxilla and 1 mandible), and none corresponded to Gorlin-Goltz syndrome. High expression of CK14 was seen in all cases, with CK19 and CK7 been only focally positive. The expression of Ki-67 was located in the basal and parabasal cells in all cases. CONCLUSIONS: POKC is a rare gingival lesion that seems to originate from remnants of dental lamina or from the basal cells of the gingival epithelium and present a similar histopathology as compared to intraosseous OKC.

Value of the toluidine blue test as an aid to determine the biopsy site in actinic prurigo cheilitis.

Actinic prurigo (AP) is a type of photodermatosis that primarily affects the Latin American mestizo population. Histologically, AP cheilitis exhibits acanthosis with spongiosis and vacuolation of the basal cell layer overlying a dense lymphocytic inflammatory infiltrate that forms well-defined lymphoid follicles. Toluidine blue is a thiazide, acidophilic, and metachromatic dye used in vivo to selectively stain the acidic components of tissues such as sulfates, carboxylates, and phosphate radicals that are incorporated into DNA and RNA. It is necessary to develop a method that allows detecting, on clinical grounds the area of the lesion in which it is more feasible to find such structures. Thus to increase the sensitivity of the biopsy, in AP cheilitis to accurately identify where the lymphoid follicles reside, based on the higher concentration of DNA in such structures and thus confirm the diagnosis. In this study, staining was positive in 85% of patients with AP cheilitis, in 14 of whom 82% lymphoid follicles were observed by histopathology. One of the pathologist's problems in establishing the diagnosis of AP is that the main histopathological characteristics are not always identified in the submitted samples because it is not easy to clinically identify the most representative site of the lesion selected for performing a biopsy. Based on our results, we propose using toluidine blue as an auxiliary method to choose a tissue sample to facilitate the diagnosis and allow clinicians to make clinical correlations between the histopathological and therapeutic findings.

Langerhans cell histiocytosis in the oral and maxillofacial region: An update.

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.

Capsaicin intake and oral carcinogenesis: A systematic review / Ingesta de capsaicina y carcinogénesis oral: una revisión sistemática

Background: Chili is the most heavily and frequently consumed spice, either as a flavouring or colouring agent,and it is also a major source of pro-vitamin A, vitamin E and C. The main capsaicinoid found in chili peppers iscapsaicin. It has been demonstrated that capsaicin acts as a cancer-suppressing agent through its antioxidant andanti-inflammatory effects, by blocking several signal transduction pathways. Oral squamous cell carcinoma isone of the most prevalent cancer worldwide. It is noteworthy that in countries where populations of diverse ethnicgroups co-exist, differences have been observed in terms of incidence of oral cancer. The variances in their dietcould explain, at least in part, these differences. The objective of this systematic review is to explore if there isevidence of a possible relationship between capsaicin intake and the incidence of oral squamous cell carcinoma,and discuss such association.Material and Methods: A bibliographical search was made in PubMed, Scopus and Web of Science databases, andfinally 7 experimental studies were included; OHAT risk of bias tool was used to assess their quality.Results: All the studies confirm that capsaicin is a chemopreventive agent that prevents the development of oralcancer, through inhibition of malignant cell proliferation and increase of apoptosis.Conclusions: More human studies are needed in order to clarify the real link between consumption of chili (cap-saicin) and the prevalence of oral cancer.(AU)

Primordial odontogenic tumor: report of 2 new cases.

Primordial odontogenic tumor (POT) is a recently described benign odontogenic tumor, with only 16 cases reported in the literature. We present 2 new cases of POT affecting the mandible. Case 1 is that of 12-year-old girl with an asymptomatic, slow-growing mass, causing facial asymmetry. Radiography showed a well-defined unilocular radiolucency surrounding an impacted second premolar. Case 2 is that of a 13-year-old girl with a mass involving the crown of the unerupted third molar and showing similar radiographic features. Microscopically, both lesions were composed of variably cellular fibromyxoid tissue surrounded by thin ameloblastic epithelium, with stellate reticulum-like areas, but no mineralized tissue, yielding the diagnosis of POT. Immunohistochemical analysis showed diffuse expression of CK14 in epithelial cells, whereas CK19 was expressed mainly in the basal layer. Syndecan-1 (CD138) was expressed in the stellate-like regions and in the subepithelial zone. Both patients were treated surgically, with no signs of recurrence seen after 15 and 60 months, respectively.

Central odontogenic fibroma: an international multicentric study of 62 cases.

OBJECTIVE: The aim of this study was to report the clinicopathologic features of 62 cases of central odontogenic fibroma (COdF). STUDY DESIGN: Clinical and radiographic data were collected from the records of 13 oral pathology laboratories. All cases were microscopically reviewed, considering the current World Health Organization classification of tumors and were classified according to histopathologic features. RESULTS: There were 43 females and 19 males (average age 33.9 years; range 8-63 years). Clinically, COdF lesions appeared as asymptomatic swellings, occurring similarly in the maxilla (n = 33) and the mandible (n = 29); 9 cases exhibited palatal depression. Imaging revealed well-defined, interradicular unilocular (n = 27), and multilocular (n = 12) radiolucencies, with displacement of contiguous teeth (55%) and root resorption (46.4%). Microscopically, classic features of epithelial-rich (n = 33), amyloid (n = 10), associated giant cell lesion (n = 7), ossifying (n = 6), epithelial-poor (n = 3), and granular cell (n = 3) variants were seen. Langerhans cells were highlighted by CD1a staining in 17 cases. Most patients underwent conservative surgical treatments, with 1 patient experiencing recurrence. CONCLUSIONS: To the best of our knowledge, this study represents the largest clinicopathologic study of COdF. Most cases appeared as locally aggressive lesions located in tooth-bearing areas in middle-aged women. Inactive-appearing odontogenic epithelium is usually observed within a fibrous/fibromyxoid stroma, occasionally exhibiting amyloid deposits, multinucleated giant cells, or granular cells.

Salivary Gland Tumors: A Retrospective Study of 164 Cases from a Single Private Practice Service in Mexico and Literature Review.

Salivary gland tumors (SGT) represent an uncommon heterogeneous group of tumors with complex clinical and pathological characteristics. The prevalence of these lesions varies between studies but has been estimated between 3 and 6% of all tumors in the head and neck region. The present study aimed to evaluate the distribution and demographic findings of salivary gland tumors diagnosed in an oral pathology service in Mexico. A retrospective descriptive cross-sectional study was performed. A total of 164 cases of SGT from a private oral pathology service were diagnosed between 2000 and 2019 in Mexico City. All cases were reviewed histologically, and demographic data and histopathological diagnoses were collected. A total of 110 (67.1%) tumors were benign, and 54 (32.9%) were malignant. The majority of patients were female (n = 100, 61.0%) with an overall female:male ratio of 1.6:1. The minor salivary glands were affected more than the major salivary glands (68.9% vs. 25.6%). The palate (n = 67, 40.9%) was the most commonly affected site, followed by the parotid gland (n = 37, 22.6%), lips (n = 16, 9.8%), and buccal mucosa (n = 14, 8.5%). Pleomorphic adenoma (n = 88; 80.0%) and mucoepidermoid carcinoma (n = 16, 29.6%) were the most frequent benign and malignant tumors, respectively. The general features of SGT from the studied Mexican population shared some similarities and differences compared to previously reported series from various parts of the world.

An international collaborative study of 105 new cases of adenomatoid odontogenic tumors.

OBJECTIVE: The aim of this study was to report the clinicopathologic features of 105 new cases of adenomatoid odontogenic tumor (AOT) from Brazil, Guatemala, Mexico, and South Africa. STUDY DESIGN: Clinical and radiographic data were collected from records of 5 oral pathology laboratories, and all cases were microscopically reviewed. RESULTS: This series of cases included 36 (34.2%) from South Africa; 33 (31.4%) from Brazil; 23 (21.9%) from Mexico; and 13 (12.3%) from Guatemala. Seventy-two patients (68.5%) were females and 33 patients (31.4%) were males, with an average age of 19.2 years. The tumors predominantly affected the anterior maxilla (48.5%), followed by the anterior mandible (29.5%); posterior mandible (15.2%); and posterior maxilla (6.6%). Sixty-three tumors (63.6%) were follicular, 34 (34.3%) were extrafollicular, and 2 (2%) were peripheral. In most cases, the tumors caused considerable cortical expansion (average size 3.4 cm). Microscopically, most cases showed rosette-like and duct-like structures. CONCLUSIONS: This is one of the largest case series of AOTs reported in the literature and the first multicenter study involving populations from Latin America and South Africa. In a fifth of the present cases, the posterior regions of the gnathic bones were affected and the tumors demonstrated larger sizes compared with cases occurring in other populations.