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Cytopathologic analysis is feasible and provides detailed morphological characterisation of head and neck lesions.To integrate the available data published on fine-needle aspiration cytology (FNAC) used for the diagnosis of plasma cell neoplasms (PCN) of the head and neck region.Searches on PubMed, Web of Science, Embase, and Scopus were performed to compile data from case reports/case series published in English. The Joanna Briggs Institute tool was used for the critical appraisal of studies.A total of 82 studies comprising 102 patients were included in this review. There was a predilection for men (68.6%) (male/female ratio: 2.1:1). Individuals in their 50s (29.4%), 60s (22.5%), and 70s (22.5%) were more often affected. The thyroid gland (26.2%) was the main anatomical location, followed by scalp (15.5%), neck/cervical region (15.5%), jaws (13.6%), and major salivary glands (13.6%). For FNAC analysis, a smear was employed in 41 (40.6%) cases and a cell block was used in four (3.9%). In 56 (55.4%) reports, no cytological methods were available. Morphologically, 34 (56.7%) cases had a diagnosis of PCN with agreement between cytopathology and histopathology. The rate of wrong diagnoses when using cytology was 27.5%. Immunophenotyping was performed in 49 (48%) of the cases. The 69-month disease-free survival rate was 60.2%, while the 27-month overall survival rate was 64.1%.This study reinforces that FNAC can be an ancillary tool in the first step towards the diagnosis of PCN of the head and neck region, especially when applying a cell block for cytological analysis.

Obtaining robust evidence about the local mortality levels, trends and impact of oral cavity/base of tongue cancers and lip cancer, especially for women, is imperative in the fight against cancer. This descriptive retrospective ecological time-series study explored trends in oral cavity/base of tongue cancers and lip cancer mortality rates for women in Brazil from 1980 to 2018, by geographic region and anatomical location.The crude and age-adjusted annual mortality rates were obtained by sex, anatomical location and macro-regions of Brazil. The number of deaths from oral cavity/base of tongue cancers and lip cancers in Brazil was based on official population counts and estimates. The annual percentage change was calculated based on age-adjusted rates. Data set were analysed using the Joinpoint Regression program.A total of 81,918 individuals died of oral cavity/base of tongue cancers and lip cancer between 1980 and 2018 in Brazil. The age-adjusted mortality rate for women was 0.47 and 0.57 per 100,000 in 1980 and 2018, respectively. The cumulative female mortality rates standardized by age were 0.01/100,000 for lip cancer and 0.5/100,000 for oral cavity and base of tongue cancers. A decrease in deaths related to oral cavity and base of tongue cancers was identified in the 1980s; however, over the last two decades, there has been an increase in the number of deaths of women with cancer at the base of tongue and neighbouring areas and on the floor of mouth. Importantly, Brazilian regions showed wide variability in trends of oral cavity, base of tongue and lip cancers rate and, in 2018, the regions with the highest rates were the Southeast, South and Northeast for both sexes and specifically for women. The North region showed the greatest recent significant upward trend.During the last 38 years, Brazil has shown a significant increase in the trend of the mortality rate due to oral cavity/base of tongue and lip cancers in women. Preventive strategies with control of risk factors should be strongly emphasized in order to improve the survival rates of individuals with oral cavity/base of tongue and lip cancers.

Attention-deficit/hyperactivity disorder (ADHD) is a childhood neurodevelopmental disorder primarily characterized by inattention and hyperactivity that affects approximately 7.2% of children and adolescents worldwide. This study aimed to assess whether children and adolescents with ADHD were more likely to have dental trauma when compared to their healthy peers.This study was reported following the statements proposed in MOOSE (Meta-analyses Of Observational Studies in Epidemiology). PubMed, Web of Science, Scopus, Embase, APA PsycINFO, LILACS, and grey literature were searched until October 2022. Observational studies with a control group were eligible. The risk of bias was assessed using the Newcastle-Ottawa Scale. The meta-analysis was performed using the R language. GRADE (Grading of Recommendations Assessment, Development and Evaluation) was applied.A total of 239 studies were detected; of these, six were included in the qualitative synthesis and four were merged in the meta-analysis (OR = 1.80 [1.16-2.80]; IChildren and adolescents with ADHD are more likely to have dental trauma than their non-ADHD peers. However, due to limitations in the design of the included studies, a causal relationship cannot be established.

Objectives This study evaluated the influence of methotrexate (MTX) and periodontal therapy on the composition of the oral-gut microbiota of individuals with RA. Methods Thirty-seven individuals with RA were evaluated at three time points. The composition of the oral and gut microbiota was assessed by amplifying the V4 region of the 16S gene from subgingival plaques and stools. Results MTX tended to reduce the alpha diversity of the oral and gut microbiota, an effect that was partially reversed in the oral microbiota after periodontal treatment. The relative abundance of the oral microbiota was directly influenced by periodontal status. Conversely, periodontitis did not influence the gut microbiota. MTX treatment did not affect the periodontal condition; however, it modified the interactions between clinical parameters and the oral-gut microbiota, with the emergence of novel and simplified correlations. Porphyromonas gingivalis was linked to increased production of neutrophil extracellular traps (NET) regardless of periodontal status and this periodontopathogenic bacterium induced significant production of NET in vitro, particularly in individuals with RA. Conclusion MTX and periodontal treatment directly affected the composition and richness of the oral-gut microbiota, with the emergence of different microbial groups. P. gingivalis and NET typify the microbial-host interaction in RA and periodontitis.

Oral malignant infiltrations (OMI) are relevant for the diagnosis and prognosis of leukaemia/lymphoma. This study analysed the oral health status and OMI of individuals with leukaemia/lymphoma.A retrospective analysis (2010-2021) of data from individuals seen at a specialized hospital-based dental service in Brazil.A total of 781 cases of leukaemia/lymphoma were surveyed. Acute lymphoblastic leukaemia (30.1%), acute myeloid leukaemia (AML; 26.0%), and non-Hodgkin lymphoma (22.2%) were the most common diagnoses. The first (21.3%) and second (19.3%) decades of life were the most affected. Overall, dental caries (36.7%) and periodontal changes (34.6%) were the most frequent oral conditions. OMI occurred in 25 (3.2%) individuals. Lesions mainly involved the gingiva (80%) and patients diagnosed with AML (64%). Death (p0.001) and worse periodontal condition (p=0.036) were more frequent among adults with OMI than among those without OMI. Death (p=0.002) was more frequent among paediatric individuals with OMI than among those without OMI. When controlling for underlying disease, no association was observed between OMI and these outcomes.Oral status of individuals with leukaemia, particularly those with acute leukaemia or lymphoma, should be closely monitored since one or multiple conditions may occur, including OMI, which may influence disease outcomes.

Leishmaniasis is a tropical disease caused by protozoan parasites of the genus Leishmania. Mucosal leishmaniasis has been described as secondary to the cutaneous form; however, isolated mucosal involvement can also occur. Specifically, mucosal leishmaniasis of the lip is poorly described and its diagnosis challenges clinicians.We herein report a case of mucosal leishmaniasis affecting the lower lip without cutaneous involvement in a 20-year-old Venezuelan man. The patient had no relevant past medical history. Clinically, a mass-like lesion with ulcerations and crusts was observed.Microscopically, the lesion was composed of granulomatous inflammation along with macrophages containing intracytoplasmic inclusions similar to round-shaped Leishmania. The species Leishmania (Viannia) braziliensis was confirmed. Treatment with meglumine antimonate was effective. The lesion healed satisfactorily, and no side effects or recurrences were observed.Clinicians should be aware of isolated forms of mucosal leishmaniasis of the lip, even in cases where the cutaneous lesion is undetected or clinically manifests as self-limiting. Knowing the endemic areas in the scenario of the dynamics of the ecoepidemiology of leishmaniasis is also essential for surveillance and counselling of the population.

Anxiety and depression are frequent conditions among individuals undergoing antineoplastic therapy, but their relationship with oral mucositis is unclear. This systematic review evaluated the potential association of anxiety and depression with frequency and severity of chemo/radiotherapy-induced oral mucositis.Electronic searches were undertaken in five databases supplemented by manual scrutiny and gray literature searches in three other databases. The risk of bias was assessed using the Joanna Briggs Institute tool.Eight observational studies conducted on 954 individuals (male-to-female ratio: 1.1:1; age range: six-82 years). Three (37.5%) studies included patients with solid tumors, two (25%) studies included hematopoietic/lymphoid tissue tumors, and two (25%) studies comprised mixed types of malignant neoplasms. Eight different instruments were used to assess oral mucositis, while seven different instruments were used to evaluate anxiety and depression. Associations of anxiety and/or depression with oral mucositis severity were reported in six (75.0%) studies. Oral mucositis-related symptoms, especially pain, were linked with depression in three (37.5%) studies.A relatively low number of cases and data heterogeneity hamper definitive conclusion about the potential association between anxiety/depression and oral mucositis. Further studies that could guide more personalized treatments are warranted to investigate this plausible bidirectional interaction.

Background Lymphomas in the oral and oropharyngeal regions are relatively uncommon, and their diagnosis is challenging and complex due to the myriad histopathological subtypes. Herein, we report a large series of oral and oropharyngeal lymphomas and compare our data with the currently available literature. Methods All cases diagnosed as lymphomas affecting the oral and oropharyngeal regions were retrospectively retrieved from seven Brazilian institutions. Clinicodemographic data and histopathological features were evaluated and described, while a comprehensive literature review was undertaken in order to compare our findings. Results A total of 304 cases of oral and oropharyngeal lymphomas were obtained, mostly affecting individuals aged 60-69 years (n = 68) with a mean age at diagnosis of 54.2 ± 20.1 years. Males and females were equally affected. Mature B-cell neoplasms (87.2%) were the most common group, followed by mature T- and NK-cell neoplasms (11.2%) and precursor lymphoid neoplasms (1.6%). The most frequent subtypes in each group were diffuse large B-cell lymphomas, not otherwise specified (n = 99), extranodal NK/T-cell lymphomas, nasal type (n = 12), and B-lymphoblastic leukaemia/lymphomas, not otherwise specified (n = 4). The most commonly involved sites were the palate (26.3%), mandible (13%), and maxilla (10.5%). Conclusion Diffuse large B-cell lymphoma, not otherwise specified, remains the most common subtype of lymphomas in the oral and oropharyngeal region. Older patients are the most affected, with no gender predilection and the palate and jaw are usually affected.

Middle-aged and old adults (≥ 50 years) diagnosed with Cowden syndrome (CS) with orofacial manifestations are uncommon. We describe a case of CS in a 53-year-old female showing “narrow bird-like” face, macrocephaly, acral keratoses, oral candidiasis, burning in the mouth, and multiple asymptomatic papillomatous lesions with a cobblestone pattern distributed on the alveolar ridge, tongue, buccal mucosa, and commissure. The histopathological features of lesions of the oral mucosa were those of papillary fibroepithelial hyperplasia. Immunohistochemistry revealed strong positivity for PTEN and p53 in most epithelial cells, while the expression of Bcl-2, S-100, and Ki-67 was weak/negative. According to a review conducted in PubMed, Web of Science, Embase, and Scopus for the analysis of reports of CS individuals ≥ 50 years with orofacial manifestations, 56 cases have been described in literature. Predilection for women was observed, with a female:male ratio of 2.3:1. Thirty-five (62.5%) individuals developed some malignant neoplasms. Oral health providers should be aware of the orofacial aspects of CS, including multiple papillomatosis, which can be an important criterion for diagnosis. Since malignancies may occur in older adults with CS, the need for strict surveillance is necessary. The present case has been under follow-up for 7 years without evidence of other manifestations.

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.

A metastatic giant cell–rich osteosarcoma (GCRO) to the jaws is an exceedingly rare neoplasm. To date, fewer than 10 cases have been reported in the English language literature. In this article, we describe an additional case of a metastatic GCRO that presented the diagnostic challenge of a painless mass in the posterior mandible of a 19-year-old girl who exhibited rapid and aggressive local growth. The lesion was confirmed radiologically as an ill-defined expansive osteolytic mass showing cortical perforation. Microscopically, the presence of osteoclast-like giant cells permeated with atypical oval and rounded mesenchymal cells in a fibrovascular stroma, cellular atypia, and scarce osteoid formation were observed. Immunohistochemistry revealed the Ki-67 proliferative index in 50% of positive cells, positivity for vimentin and CD68, as well as scarce positivity for CDK4. The patient's medical history involved a GCRO in the proximal ulna. This report highlights the aggressive behavior of GCRO and its high capacity for metastasis to different parts of the body. Clinicians, pathologists, and surgeons should be aware of the giant cell–rich variant of osteosarcoma of the jaws, an imminent “wolf in a sheep's skin”, because its indolent but unrelenting growth and dissemination, with radiographic and histologic characteristics that may represent a diagnostic pitfall regarding aggressive central giant cell lesions of the jaws.

Cryptococcosis is a neglected fungal disease. The scarcity of studies on oral cryptococcosis is certainly due to rarity and/or underreporting of the disease, especially in Brazil. We describe an example of orofacial cryptococcosis affecting a 57-year-old man after heart transplantation, who presented with multiple erythematous ulcers and erosions distributed in the chin, nasal cavity, labial mucosa, hard palate, and buccal vestibule. Computed tomography revealed opacities and micronodules in the lungs. Histopathological features of the oral and pulmonary lesions were compatible with Cryptococcus spp. Amphotericin B and fluconazole were used for treatment during hospitalization and itraconazole for prolonged therapy after hospital discharge. The patient has been under follow up for 6 months without signs of disease. According to a review conducted in PubMed, Web of Science, Scopus, Embase, and LILACS for data analysis of oral cryptococcosis, 26 reports were described in the literature. Predilection for men was observed (85%), with a male:female ratio of 5.5:1. The mean age of the individuals was 49 ± 15.3 years. Oral cryptococcosis mostly presented as an ulcer ( n = 17). The palate and tongue were the most affected sites ( n = 9 for each). Amphotericin B was the primary therapy utilized in most patients. Seventeen (65%) individuals survived. Knowledge of the clinicodemographic aspects of oral cryptococcosis is important for clinicians in decision making and surveillance.

The present study analyzed the presence of artifacts in endodontically treated teeth restored with fiberglass posts (FP) cemented with different resin cements by means of cone beam computed tomography (CBCT) in order to evaluate the contrast-to-noise ratio (CNR). A total of 60 mandibular premolars were selected to assemble the phantoms in order to simulate a clinical situation. The teeth were allocated to 6 groups, in which G1, G2 and G3 were endodontically treated teeth restored with FP cemented with Nexus 3, Duo-Link, and Allcem Core resin cements, respectively; G4: endodontically treated teeth restored with FP; G5: teeth treated only endodontically; and G6: healthy teeth. Mean gray scale values were analyzed in the axial images of the cervical, middle and apical thirds of the post length. CNR analysis was conducted on all groups except G5 and G6. There was a statistically significant difference in the mean values of the middle third region regarding the groups analyzed (p=0.026). However, artifacts were observed in all studied groups. The statistical difference observed between the cervical and apical thirds when the groups were evaluated together did not characterize the absence of artifacts between the resin cements, even when only the FP was present. Consequently, the choice of a resin cement might be based on ease of handling, better working time, cost-effectiveness, activation modes, substrate conditions, and clinical aspects. In summary, image quality was found to be compromised by artifacts in the presence of FP through CBCT with or without the resin cements in the root canal. El presente estudio analizó la presencia de artefactos en dientes tratados endodónticamente restaurados con postes de fibra de vidrio (PFV) cementados con cementos de resina diferentes mediante tomografía computarizada de haz cónico (TCHC) para evaluar la relación contraste-ruido (RCR). Se seleccionaron un total de 60 premolares inferiores para realizar los fantomas con el fin de simular una situación clínica. Los dientes fueron asignados en 6 grupos, en los cuales los grupos G1, G2 y G3 fueron dientes tratados endodónticamente, restaurados con PFV y cementados con cementos de resina Nexus 3, Duo-Link y Allcem Core, respectivamente; G4: dientes tratados endodónticamente restaurados con PFV; G5: dientes tratados solo endodónticamente; y G6: dientes sanos. Se analizaron los valores medios de la escala de grises en las imágenes axiales de los tercios cervical, medio y apical de la longitud del poste. El análisis RCR se realizó en todos los grupos excepto G5 y G6. Hubo diferencia estadísticamente significativa en los valores medios de la región del tercio medio en relación a los grupos analizados (p=0,026). Sin embargo, se observaron artefactos en todos los grupos estudiados. La diferencia estadística observada entre los tercios cervical y apical cuando los grupos fueron evaluados juntos no caracterizó la ausencia de artefactos entre los cementos de resina, incluso cuando solo estaba presente el PFV. En consecuencia, la elección de un cemento de resina puede basarse en la facilidad de manejo, mejor tiempo de trabajo, rentabilidad, modos de activación, condiciones del sustrato y aspectos clínicos. En resumen, la calidad de la imagen se vio comprometida por artefactos en presencia de PFV a través de TCHC con o sin cementos de resina en el conducto radicular. O presente estudo analisou a presença de artefatos em dentes tratados endodonticamente e restaurados com pinos de fibra de vidro (PFV) cimentados com diferentes cimentos resinosos por meio de tomografia computadorizada de feixe cônico (TCFC) para avaliar a relação contraste-ruído (RCR). Um total de 60 pré-molares inferiores foram selecionados para confeccionar os fantomas a fim de simular uma situação clínica. Os dentes foram alocados em 6 grupos, nos quais G1, G2 e G3 foram dentes tratados endodonticamente e restaurados com PFV cimentados com os cimentos resinosos Nexus 3, Duo-Link e Allcem Core, respectivamente; G4: dentes tratados endodonticamente restaurados com PFV; G5: dentes tratados apenas endodonticamente; e G6: dentes hígidos. Os valores médios da escala de cinza foram analisados nas imagens axiais dos terços cervical, médio e apical do comprimento do pino. A análise da RCR foi realizada em todos os grupos, exceto G5 e G6. Houve diferença estatisticamente significativa nos valores médios da região do terço médio em relação aos grupos analisados (p=0,026). No entanto, artefatos foram observados em todos os grupos estudados. A diferença estatística observada entre os terços cervical e apical quando os grupos foram avaliados em conjunto não caracterizou a ausência de artefatos entre os cimentos resinosos, mesmo quando apenas o PFV estava presente. Consequentemente, a escolha de um cimento resinoso pode ser baseada na facilidade de manuseio, melhor tempo de trabalho, custo-benefício, modos de ativação, condições do substrato e aspectos clínicos. Em resumo, a qualidade da imagem foi comprometida por artefatos na presença de PFV através de TCFC com ou sem os cimentos resinosos no canal radicular.

Introduction: Since photobiomodulation therapy (PBMT) favors in vitro mesenchymal stem cell (MSC) preconditioning before MSC transplantation, increasing the proliferation of these cells without molecular injuries by conserving their characteristics, in the present in vitro study we analyzed the effect of PBMT on the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs). Methods: Irradiation with an InGaAIP Laser (660 nm, 10 mW, 2.5 J/cm(2) , 0.08 cm(2) spot size, and 10 s) was carried out. The cells were divided into four groups: CONTROL [cells grown in Dulbecco’s Modified Eagle Medium (DMEM)], OSTEO (cells grown in an osteogenic medium); PBMT (cells grown in DMEM+PBMT), and OSTEO+PBMT (cells grown in an osteogenic medium plus PBMT). The cell proliferation curve was obtained over periods of 24, 48 and 72 hours using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Osteogenic differentiation was analyzed by the formation of calcium nodules over periods of 7, 14 and 21 days. Morphometric analysis was performed to quantify the total area of nodular calcification. Results: The highest cell proliferation and cell differentiation occurred in the OSTEO+PBMT group, followed by the PBMT, OSTEO and CONTROL groups respectively, at the observed times (P

The use of photobiomodulation therapy (PBMT) in the prevention of oral mucositis (OM) in paediatric care has increased. In this article, we report data of paediatric oncology/haematopoietic stem cell transplantation (HSCT) patients treated with PBMT to prevent chemotherapy-induced OM. A retrospective study was conducted at a Brazilian referral service. Prophylactic PBMT was used in children and adolescents (≤ 17 years) following the protocol: InGaAIP, 660 nm, 100 mW, 2 J, 3.33 W/cm2, and 20 s per point. Demographic data and OM severity scores were assessed. A regression model tested the association between OM with prophylactic PBMT and antineoplastic therapy. A total of 148 individuals who had undergone 358 chemotherapy cycles were analysed. A higher occurrence of OM was observed in HSCT and osteosarcoma (OS) patients. Except for HSCT, OM was associated with methotrexate (MTX) use in all disease groups. PBMT significantly reduced OM severity in acute lymphoblastic leukaemia (ALL) and OS patients. OM grade was 3.16 and 5.45 times higher among individuals with ALL and OS, who had not undergone prophylactic PBMT compared with those who had undergone prophylactic PBMT (p < 0.001). PBMT prevented chemotherapy-induced OM. Individuals who used MTX and did not undergo prophylactic PBMT were at increased risk of OM.

Data on the occurrence and clinicopathological characteristics of actinic cheilitis (AC) and lip squamous cell carcinoma (LSCC) are well studied; however, they are based on studies limited to a single centre. Herein, we described the frequency of AC and LSCC submitted to microscopic examination from representative geographic regions of Brazil. A retrospective multicentre study was performed on biopsies obtained from 1953 to 2018 at 10 Brazilian oral and maxillofacial pathology centres. A total of 198,709 biopsy specimens were surveyed. Sociodemographic data and clinicopathologic characteristics were analysed. A total of 2017 cases of ACs (1.0%) and 850 cases of LSCCs (0.4%) were recorded. A strong fair-skinned (> 87%) male (> 70%) predilection was observed in both conditions. The mean age was 54.8 ± 18.7 for individuals with AC and 57.8 ± 19.0 for individuals with LSCC. The most commonly affected site was the lower lip (> 90%). This is a large multicentre study of AC and LSCC from Brazil. The frequency and clinicopathological features of AC and LSCC were similar to those described worldwide. This study provides robust and representative epidemiological data of these conditions for the scientific community.

We present the frequency of cases of isolated odontogenic keratocysts submitted to microscopic examination at 10 Brazilian referral centres in Oral and Maxillofacial Pathology. In a retrospective (1953-2017) analysis, data on clinicoradiographic features and treatment of these lesions were collected and analysed descriptively. Among the 258,867 cases retrieved, 2,497 (0.96%) were isolated odontogenic keratocysts. In summary, an overview of individuals affected with isolated odontogenic keratocysts is reported herein. This lesion showed predilection for the posterior mandible of young adult men.

A clear cell variant of calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm, accounting for 33 cases described in the literature. In this article, we report a challenging example of clear cell variant of calcifying epithelial odontogenic tumor of the posterior maxilla in a 45-year-old female patient showing locally aggressive growth and recurrence. Microscopically, islands of polyhedral cells containing abundant cytoplasm, well-developed intercellular bridges blended with clear cells were observed. The nuclei were frequently pleomorphic and permeated by hyaline calcified material. Immunohistochemistry revealed positivity for pan-cytokeratin (AE1/AE3), cytokeratins (CK-14 and CK-19), Bcl-2, p53, and p63. The Ki-67 proliferative index was ~10%. As odontogenic tumors are rare, when a significant clear cell component is observed, the differential diagnosis with other lesions of the jaws with similar morphology, including other odontogenic tumors with prominent clear cell component, clear cell odontogenic carcinomas, and metastatic tumors, is difficult.