Artificial intelligence and radiomics in the diagnosis of intraosseous lesions of the gnathic bones: A systematic review.

BACKGROUND: The purpose of this systematic review (SR) is to gather evidence on the use of machine learning (ML) models in the diagnosis of intraosseous lesions in gnathic bones and to analyze the reliability, impact, and usefulness of such models. This SR was performed in accordance with the PRISMA 2022 guidelines and was registered in the PROSPERO database (CRD42022379298). METHODS: The acronym PICOS was used to structure the inquiry-focused review question "Is Artificial Intelligence reliable for the diagnosis of intraosseous lesions in gnathic bones?" The literature search was conducted in various electronic databases, including PubMed, Embase, Scopus, Cochrane Library, Web of Science, Lilacs, IEEE Xplore, and Gray Literature (Google Scholar and ProQuest). Risk of bias assessment was performed using PROBAST, and the results were synthesized by considering the task and sampling strategy of the dataset. RESULTS: Twenty-six studies were included (21 146 radiographic images). Ameloblastomas, odontogenic keratocysts, dentigerous cysts, and periapical cysts were the most frequently investigated lesions. According to TRIPOD, most studies were classified as type 2 (randomly divided). The F1 score was presented in only 13 studies, which provided the metrics for 20 trials, with a mean of 0.71 (±0.25). CONCLUSION: There is no conclusive evidence to support the usefulness of ML-based models in the detection, segmentation, and classification of intraosseous lesions in gnathic bones for routine clinical application. The lack of detail about data sampling, the lack of a comprehensive set of metrics for training and validation, and the absence of external testing limit experiments and hinder proper evaluation of model performance.

Prognostic outcomes of oral squamous cell carcinoma derived from proliferative verrucous leukoplakia: A systematic review.

OBJECTIVE: This study aimed to evaluate prognostic outcomes of PVL-derived oral squamous cell carcinomas (P-OSCC) based on recurrence, new primary tumour, metastasis and survival information. STUDY DESIGN: Five databases and grey literature were searched electronically with the following main keywords (proliferative verrucous leukoplakia, squamous cell carcinoma and malignant transformation) to answer the following review question: 'Are survival outcomes for P-OSCC worse?' based on the PECOS principle. The Joanna Briggs Institute Critical Appraisal tool was used to identify possible biases and assess the quality of each of the primary studies. RESULTS: A total of 21 articles met the inclusion criteria, and the results of this systematic review suggest that P-OSCC can recur and generate new primary tumours; however, metastases are rare. Thus, most patients remain alive for an average period of 5 years. CONCLUSION: Apparently, P-OSCC has better clinical prognostic characteristics than conventional OSCC. There is a lack of information on the main prognostic outcomes of P-OSCC; therefore, specific studies must be performed to achieve a better comparison between P-OSCC and conventional OSCC progression.

To extract or not extract teeth prior to head and neck radiotherapy? A systematic review and meta-analysis.

PURPOSE: Teeth with poor prognosis are generally recommended to be extracted prior to head and neck radiotherapy (RT) to reduce the risk of developing osteoradionecrosis (ORN), although controversies have been reported. The present systematic review aimed to determine whether tooth extraction prior to head and neck RT may be associated with a reduced risk of developing ORN compared to dental extraction during or after RT. METHODS: The review protocol was registered in PROSPERO (CRD42021241631). The review was reported according to the PRISMA checklist and involved a comprehensive search of PubMed, Scopus, Embase, Cochrane Library, LILACS, and Web of Science, in addition to the gray literature. The selection of studies was performed in two phases by two reviewers independently. The risk of bias of individual studies was analyzed using the Joanna Briggs Institute checklist for cross-sectional studies, and the certainty of evidence was assessed using the GRADE tool. RESULTS: Twenty-eight observational studies were included in the qualitative synthesis, which showed substantial heterogeneity regarding the association between the timing of tooth extraction and ORN development. Twenty-seven of 28 studies were pooled in a meta-analysis that demonstrated a significant association between an increased risk of ORN and post-RT tooth extraction (odds ratio: 1.98; 95% CI: 1.17-3.35; p = 0.01). CONCLUSION: It was confirmed with moderate certainty that dental extractions should be performed prior to the start of head and neck RT to reduce the risk of ORN.

Impact of the COVID-19 pandemic on public University laboratories of oral and maxillofacial pathology: A Brazilian multicenter study.

OBJECTIVE: To evaluate the impact of the COVID-19 pandemic on the number of diagnoses of oral and maxillofacial lesions in public laboratories after one year of COVID-19 outbreak in Brazil. MATERIAL AND METHODS: This is a cross-sectional study. Biopsies submitted to histopathologic examination from March 2019 to February 2020 (pre-pandemic period) and from April 2020 to March 2021 (pandemic period) in nine Brazilian public oral pathology laboratories were retrieved and the number of diagnoses, types of lesion, and percentage changes during both periods were analyzed. RESULTS: There were 7389 diagnoses in the pre-pandemic period and 2728 in the pandemic era, indicating a reduction of 63.08%. The reduction was 64.23% for benign lesions and 49.48% for malignant lesions, with a 50.64% reduction in squamous cell carcinoma. The largest decreases were observed in April 2020 and January 2021. CONCLUSION: An important reduction in the diagnoses of benign and malignant lesions was noted in the Brazilian public oral pathology laboratories during the first year of the COVID-19 pandemic.

Acquired oral syphilis: A multicenter study of 339 patients from South America.

OBJECTIVE: To report the clinicopathologic features of acquired oral syphilis cases in South American countries. MATERIALS AND METHODS: Clinical data were retrospectively collected from the records of 18 oral diagnostic services in Argentina, Brazil, Chile, Colombia, Venezuela, Uruguay, and Peru. Serologies of nontreponemal and treponemal tests were used for diagnosis. RESULTS: The series comprised 339 cases of acquired oral syphilis. Secondary syphilis ranked as the most common stage (86.7%). Lesions were more frequent among males (58.0%) and young adults with a mean age of 33.3 years. Individuals aged 20-29 years were most affected (35.3%). The most commonly involved sites were the tongue (31.6%), lip/labial commissure (25.1%), and hard/soft palate (20.4%). Clinically, acquired oral syphilis usually presented as mucous patches (28.4%), papules (25.7%), and ulcers (18.1%). Skin manifestations occurred in 67.7% of individuals, while lymphadenopathy and fever were observed in 61.3% and 11.6% of all subjects, respectively. Most patients were treated with the benzathine penicillin G antibiotic. CONCLUSION: This report validates the spread of acquired oral syphilis infection among young adults in South America. Our directives include accessible diagnostic tools for proper disease screening, surveillance, and counselling of affected individuals, especially in low- and middle-income countries.

Clinicopathological analysis and survival outcomes of primary salivary gland tumors in pediatric patients: A systematic review.

BACKGROUND: Salivary gland tumors are a diverse group of uncommon neoplasms that are rare in pediatric patients. The aim of this study was to evaluate the clinicopathological profile and survival outcomes of pediatric patients affected by salivary gland tumors. MATERIALS AND METHODS: An extensive search was carried out using the MEDLINE/PubMed, EMBASE, Scopus databases, and grey literature. The risk of bias was available in all papers included. RESULTS: A total of 2,830 articles were initially retrieved with 54 remaining for data extraction, resulting in 2,937 cases. This comprised forty-five case series' and nine cohort studies. These tumors were slightly more prevalent in females (57.4%). The patients' age ranged from 0.3 to 19 years old, with a mean age of 13.3 years. Parotid was the most affected site (81.9%), and 99.2% of cases clinically exhibited a swelling. Presence of pain/tenderness was reported in 13.5% of the cases, with an average duration of 12.6 months for the appearance of symptoms. Most of the reported cases were malignant tumors (75.4%), with mucoepidermoid carcinoma the most common tumor of all tumors (44.8%), followed by pleomorphic adenoma (24.1%). Surgery alone was the leading treatment choice in 74.9% cases, and the 5-year overall survival rate of patients was 93.1%. Patients with symptoms (P = .001), local recurrence (P < .001), metastasis (P < .001), and those not undergoing surgery or surgery combined with radiotherapy (P < .001) showed lower survival rates. CONCLUSION: The pediatric patients present a high frequency of malignant salivary neoplasms and a high overall survival rate.

Prognostic value of CRTC1-MAML2 translocation in salivary mucoepidermoid carcinoma: Systematic review and meta-analysis.

The presence of the CRTC1-MAML2 translocation has been described in mucoepidermoid carcinoma (MEC) as a predictor of better survival rates. However, the real prognostic value of the translocation has been debated due to recent controversial findings. The aim of this study was to perform a systematic review to understand the prognostic potential of the CRTC1-MAML2 translocation in MEC. An electronic search was carried out using the MEDLINE/PubMed, EMBASE and Scopus databases. Articles that assessed the association between the CRTC1-MAML2 translocation and survival of MEC patients were selected for the systematic review. Ten published articles were included in the qualitative synthesis. The prevalence of the translocation varied from 33.7% to 69.7%. Seven studies observed a significant association between the presence of the CRTC1-MAML2 translocation and a favourable clinical outcome, which could improve disease-free, disease-specific or overall survival. Five studies were included in the quantitative synthesis. Fixed-effects model confirmed that translocation-positive patients have a decreased risk of death (combined odds ratio 0.08, 95% confidence interval - 0.03-0.23, P < .00001). The detection of the CRTC1-MAML2 translocation appears to be useful as a prognostic factor in MEC. However, the level of evidence is not as high as it could be once important limitations were found in the published studies.

An audit of cytopathology in the oral and maxillofacial region: 18 years of experience.

INTRODUCTION: The aim of this study was to perform an audit of oral and maxillofacial specimens submitted for cytological diagnosis to verify the importance of this complementary examination. METHODS: A retrospective analysis of our institutional cytopathology database was performed over an 18-year period. Clinical information and cytological data were collected. Associations between independent variables and outcomes were assessed using the Pearson χ2 test or Fisher's test, with a 5% significance level. When available, the histological diagnosis was compared with cytological diagnosis to identify the percentage of agreement and the specificity, sensitivity and accuracy of cytology in identifying malignant neoplasms. RESULTS: A total of 1082 cases were identified, which included 65 different cytological diagnoses. Exfoliative cytology (EC) was performed in 312 cases (29.1%) and fine needle aspiration cytology (FNAC) in 770 cases (70.9%). EC was mainly employed to diagnose oral infectious diseases (P < 0.001) and FNAC to diagnose neoplasms, cystic, reactive and miscellaneous lesions (P < 0.001). Cell-block was performed in 555 FNAC cases (51.3%). Panoptic, Papanicolaou and haematoxylin-eosin staining were performed in FNAC and periodic acid-Schiff in EC (P < 0.001). In 211 cases (19.5%), the histological diagnosis was available and the percentage agreement with the cytological diagnosis was 41.2%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to identify malignant neoplasms were 84.6%, 100%, 100%, 77.8% and 90.0%, respectively. CONCLUSIONS: EC was mainly performed for diagnosis of infectious diseases and FNAC for diagnosis of salivary gland tumours, odontogenic lesions, reactive lesions and cervical metastasis.

Intraoral Pleomorphic Adenoma in Young Patients.

BACKGROUND: Intraoral pleomorphic adenoma (PA) is rare in young individuals, with only single clinical reports or small patient series reported previously. AIM: The aim of this study was to describe the clinicopathological features of PA in 4 patients under 18 years of age, and to discuss the differential diagnosis of pediatric patients presenting with intraoral submucosal nodules. METHODS: Between 2000 and 2015, all patients of intraoral PA in patients aged ≤18 years diagnosed in the Oral Pathology Laboratory of the Universidade Federal de Pernambuco, Brazil, were retrieved for the study. Clinical data were recorded from the clinical charts. Histopathological slides stained with hematoxylin and eosin were reviewed to confirm the diagnosis. RESULTS: There were 4 cases of PA in patients aged ≤18 years. All patients in this patient series were males, with a mean age of 16.7 years. Three cases occurred in the palate, and in 1 case, the upper lip was affected. All PAs appeared as a painless, smooth surface, well-circumscribed, and submucosal nodule. All patients were surgically excised and subsequent histopathological analysis revealed well-circumscribed tumors composed of cells that were arranged in ducts within a fibromyxoid stroma. No signs of recurrence were observed in 3 patients after a mean follow-up of 30 months. One patient is lost to follow-up. CONCLUSION: Although PAs are unusual in young patients, they should be considered in the differential diagnosis of oral submucosal nodules.

Reported physical examination methods for screening of oral cancer and oral potentially malignant disorders: a systematic review.

OBJECTIVE: This systematic review aimed to describe the method followed during physical examination and the anatomical structures of the head and neck assessed in screening for oral cancer and oral potentially malignant disorders (OPMDs). STUDY DESIGN: An extensive literature search was carried out using MEDLINE/PubMed, EMBASE, Scopus, LILACS, Web of Science, Cochrane databases, and gray literature. The risk of bias was available in all papers included. RESULTS: Of 9,688 records identified, 27 were included in this review, reporting data from 356,250 individuals screened and distributed across 11 countries. Most of these (n = 19) were based on 1 round of screening conducted by a dental professional or other health care workers. Most screening programs included visual inspection and palpation of the lips, oral cavity, and the most visible oropharyngeal sites, but the descriptions reported were imprecise. Additional inspection and palpation of the neck (submental, submandibular, cervical, and supraclavicular regions) to assess for the presence of swellings and any palpable neck nodes were also performed in 15 programs. CONCLUSION: In conclusion, there was considerable heterogeneity in the method of physical examination in screening programs for oral cancer and OPMDs among the included studies.

Clinical and epidemiological profile of burning mouth syndrome patients following the International Headache Society classification: a systematic review and meta-analysis.

OBJECTIVE: This systematic review aimed to determine the clinical and epidemiologic profile of patients with burning mouth syndrome (BMS) following the current classification of the International Headache Society (IHS)-the International Classification of Headache Disorders (ICHD-3) and the International Classification of Orofacial Pain (ICOP). STUDY DESIGN: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and involved a comprehensive search on PubMed, Scopus, EMBASE, Web of Science, LILACS, and the gray literature. RESULTS: Of the 4,252 studies identified, 41 were included. In general, there were no differences between the clinical and epidemiologic profiles of patients with BMS classified based on ICHD-3 or ICOP. Studies were pooled in meta-analyses and showed a significant prevalence of female patients between the sixth and seventh decade of life. The burning sensation and the tongue were the most prevalent descriptors and affected location. Significant associations were demonstrated between BMS and anxiety (P = .0006), depression (P = .004), and poor oral hygiene (P = .00001). CONCLUSIONS: Under the existing contemporary classification systems, patients with BMS were found to be mostly females in the sixth and seventh decade of life with a burning sensation on the tongue. Experiencing depression and anxiety was a commonly existing comorbidity.

Prevalence and clinical characteristics of oral lesions in heart transplant patients induced by sirolimus and everolimus: a systematic review and meta-analysis on a global scale.

OBJECTIVE: Sirolimus (SRL) and everolimus (EVL) are increasingly included in immunosuppressive protocols after heart transplantation. They present some side effects, including the appearance of painful lesions in the oral cavity. Therefore, this systematic review aimed to verify the global prevalence and clinical characteristics of oral lesions induced by SRL and EVL in heart transplant patients. STUDY DESIGN: A systematic review was performed using 5 main electronic databases (Medline/PubMed, SCOPUS, EMBASE, Web of Science, and LILACS), in addition to the gray literature. Studies were independently assessed by 2 reviewers based on established eligibility criteria. The risk of bias was assessed using the Joanna Briggs Institute appraisal tools, and the certainty of evidence was evaluated through GRADE assessment. RESULTS: Seventeen studies (860 patients) were included in the qualitative analysis. Of these, 11 studies were pooled in a meta-analysis of prevalence. The worldwide prevalence of oral lesions induced by SRL and EVL in heart transplant patients was 10.0%, and most lesions were described as ulcers >1.0 cm, related to significant pain. CONCLUSIONS: Oral lesions induced by SRL and/or EVL, although not very prevalent, have a relevant impact on patient's lives and the continuity of treatment.

Cell block preparation as an adjunctive tool after fine-needle aspiration cytology for screening oral and maxillofacial diseases.

OBJECTIVE: To describe the use of cell block (CB) preparation from fine-needle aspiration cytology for diagnosing oral and maxillofacial diseases. STUDY DESIGN: We performed a retrospective analysis of 568 samples collected by our laboratory for CB preparation from fine-needle aspiration cytology of the oral and maxillofacial region between January 2001 and October 2021. We performed cytologic diagnoses and compared them with the available histopathologic diagnoses to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation for identifying malignant lesions. RESULTS: The most frequent diagnosis was pleomorphic adenoma (n = 44, 7.7%), followed by metastatic squamous-cell carcinoma (n = 28, 4.9%) and odontogenic keratocyst (n = 26, 4.6%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CB preparation, which revealed detailed morphologic and architectural patterns, were 70.0%, 100.0%, 100.0%, 62.5%, and 80.0%, respectively. CONCLUSIONS: Cell block preparation from fine-needle aspiration cytology of the oral and maxillofacial region may be a useful adjunctive diagnostic tool for diagnosing oral and maxillofacial diseases because it reveals morphologic and architectural patterns similar to those shown on histopathologic slides, leading to the better categorization of diseases.

Dosimetric parameters and radiotherapy simulation methods used in preclinical studies of radiation damage to the dentition: a systematic review.

OBJECTIVE: This systematic review investigated the dosimetric parameters used in preclinical studies. STUDY DESIGN: Searches were performed in 3 databases (PubMed, Scopus, and Embase) and gray literature to identify studies for review. In vitro and ex vivo studies that examined the effect of radiation on human permanent teeth were included. The modified Consolidated Standards Of Reporting Trials checklist of items for reporting preclinical in vitro studies was used to assess the risk of bias. RESULTS: In total, 32 studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and in ex vivo studies was 69 (±1) Gy. Twenty-two studies used 5 different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting. Twenty studies used linear accelerators, and 7 used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the storage solution for the dental structure used most commonly. Biases were observed, including small sample sizes, lack of randomization, and blinding processes. CONCLUSION: The dosimetric parameters used in the preclinical studies, including radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used did not support the hypothesis of direct effects of radiation on the dental structure.

Clinicopathological study and survival outcomes of sialoblastoma: A systematic review.

Sialoblastoma is a rare malignant salivary gland tumor. The aim of this study was to review the available published data on sialoblastoma in a comprehensive analysis of its clinicopathologic characteristics, treatment, and outcomes. An unrestricted electronic search was performed in the following databases: MEDLINE/PubMed, EMBASE, Scopus, Web of science, and gray literature databases. Eligibility criteria included publications with sufficient clinical, imaging, and histopathological information to confirm the diagnosis of sialoblastoma. Data were evaluated descriptively and analytically. A total of 52 studies met the eligibility criteria. In total, 62 patients were evaluated. There was no gender predilection, with the parotid being the most affected primary site (n = 28; 45.2%). In the log-rank test, there was a significant increase in disease-associated survival in patients younger than 1 year of age (82.8% vs. 44.4%; p = 0.003), individuals with lesions in major salivary glands (79.4% vs. 38.5%; p = 0.005), patients without metastases (77.8% vs. 14.3%; p = 0.011), encapsulated lesions (85.7% vs. 0%; p < 0.0001), congenital lesions (83.3% vs. 25.0%; p < 0.0001), and lesions that do not show perineural invasion (89.5% vs. 40%; p = 0.035). Kaplan-Meier curves estimated overall survival and disease-free survival at 5 years of 95.5% and 68.1%, respectively. In the multivariate Cox regression model, only the presence of metastasis was identified as an independent prognostic factor (hazard ratio [HR] = 9.81; p = 0.010). Although sialoblastoma presents good prognosis, the tumor has a high recurrence rate.

Machine learning for the prediction of toxicities from head and neck cancer treatment: A systematic review with meta-analysis.

INTRODUCTION: The aim of the present systematic review (SR) is to summarize Machine Learning (ML) models currently used to predict head and neck cancer (HNC) treatment-related toxicities, and to understand the impact of image biomarkers (IBMs) in prediction models (PMs). The present SR was conducted following the guidelines of the PRISMA 2022 and registered in PROSPERO database (CRD42020219304). METHODS: The acronym PICOS was used to develop the focused review question (Can PMs accurately predict HNC treatment toxicities?) and the eligibility criteria. The inclusion criteria enrolled Prediction Model Studies (PMSs) with patient cohorts that were treated for HNC and developed toxicities. Electronic database search encompassed PubMed, EMBASE, Scopus, Cochrane Library, Web of Science, LILACS, and Gray Literature (Google Scholar and ProQuest). Risk of Bias (RoB) was assessed through PROBAST and the results were synthesized based on the data format (with and without IBMs) to allow comparison. RESULTS: A total of 28 studies and 4,713 patients were included. Xerostomia was the most frequently investigated toxicity (17; 60.71 %). Sixteen (57.14 %) studies reported using radiomics features in combination with clinical or dosimetrics/dosiomics for modelling. High RoB was identified in 23 studies. Meta-analysis (MA) showed an area under the receiver operating characteristics curve (AUROC) of 0.82 for models with IBMs and 0.81 for models without IBMs (p value < 0.001), demonstrating no difference among IBM- and non-IBM-based models. DISCUSSION: The development of a PM based on sample-specific features represents patient selection bias and may affect a model's performance. Heterogeneity of the studies as well as non-standardized metrics prevent proper comparison of studies, and the absence of an independent/external test does not allow the evaluation of the model's generalization ability. CONCLUSION: IBM-featured PMs are not superior to PMs based on non-IBM predictors. The evidence was appraised as of low certainty.

Clinical outcomes of dental implants in head and neck cancer patients: An overview.

OBJECTIVE: The aim of this study was to evaluate the clinical outcomes of dental implants (DIs) in patients with head and neck cancer (HNC) treated with radiotherapy (RT), isolated chemotherapy, or bone modifying agents (BMAs). STUDY DESIGN: This study was registered in the Prospective Register of Systematic Reviews (CRD42018102772); conducted via the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist; and based on PubMed, Scopus, Embase, Cochrane Library, Web of Science, and gray literature searches. The selection of studies was performed in 2 phases by 2 independent reviewers. The risk of bias (RoB) was assessed by the Measurement Tool to Assess the Methodological Quality of Systematic Reviews 2. RESULTS: Twenty systematic reviews were included in the qualitative analysis. The majority scored as having high RoB (n = 11). Primary DIs placement in the mandible of patients with HNC subjected to RT doses <50 Gy was associated with better survival rates. CONCLUSIONS: The placements of DIs could be considered safe in patients with HNC in sites of alveolar bone that received RT (≤5000 Gy); however, no conclusions could be made in patients with cancer managed by chemotherapy or BMAs. Due to the heterogeneity of studies included, the recommendation for DIs placement in patients with cancer should be carefully considered. Future better controlled randomized clinical trials are required to provide enhanced clinical guidelines for best patient care.

Epithelial salivary gland tumors in pediatric patients: An international collaborative study.

OBJECTIVE: Salivary gland tumors (SGT) are a diverse group of uncommon neoplasms that are rare in pediatric patients. This study aimed to characterize the clinicopathological profile of pediatric patients affected by SGT from a large case series derived from an international group of academic centers. STUDY DESIGN: A retrospective analysis of pediatric patients with SGT (0-19 years old) diagnosed between 2000 and 2021 from Brazil, South Africa, and the United Kingdom was performed. SPSS Statistics for Windows was used for a quantitative analysis of the data, with a descriptive analysis of the clinicopathological characteristics and the association between clinical variables and diagnoses. RESULTS: A total of 203 cases of epithelial SGT were included. Females were slightly more commonly (56.5%), with a mean age of 14.1 years. The palate was the most common site (43.5%), followed by the parotid gland (29%), lip (10%), and submandibular gland (7.5%). The predominant clinical presentation was a flesh-colored, smooth, and painless nodule. Pleomorphic adenoma (PA) was the most frequently diagnosed SGT (58.6%), followed by mucoepidermoid carcinoma (MEC) (26.6%). Surgery (90.8%) was the favored treatment option. CONCLUSIONS: Benign SGT in pediatric patients are more commonly benign than malignant tumors. Clinicians should keep PA and MEC in mind when assessing nodular lesions of possible salivary gland origin in pediatric patients.