11p15 Epimutations in Pediatric Embryonic Tumors: Insights from a Methylome Analysis.

Embryonic tumors share few recurrent mutations, suggesting that other mechanisms, such as aberrant DNA methylation, play a prominent role in their development. The loss of imprinting (LOI) at the chromosome region 11p15 is the germline alteration behind Beckwith-Wiedemann syndrome that results in an increased risk of developing several embryonic tumors. This study analyzed the methylome, using EPIC Beadchip arrays from 99 sporadic embryonic tumors. Among these tumors, 46.5% and 14.6% presented alterations at imprinted control regions (ICRs) 1 and 2, respectively. Based on the methylation levels of ICR1 and ICR2, four clusters formed with distinct methylation patterns, mostly for medulloblastomas (ICR1 loss of methylation (LOM)), Wilms tumors, and hepatoblastomas (ICR1 gain of methylation (GOM), with or without ICR2 LOM). To validate the results, the methylation status of 29 cases was assessed with MS-MLPA, and a high level of agreement was found between both methodologies: 93% for ICR1 and 79% for ICR2. The MS-MLPA results indicate that 15 (51.7%) had ICR1 GOM and 11 (37.9%) had ICR2 LOM. To further validate our findings, the ICR1 methylation status was characterized via digital PCR (dPCR) in cell-free DNA (cfDNA) extracted from peripheral blood. At diagnosis, we detected alterations in the methylation levels of ICR1 in 62% of the cases, with an agreement of 76% between the tumor tissue (MS-MLPA) and cfDNA methods. Among the disagreements, the dPCR was able to detect ICR1 methylation level changes presented at heterogeneous levels in the tumor tissue, which were detected only in the methylome analysis. This study highlights the prevalence of 11p15 methylation status in sporadic embryonic tumors, with differences relating to methylation levels (gain or loss), location (ICR1 or ICR2), and tumor types (medulloblastomas, Wilms tumors, and hepatoblastomas).

Clinical manifestations of head and neck cancer in pediatric patients, an analysis of 253 cases in a single Brazilian center

Background: Pediatric head and neck cancer (PHNC) is rare and its nonspecific clinical manifestations may often lead to delayed diagnosis. We aimed to describe the signs, symptoms, and clinicopathological characteristics of PHNC. Material and Methods: Medical records were retrospectively reviewed for all PHNC cases diagnosed from 1986 to 2016 affecting patients aged 19-years and younger from a tertiary referral center in Brazil. Demographic variables, anatomical site of primary tumors, histopathological diagnoses, signs and symptoms, and patterns of misdiagnosis were collected and interpreted by statistical and descriptive analysis. Results: A total of 253 PHNC cases were included. The mean age was 9.3 years and male patients were more frequently affected (60.9%). Burkitt lymphoma (23.7%), nasopharyngeal carcinoma (15.8%), and rhabdomyosarcoma (15.4%) were the most common cancer types. The nasopharynx (28.9%), cervical/lymph node region (25.3%), and craniofacial bones (8.3%) were the predominant anatomical sites. Tumor/swelling (68.4%), was the clinical finding often presented. The univariable analysis showed association between tumor histology and clinical variables such as sex (p=0.022), age (p<0.0001), anatomical location (p<0.0001) tumor/swelling (p=0.034), pain (p=0.031), systemic/general manifestations (p=0.004), nasal/breathing alterations (p=0.012), orbital/ocular alterations (p<0.0001). Misdiagnosis such as tonsillitis, otitis, and abscess were frequent. Conclusions: Although the clinical findings of PHNC are often unspecific, this study provided signs and symptoms with significant correlations between tumor histology. The suspicion of malignancy should be considered when the main signs and symptoms reported here appear and persist, in order to conduct a timely diagnosis.(AU)

Burkitt lymphoma of the head and neck: An international collaborative study.

BACKGROUND: Burkitt lymphoma (BL) is an aggressive B-cell lymphoma with three variants (endemic, sporadic, and immunodeficiency-associated), presenting with specific epidemiological and clinical features. Burkitt lymphoma affects the head and neck region (BLHN) in approximately 10% of cases. The aim of this study was to undertake a comparative analysis of the clinicopathologic and immunohistochemical (IHC) features of BLHN diagnosed in patients from Africa, Guatemala, and Brazil. METHODS: Cases diagnosed as BLHN were collected from the files of six oral pathology laboratory services (Brazil, South Africa, and Guatemala) and one Brazilian pediatric oncology hospital from 1986 to 2020. Clinicopathological and IHC data, and Epstein-Barr virus (EBV) status by in situ hybridization data for each case were reviewed and described. RESULTS: Of the 52 cases, BLHN was predominant in pediatric patients [43 (82.69%)] and males [43 (82.69%)], with a mean age of 11.26 ± 9.68 years (range, 1-39 years). Neck and cervical lymph nodes [14 (26.92%)], and involvement of both maxilla and mandible [8 (15.38%)], were the most common anatomical sites. Clinically, tumor/swelling [40 (31.25%)], cervical lymphadenopathy [14 (10.94%)], pain [12 (9.38%)], and bone destruction [12 (9.38%)] were frequent findings. All cases showed typical morphological characteristics of BL. IHC profiles included positivity for CD20 [52 (100%)], CD10 [38 (79.17%)], Bcl6 [29 (87.88%)], and c-Myc protein [18 (81.82%)]. EBV was positive in 18 cases (62.07%). The Ki-67 index ranged from 90 to 100%. CONCLUSION: The clinicopathological and EBV profile of BLHN in South African, Guatemalan, and Brazilian patients is similar.

Clinical, demographic, anatomopathological, and molecular findings in patients with medulloblastoma treated in a single health facility / Achados clínicos, demográficos, anatomopatológicos e moleculares de portadores de meduloblastoma tratados em uma única instituição

ABSTRACT Objective: To describe the clinical, demographic, anatomopathological, molecular, and survival characteristics of patients with medulloblastoma. Methods: Retrospective study based on patient information obtained from the review of medical records. Overall and event-free survival were analyzed using the Kaplan-Meier estimator, and the curves were compared by the log-rank test. Results: Among the patients investigated, 70 were male (66%), and age at diagnosis ranged from 2 months to 22 years. The most frequent signs and symptoms were headache (80.8%) and vomiting (75.8%). Regarding treatment, most patients (63.2%) underwent complete surgical resection, with a predominance of classic histology (63.2%). The 5-year overall survival rate was 67.9%, and the 10-year rate was 64.2%. Patients with molecular profile characteristic of the wingless (WNT) subgroup had a better prognosis, with 5-year overall survival of 75%. Conclusions: The clinical, demographic, anatomopathological, and molecular characteristics of patients with medulloblastoma described in the present study were mostly similar to those reported in the literature. Patients submitted to complete tumor resection had better clinical outcomes than those who underwent incomplete resection/biopsy. Patients classified as high-risk showed worse overall and event-free survival than those in the standard-risk group, and the presence of metastasis at diagnosis was associated with recurrence.

RESUMO Objetivo: Descrever as características clínicas, demográficas, anatomopatológicas, moleculares e de sobrevida de pacientes portadores de meduloblastoma. Métodos: Estudo retrospectivo, no qual as informações dos pacientes foram obtidas pela revisão dos prontuários médicos. Análises de sobrevida global e de sobrevida livre de eventos foram realizadas por meio da construção de curvas de Kaplan-Meier e a comparação entre as curvas foi feita pelo teste log-rank. Resultados: Entre os pacientes analisados, 70 pertenciam ao sexo masculino (66%) e a idade ao diagnóstico variou de dois meses a 22 anos. Os sinais e sintomas de maior frequência foram cefaleia (80,8%) e vômitos (75,8%). Em relação ao tratamento, a maioria (63,2%) dos pacientes foi submetida à ressecção cirúrgica total e apresentava como histologia predominante a forma clássica (63,2%). A taxa de sobrevida global em cinco anos foi de 67,9% e, em 10 anos, de 64,2%. Os pacientes com perfil molecular característico do subgrupo wingless (WNT) apresentaram melhor prognóstico, com sobrevida global em cinco anos de 75%. Conclusões: As características clínicas, demográficas, anatomopatológicas e moleculares dos pacientes com meduloblastoma descritas no presente estudo foram majoritariamente semelhantes às descritas na literatura. Pacientes submetidos à ressecção completa do tumor tiveram melhor evolução clínica do que aqueles com ressecção incompleta/biópsia. Pacientes estratificados como de alto risco apresentaram pior sobrevida global e livre de eventos do que o grupo standard e a presença de metástases ao diagnóstico se mostrou associada à ocorrência de recidiva da doença.

CLINICAL, DEMOGRAPHIC, ANATOMOPATHOLOGICAL, AND MOLECULAR FINDINGS IN PATIENTS WITH MEDULLOBLASTOMA TREATED IN A SINGLE HEALTH FACILITY.

OBJECTIVE: To describe the clinical, demographic, anatomopathological, molecular, and survival characteristics of patients with medulloblastoma. METHODS: Retrospective study based on patient information obtained from the review of medical records. Overall and event-free survival were analyzed using the Kaplan-Meier estimator, and the curves were compared by the log-rank test. RESULTS: Among the patients investigated, 70 were male (66%), and age at diagnosis ranged from 2 months to 22 years. The most frequent signs and symptoms were headache (80.8%) and vomiting (75.8%). Regarding treatment, most patients (63.2%) underwent complete surgical resection, with a predominance of classic histology (63.2%). The 5-year overall survival rate was 67.9%, and the 10-year rate was 64.2%. Patients with molecular profile characteristic of the wingless (WNT) subgroup had a better prognosis, with 5-year overall survival of 75%. CONCLUSIONS: The clinical, demographic, anatomopathological, and molecular characteristics of patients with medulloblastoma described in the present study were mostly similar to those reported in the literature. Patients submitted to complete tumor resection had better clinical outcomes than those who underwent incomplete resection/biopsy. Patients classified as high-risk showed worse overall and event-free survival than those in the standard-risk group, and the presence of metastasis at diagnosis was associated with recurrence.

Global frequency and distribution of head and neck cancer in pediatrics, a systematic review.

BACKGROUND: Incidence and mortality rates of childhood cancer represent a global public health issue, however, the worldwide prevalence of head and neck cancer in pediatric patients (HNCPP) is still unknown. Therefore, this study aimed to describe the frequency and distribution of HNCPP worldwide. METHODS: A specific search strategy was performed using MEDLINE, Scopus, and EMBASE to include studies based on hospital records, national cancer registries, and pathology files. Studies quality was assessed using the risk of bias checklist of the Joanna Briggs Institute Critical Appraisal. RESULTS: Nineteen publications (15,970 cases) were included. Global frequency ranged from 0.25 % to 15 %. Male patients older than 10 years of age were most affected by lymphomas, followed by carcinomas and sarcomas. Non-Hodgkin lymphoma, Hodgkin lymphoma, rhabdomyosarcoma, thyroid carcinoma, and nasopharyngeal carcinoma were the main histopathological subtypes. Neck/lymph nodes were anatomical hotspots. CONCLUSIONS: This HNCPP global overview may guide secondary prevention strategies and future etiological studies.

Oral and maxillofacial cancer in pediatric patients: 30 years experience from a Brazilian reference center.

OBJECTIVE: The aim of this study is to determine the relative frequency, demographic distribution and clinicopathological features of pediatric oral and maxillofacial cancer (POMC). METHODS: Medical records were retrospectively reviewed for all cancer cases diagnosed from 1986 to 2016 affecting patients aged 19 years and younger. Demographic variables, anatomical site, and histopathological diagnoses were collected and analyzed by descriptive statistics. RESULTS: Fifty-five (0.77%) POMCs were found among 7181 pediatric malignancies. Mean age at diagnosis was 8 years and patients aged 5-9 years presented the higher prevalence of malignant tumors (40%). White male patients were more frequently affected (78.18% and 65.45%, respectively). The most common cancer type was lymphomas (52.73%) followed by sarcomas (27.27%) and carcinomas (20%). Burkitt lymphoma (32.73%), rhabdomyosarcoma (14.55%), diffuse large B-cell lymphoma (9.09%), and mucoepidermoid carcinoma (9.09%) were the most common histopathological diagnoses. The main affected anatomical site was the oropharynx (38.18%), followed by salivary glands (30.91%), maxillofacial bone (20%), and oral cavity (10.91%). CONCLUSION: POMC has a low incidence; however, highly aggressive tumors, such as lymphomas and sarcomas, are common in this scenario. A better knowledge about the clinicopathological distribution of POMC may contribute to early diagnosis and improve survival rates.

Demographic and clinicopathologic distribution of head and neck malignant tumors in pediatric patients from a Brazilian population: A retrospective study.

BACKGROUND: The incidence of pediatric head and neck cancer (PHNC) is increasing worldwide, especially when compared with childhood cancer in general. However, there is still a lack of knowledge about the demographic profile of such patients across the globe. Therefore, the aim of this study was to describe demographic, topographic, and histopathological features of PHNC patients from a single Brazilian institution. METHODS: Medical records were retrospectively reviewed for all cancer cases diagnosed from 1986 to 2016 affecting patients aged 19 years and younger. The demographic variables (age, gender, race), topographic aspects of primary tumors, and histopathological diagnoses were collected and analyzed by descriptive statistics. RESULTS: Three hundred and sixty-seven (5.11%) head and neck malignant tumors were found among 7181 pediatric cancers diagnosed in this period. Mean age at diagnosis was 9.35 years with male (65.67%) predominance. Patients between the age group of 10-14 years presented the higher prevalence of malignant tumors. In terms of race, 73.02% of the patients were white and 9.54% were black. The main affected anatomic site was the neck and lymph nodes (41.42%), followed by nasopharynx (22.89%) and thyroid gland (6.54%). The most common cancer type was lymphoma (52.86%), followed by carcinoma (22.89%), and sarcoma (19.07%). Burkitt lymphoma, nodular sclerosis Hodgkin lymphoma, nasopharyngeal carcinoma, and rhabdomyosarcoma were the most common histopathological diagnoses (16.62%, 13.08%, 12.81%, and 12.81%, respectively). CONCLUSION: This study originally demonstrated that lymphomas may be more frequent than carcinomas and sarcomas in Brazilian PHNC patients.