Odontogenic tumours in a Chilean population: a retrospective study of 544 cases based on 2022 WHO classification

Background: Odontogenic tumours are infrequent lesions. Studies on the frequency of odontogenic tumours from Latin America are scarce. This work aimed to determine the relative frequency of odontogenic tumours in a Chilean population using the 2022 World Health Organization classification. Material and Methods: This is a case series retrospective study. We reviewed 35,530 samples from 1975 to 2022 from the Oral Pathology Referral Institute and the Pathological Anatomy Service, Faculty of Dentistry, University of Chile. We utilized the 2022 World Health Organization classification for histological typification. Results: According to 2022 World Health Organization classification, 544 odontogenic tumours were confirmed. The most frequent odontogenic tumours were: odontoma (n=241; 44.3%), ameloblastoma (n=109; 20.0%) and cemento-ossifying fibroma (n=71; 13.1%). Benign odontogenic tumours corresponded to 538 cases (98.9%) and malignant tumours were only six cases (1.1%). Conclusions: In our population, odontoma was the most frequent odontogenic tumour followed by ameloblastoma and cemento-ossifying fibroma. Malignant odontogenic tumours were very rare. The results of this study are similar to reports from America, but there are some differences concerning the data from Africa and Asia. (AU)

Immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF and CD105 according to histological grading in oral squamous cell carcinoma / Expresión inmunohistoquímica de COX-2, Ki-67, Bcl-2, Bax, VEGF y CD105 según el grado histológico en el carcinoma oral de células escamosas

Introduction: Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck cancer. Few studies have analyzed the expression of proteins related to inflammation (COX-2) and tumor progression according to the histological grade of OSCC. Objective: Analyze the immunohistochemical expression of COX-2, Ki-67 (cell proliferation), Bcl-2/Bax (apoptosis), VEGF, and CD105 (angiogenesis) according to histological grades of OSCC.Material and methodsThe immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF, and CD105 of 58 cases of OSCC was analyzed. 13 cases of oral mucosa (OM) were analyzed as controls. Results: COX-2, VEGF, CD105, and Ki-67 were higher in OSCC than in OM, particularly in poorly differentiated OSCC (p<0.05). Bax expression was lower in poorly differentiated OSCC (p<0.001). The Bcl-2/Bax ratio was higher in OSCC compared to MO (p<0.05). Conclusion: There are immunohistochemical differences according to histological grades of OSCC, which could influence clinical behavior.(AU)

Introducción: El carcinoma oral de células escamosas (COCE) es el cáncer de cabeza y cuello más prevalente. Escasos estudios analizan la expresión de proteínas relacionadas a inflamación (COX-2) y progresión tumoral según el grado histológico de COCE. Objetivo: Analizar la expresión inmunohistoquímica de COX-2, Ki-67 (proliferación celular), Bcl-2/Bax (apoptosis), VEGF y CD105 (angiogénesis) según grados histológicos de COCE.Material y métodos. Se analizó la expresión inmunohistoquímica de COX-2, Ki-67, Bcl-2, Bax, VEGF y CD105 de 58 casos de COCE. Trece casos de mucosa oral (MO) fueron analizados como control. Resultados: Las expresiones de COX-2, VEGF, CD105 y Ki-67 fueron mayores en el COCE comparadas con la MO, particularmente en el COCE pobremente diferenciado (p < 0,05). La expresión de Bax fue menor en el COCE pobremente diferenciado (p < 0,001). La razón Bcl-2/Bax fue mayor en COCE comparado con MO (p < 0,05). Conclusión: Existen diferencias inmunohistoquímicas según grados histológicos de COCE, lo que podría determinar una evolución clínica diferenciada.(AU)

Immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF and CD105 according to histological grading in oral squamous cell carcinoma.

INTRODUCTION: Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck cancer. Few studies have analyzed the expression of proteins related to inflammation (COX-2) and tumor progression according to the histological grade of OSCC. OBJECTIVE: Analyze the immunohistochemical expression of COX-2, Ki-67 (cell proliferation), Bcl-2/Bax (apoptosis), VEGF, and CD105 (angiogenesis) according to histological grades of OSCC. MATERIAL AND METHODS: The immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF, and CD105 of 58 cases of OSCC was analyzed. 13 cases of oral mucosa (OM) were analyzed as controls. RESULTS: COX-2, VEGF, CD105, and Ki-67 were higher in OSCC than in OM, particularly in poorly differentiated OSCC (p<0.05). Bax expression was lower in poorly differentiated OSCC (p<0.001). The Bcl-2/Bax ratio was higher in OSCC compared to MO (p<0.05). CONCLUSION: There are immunohistochemical differences according to histological grades of OSCC, which could influence clinical behavior.

Aberrant immunoexpression of p53 tumour-suppressor and Bcl-2 family proteins (Bcl-2 and Bax) in ameloblastomas and odontogenic keratocysts.

Background: The growth of ameloblastomas (odontogenic tumours) and odontogenic keratocyst (OKC) (developmental cyst) is associated with the expression of proteins related to cell survival and apoptosis. Bcl-2-associated protein X (Bax) and the tumour suppressor protein p53 collectively promote p53-mediated apoptosis. This study aimed to assess the immunohistochemical expression of p53, Bcl-2 and Bax in conventional ameloblastoma (CA), unicystic ameloblastoma (UA) types, and OKC sporadic (OKC-NS/S) and syndromic (OKC-NBSCC). Material and Methods: Paraffinized blocks of CA (n=18), UA (n=15), OKC-NS/S (n=18) and OKC-NBSCC (n=15) fixed in 10% formalin were used. After diagnosis, tissue specimens were stained by immunohistochemistry for p53, Bcl-2 and Bax marker. Stained cells were randomly counted in five high power fields. The data analysis was performed via Shapiro-Wilk test, ANOVA with Tukey's multiple comparisons or Kruskal-Wallis with Dunn's multiple comparisons. Statistical significance was defined as p<0.05. Results: We did not observe differences between p53 expression in CA, mural UA (MUA), intraluminal/luminal UA (I/LUA), OKC-NS/S, and OKC-NBSCC (19.69%, 18.74%, 16.76%, 12.35% and 9.04%, respectively). Similar results were recognized for Bax expression in CA, MUA, I/LUA, OKC-NS/S, and OKC-NBSCC (33.72%, 34.95%, 22.94, 21.58% and 20.76%, respectively). However, we recognized significant differences between Bcl-2 expression in OKC-NS/S vs MUA, OKC-NS/S vs I/LUA, OKC-NS/S vs CA, OKC-NBSCC vs MUA, OKC-NBSCC vs I/LUA, and I/LUA vs CA. P53, Bcl-2 and Bax levels were higher in mural morphological areas versus intraluminal and luminal morphological areas in UA. Conclusions: There is a tendency for an increased expression of p53, Bcl-2, and Bax proteins in CA, and mural proliferation of UA, compared to lesions with a cystic morphology, which could be associated with a local aggressive behaviour. Key words:p53, Bcl-2, Bax protein, apoptosis, odontogenic tumour, odontogenic cyst.

Cyclooxygenase-2 protein expression modulates cell proliferation and apoptosis in solid ameloblastoma and odontogenic keratocyst. An immunohistochemical study.

BACKGROUND: Cyclooxygenase-2 protein is a critically important mediator in inflammation that influences proliferation, apoptosis, angiogenesis and metastasis. Previous works showed a relationship between cyclooxygenase-2 and tumourigenesis in humans and animal models. In epithelial odontogenic tumours and cysts, increased cell proliferation and survival have been linked to its pathogenesis and tumour development. The aim of the present study was to analyse the immunohistochemical expression of cyclooxygenase-2 in solid ameloblastoma and odontogenic keratocyst and its association with proteins related to cell proliferation and apoptosis. METHODS: This study was conducted on 40 cases from the Pathological Anatomy Service, University of Chile. The cases were diagnosed as solid ameloblastoma (n = 21) and odontogenic keratocyst (n = 19) according to WHO 2017. Slides prepared from paraffin-embedded sections were immunohistochemically stained for cyclooxygenase-2, cyclin D1, Ki-67, p63 and Bcl-2. Statistical evaluation was performed by the Shapiro-Wilk test, ANOVA Mann-Whitney test and Spearman's correlation coefficient (p < 0.05). RESULTS: There were significant differences in the immunoexpression of cyclin D1, Ki-67 and Bcl-2 between solid ameloblastoma and odontogenic keratocyst. Likewise, there was a significant difference in the immunoexpression of p63 between follicular and plexiform histological types/subtypes of solid ameloblastoma. Lastly, there were statistical associations between cyclooxygenase-2 and Ki-67 for solid ameloblastoma and between cyclooxygenase-2 and p63 for odontogenic keratocyst. CONCLUSION: A high level of cyclooxygenase-2 is related to increased cell survival and proliferative activity in solid ameloblastoma and odontogenic keratocyst. This event might contribute to tumoural progression and local invasiveness in these lesions.

Acute Promyelocytic Leukemia: A Long-Term Retrospective Study in Mexico.

BACKGROUND: The present retrospective study reviewed acute promyelocytic leukemia (APL) cases recorded in Mexico between January 2007 and January 2017. The primary objective of the study was to evaluate overall survival (OS) in Mexican patients with APL. Secondary objective was to evaluate the impact of induction treatment with different anthracyclines on OS, event-free survival (EFS) and complications in this patient population. METHODS: The medical charts of patients referred to medical institutions in Mexico from January 2007 through January 2017 for the treatment of suspected APL were reviewed retrospectively. Patients aged 15 - 75 years, in whom the diagnosis of APL was confirmed, who had an Eastern Cooperative Group performance status of 0 - 2, and who were eligible for combined treatment with intensive chemotherapy and all-trans retinoic acid (ATRA), were included in the study. Study participants received induction and consolidation treatment with ATRA plus either daunorubicin or idarubicin, followed by 2 years of single-agent ATRA as maintenance therapy. Patients who were unable to pay for ATRA treatment received anthracycline-based induction and consolidation, with methotrexate plus mercaptopurine as maintenance therapy. RESULTS: A total of 360 patients from 21 public and private hospitals were included in the study. The median age of the population was 37 years, and 51% were male. Of the 360 patients, 205 (57%) vs. 155 (43%) received daunorubicin vs. idarubicin as induction treatment for APL. ATRA was administered to 201 (98%) patients in the daunorubicin group vs. 138 (89%) in the idarubicin group (P = 0.001), and was initiated at diagnosis in 92% vs. 73% of recipients, respectively (P = 0.0001). At 150 months, OS and EFS for the entire population were 84% and 79%, respectively. Both OS (90% vs. 76%, P = 0.003) and EFS (85% vs. 72%, P = 0.001) were significantly prolonged in daunorubicin vs. idarubicin recipients. Rates of complications were similar in the two groups. CONCLUSIONS: As arsenic trioxide (ATO) is not currently available in Mexico, anthracycline plus ATRA is the mainstay of treatment for APL here. Our results confirm the efficacy of this strategy, with high OS and EFS rates being observed 12.5 years after diagnosis.

In situ preparation and osteogenic properties of bionanocomposite scaffolds based on aliphatic polyurethane and bioactive glass nanoparticles.

Bionanocomposite scaffolds based on aliphatic polyurethane (PU) and bioactive glass nanoparticles were produced by using a one-step in situ polymerization method. Bioactive glass nanoparticles (nBG) or mesoporous BG nanospheres (nMBG) were incorporated during the polymerization reaction to produce simultaneous formation and foaming of porous nanocomposite scaffolds. The in vitro bioactivity of the scaffolds was assessed in simulated body fluid (SBF), and through cytocompatibility and osteogenic differentiation assays with stem cells. Bone regeneration properties of the scaffold materials were in vivo assessed by using a critical-sized femoral defect model in rat. The scaffold nanocomposites showed excellent cytocompatibility and ability to accelerate the crystallization of bone-like apatite in vitro. nBG/PU bionanocomposite scaffold exhibited the higher capacity to stimulate osteogenic cell differentiation as judged by an increased ALP activity and the presence of mineralized nodules associated with the stem cells. nBG (5%)/PU scaffold significantly also produces in vivo a denser and more significant amount of new bone after 8 weeks of implantation, which is attributed to the more rapid dissolution rate of nBG into osteogenic ionic products compared to nMBG. The results of this work show that the in situ polymerization method combined with the use of nanodimensional BG particles enable the production of PU - based scaffolds with enhanced bioactive properties to stimulate the bone tissue regeneration.

Quiste odontogénico: análisis de 2.944 casos en Chile / Odontogenic Cysts: analysis of 2.944 cases in Chile

Introducción. Los quistes odontogénicos constituyen un grupo de frecuentes lesiones intraóseas propias de los maxilares y una de las principales causas de destrucción de estos huesos. En Chile no existen estudios retrospectivos del conjunto de estas lesiones.Objetivos. El propósito de este trabajo es determinar la frecuencia de estas lesiones diagnosticadas y registradas en el Instituto de Referencia de Patología Oral (IREPO) de la Universidad de Chile en dos grupos etáreos, así como analizar y comparar los datos obtenidos con aquellos publicados en otros estudios previos.Material y Método. Se revisaron los archivos del IREPO de la Facultad de Odontología de la Universidad de Chile correspondientesal período transcurrido entre 1976 y septiembre de 2004 y se determinó la frecuencia según edad, género y localización de cada una de estas entidades. Se hizo la comparación entre dos grupos etáreos (menor o igual a 15 años y mayores a 15 años). Los casos en que la información era insuficiente para ser analizada no fueron considerados. Todas las placas histológicas fueron reevaluadas de acuerdo a los criterios diagnósticos incluidos en la Tipificación Histológica de Tumores Odontogénicos de la OMS.Resultados. Se encontraron 2.944 quistes odontogénicos (QO), de los cuales 1.935 (65,7%) fueron quistes inflamatorios y 1.009 (34,3%) quistes del desarrollo. Con respecto al total de los quistes, hubieron 1.554 (52,8%) en hombres y 1.390 (47,2%) en mujeres. De las variedades reconocidas por la OMS, se encontraron la totalidad de ellas. Los quistes más frecuentes fueron: quistes radiculares 1.494 (50,7%); quistes dentígeros 546 (18,5%); queratoquistes 421 (14,3%) y quistes residuales 328 (11,1%). Estas cuatro variedades representan el 94,7% del total de los QO, con 2.789 casos. En población menor o igual a 15 años predominan los quistes del desarrollo (354) por sobre los quistes Inflamatorios (155), siendo los más frecuentes los quistes dentígeros con 240 casos

Introduction: Odontogenic cysts constitute a group of frequent intraosseous lesions characteristic in the maxillary bones and one of the main causes of the destruction of these bones. In Chile there are no retrospective studies of these lesions as a whole.Objective: The purpose of this study is to determine the frequency of these lesions in so far as they were diagnosed and registered in the Referral Institute for Oral Pathology (IREPO) of the University of Chile in two age groups as well as to analyze and to compare the data obtained with the data published in previous studies.Material and Method: We studied the records from IREPO of the University of Chile for the period between 1976 and September, 2004; and we determined the frequency according to age, gender and site of each of these lesions. We compare two age groups: younger than or equal to 15 years old and older than 15 years old. Those cases in which the information did not suffice for the purposes of analysis were not considered. All the histological slides were reclassiffed according to the diagnostic criteria included in the Histological Typification of the World Health Organization.Results: We found 2.944 odontogenic cysts (OC), of which 1.935 (65.7%) were inflammatory cysts and 1.009 were developmental cysts. Out of this total, there were 1.554 cysts (52.8%) in men and 1.390 (47.2%) in women. The most frequent cysts were 1.494 radicular cysts (50.7%), 546 dentigerous cysts (18.5%), 421 keratocysts (14.3%) and 328 residualcysts (11.1%).These four varieties represent 94.7% of the OC , that is, 2789 cases. In the population younger than or equal to 15 years of age the developmental cysts (354 cases) are more frequent than the inflammatory cysts (155 cases), the most frequent being dentigerous cysts (240 cases)

Odontogenic cysts: analysis of 2,944 cases in Chile.

INTRODUCTION: Odontogenic cysts constitute a group of frequent intraosseous lesions characteristic in the maxillary bones and one of the main causes of the destruction of these bones. In Chile there are no retrospective studies of these lesions as a whole. OBJECTIVE: The purpose of this study is to determine the frequency of these lesions in so far as they were diagnosed and registered in the Referral Institute for Oral Pathology (IREPO) of the University of Chile in two age groups as well as to analyze and to compare the data obtained with the data published in previous studies. MATERIAL AND METHOD: We studied the records from IREPO of the University of Chile for the period between 1976 and September, 2004; and we determined the frequency according to age, gender and site of each of these lesions. We compare two age groups: younger than or equal to 15 years old and older than 15 years old. Those cases in which the information did not suffice for the purposes of analysis were not considered. All the histological slides were reclassiffed according to the diagnostic criteria included in the Histological Typification of the World Health Organization. RESULTS: We found 2.944 odontogenic cysts (OC), of which 1.935 (65.7%) were inflammatory cysts and 1.009 were developmental cysts. Out of this total, there were 1.554 cysts (52.8%) in men and 1.390 (47.2%) in women. The most frequent cysts were 1.494 radicular cysts (50.7%), 546 dentigerous cysts (18.5%), 421 keratocysts (14.3%) and 328 residual cysts (11.1%). These four varieties represent 94.7% of the OC , that is, 2789 cases. In the population younger than or equal to 15 years of age the developmental cysts (354 cases) are more frequent than the inflammatory cysts (155 cases), the most frequent being dentigerous cysts (240 cases).

Odontogenic tumors in Chile: a study of 362 cases.

BACKGROUND: Odontogenic tumors are infrequent lesions. Thus, the review of a large number of cases becomes a necessity for both the pathologist and the clinician. Studies on odontogenic tumors have been published in many parts of the world, but there is little information available in the English language literature on the relative frequency of odontogenic tumors in Latin America. The aim of this study was to determine the relative frequency of this heterogeneous group of lesions in a Chilean population, and to compare these data with previous reports. METHODS: We reviewed the records of 28,041 specimens from 1975 to 2000 in the Oral Pathology Referral Institute (IREPO), and using the criteria for histological typification published by the World Health Organization in 1992, we reclassified the odontogenic tumors. RESULTS: We confirmed a total of 362 odontogenic tumors. The frequency of odontogenic tumors as a percentage of all pathological specimens in our institute was 1.29%. The most frequent histological type was odontomas (44.7%), followed by ameloblastomas (20.4%) and myxomas (8.8%). CONCLUSIONS: Odontogenic tumors are uncommon lesions in the Chilean population and malignant odontogenic tumors are very rare. The relative frequency of various types of odontogenic tumors, as well as the age and gender distribution are similar to those reported in the North American series and different from those found in recently published Asian and African series.

Respuesta inmune humoral de glándulas salivales menores en pacientes con parotiditis crónica recurrente / Humoral immunity response of minor salival glands in patients with chronic recurrent parotiditis

La parotiditis crónica recurrente inespecífica, es una enfermedad que afecta las glándulas parótidas de niños prepúberes, siendo de carácter inflamatorio. A pesar de ser la segunda enfermedad parotídea de mayor prevalencia en niños, no se sabe con certeza su etiología, y su tratamiento sigue siendo sólo paliativo. Dentro de las posibles etilogías que se proponen se encuentran algunas enfermedades de carácter inmune, es por esto que se investigó, si existían variaciones en la cantidad de inmunoglobulina G y M presente en las glándulas de estos niños. Para esto se tomó biopsias de glándulas salivales de labio inferior de niños enfermos y se sometieron a tinción inmunohistoquímica policlonal para IgG e IgM. Se realizó el conteo de los plasmocitos que presentaban IgG y M, comparándose con glándulas salivales menores sanas, sometidas a la misma tinción. Los resultados obtenidos permiten descartar, como causante de la enfermedad, respuestas anormales del sistema humoral, ya que la presencia de IgM e IgG no presentó diferencias significativas entre glándulas de pacientes enfermos y sanos