ABSTRACT: COVID-19 is a profound, highly contagious and life-threatening viral disease that will be with us for a long time. Health Care-related professions and life in its entirety are significantly, and perhaps irreversibly affected, all around the World. COVID-19 is and will continue to transform Dentistry and its practise. Based on the available evidence accrued to date, this work attempts to address such changes, current and anticipated, as well as present recommendations for clinical practise implementation, tailored for Latin/South America, in light of such lifealtering momentous pandemic.

RESUMEN: COVID-19 es una enfermedad altamente contagiosa y potencialmente mortal que nos acompañara por largo tiempo. Las profesiones de la salud y la vida en general ha sido afectada de forma significativa en todo lugar del mundo. La odontología ha pasado de una etapa de gran desarrollo clínico a una etapa donde el manejo de barrera de protección, el control de tratamientos y el tiempo asignado a los pacientes cambiará la forma de realizar la profesión. El presente trabajo pretende resumir las indicaciones y recomendaciones basadas en la evidencia disponible y realizar un análisis de la condiciones de salud oral para Latinoamérica en esta época de pandemia.

ABSTRACT Spindle cell carcinoma (SCC) is a rare variant of squamous cell carcinoma characterized by elongated and pleomorphic epithelial cells that resemble a sarcoma. Due to its rareness, and histological resemblance to various sarcomas, the diagnosis of this neoplasia is challenging. Herein we present the case of an 82-year-old female with a polypoid, ulcerated, soft tissue mass located on the left side of the maxilla. The tomographic examination showed a hyperdense mass that infiltrated the orbital cavity, ethmoidal cells, middle and lower nasal concha, maxillary sinus, zygomatic arch, and mandibular ramus on the left side. Histopathologically, the tumor was composed of spindle cells that were sarcomatous in appearance, with aberrant mitosis, along with a group of pleomorphic cells with a more epithelioid and hyperchromatic appearance on a stroma of densely vascularized fibrous tissue. The immunohistochemistry panel used to determine the lineage of the tumor rendered the diagnosis of SCC. The diagnosis of SCC is challenging to the pathologist since its morphology can resemble a sarcoma. Thus, immunohistochemistry is a valuable resource to support the diagnosis. We propose that SCC should be considered when examining a biphasic neoplasm with the aforementioned histological characteristics and markers.

Resumen: Con el fin de tener una mayor comprensión sobre el comportamiento biológico del mixoma odontogénico (MO), se realizó inmunohistoquímica en 31 muestras, utilizando marcadores relacionados con mecanismos de progresión tumoral (adhesión, angiogénesis, apoptosis, inflamación y proliferación celular). Epitelio odontogénico fue detectado en cuatro muestras mediante CK19 y CD138, este último, mostró expresión baja en matriz extracelular (MEC) y alta en las células tumorales. La microdensidad vascular (MDV) media fue de 7.51 y 5.35 vasos marcados con CD34 y VEGF-A respectivamente. Una alta expresión de Orosomucoide-1 y Mast Cell Tryptase se observó células tumorales y en MEC. El MO mostró negatividad para Calretinina. Este perfil inmunohistoquímico, la baja expresión para Ki-67, Bcl-2 y p53, y la relativamente baja MDV, sugieren que la actividad proliferativa, anti-apoptótica o angiogénica no representan los principales mecanismos de crecimiento del MO, los cuales podrían estar asociados a eventos como inmunomodulación y degradación de la MEC.

Abstract: In order to elucidate better the biological behavior of the odontogenic myxoma (OM), immunohistochemistry was performed in 31 samples, using markers related to mechanisms of tumor progression (adhesion, angiogenesis, apoptosis, inflammation and cell proliferation). Odontogenic epithelium was detected in four samples with CK19 and CD138, the latter had a low-expression in extracellular matrix (ECM) and a high-expression in tumor cells. The mean microvascular density (MVD) assessed with CD34 and VEGF-A, was 7.51 and 5.35 blood vessels respectively. A high-expression of Orosomucoid-1 and Mast Cell Tryptase was observed in tumor cells and ECM, while Calretinin was completely negative. The previously mentioned immunohistochemical profile, as well as the low expression of Ki-67, Bcl-2 and p53 and the relatively low MVD, suggests that the proliferative, anti-apoptotic and angiogenic activities do not represent the main growing mechanisms of OM, which could be associated to other events, such as immunomodulation and ECM degradation.

Resumo: Para melhor compreensão do comportamento biológico do mixoma odontogênico (MO), imuno-histoquímica foi realizada em 31 amostras, utilizando marcadores relacionados aos mecanismos de progressão tumoral (adesão, angiogênese, apoptose, inflamação e proliferação celular). Epitélio odontogênico foi detectado em quatro amostras por CK19 e CD138, o último mostrou baixa expressão na matriz extracelular (MEC) e alta em células tumorais. A microdensidade vascular (MDV) média foi de 7.51 e 5.35 vasos marcados com CD34 e VEGF-A, respectivamente. Uma alta expressão de Orosomucoide-1 e Mast Cell Tryptase foi observada nas células tumorais e na MEC. O MO mostrou negatividade para Calretinina. O perfil imuno-histoquímico mencionado acima, a baixa expressão de Ki-67, Bcl-2 e p53 e a relativamente baixa MDV, sugerem que a atividade proliferativa, anti-apoptótica ou angiogênica não representam os principais mecanismos de crescimento do MO, os quais poderiam estar associados com eventos como imunomodulação e degradação da MEC.

Resumo O objetivo deste estudo foi determinar se a distribuição das células de Langerhans (CL) e das células dendríticas intersticiais (CDI) está alterada no sarcoma de Kaposi oral associado à AIDS quando comparado às lesões orais altamente vasculares HIV-negativas. 51 casos de sarcoma de Kaposi oral associado à AIDS e 20 de lesões orais altamente vasculares foram recuperados retrospectivamente. Todos os casos de sarcoma de Kaposi foram confirmados pela positividade para os anticorpos CD34 e HHV-8. Dados clínicos sobre sexo, idade e localização das lesões foram obtidos dos laudos histopatológicos. Foram realizadas imunoistoquímica contra CD207 (células dendríticas imaturas) e CD83 (células dendríticas maduras). As CL estavam presentes no epitélio enquanto as CDI estavam presentes no estroma. As células CD207+ predominaram no epitélio das lesões, enquanto as células CD83+ predominaram no estroma. O sarcoma de Kaposi teve uma contagem mais baixa de CD imaturas CD207+ (p = 0,02) e número aumentado de CDC CD207+ do que lesões orais altamente vasculares (p<0,001). Além disso, o sarcoma de Kaposi também mostrou um número aumentado de CDI CD83+ maduras do que lesões orais altamente vasculares (p<0,001). Houve alterações significativas na distribuição de CL e CDI no sarcoma de Kaposi associado à AIDS quando comparado às lesões orais vasculares HIV-negativas, sugerindo que alterações na distribuição das mesmas podem desempenhar um papel na patogênese do sarcoma de Kaposi.

Abstract The aim of this study was to determine if the distribution of Langerhans cells (LC) and interstitial dendritic cells (IDC) is altered in AIDS-associated oral Kaposi’s sarcoma when compared to HIV-negative highly vascular oral lesions. Fifty-one cases of AIDS-associated oral Kaposi’s sarcoma and 20 of highly vascular oral lesions were retrospectively retrieved. All cases of Kaposi’s sarcoma were confirmed with immunoreactions against CD34 and HHV-8. Clinical data regarding sex, age and lesions location were obtained from pathology reports. Immunohistochemistry against CD207 (immature dendritic cells) and CD83 (mature dendritic cells) were done. LC were in the epithelium and IDC in the stroma. CD207+ cells predominated in the epithelium of the lesions, whereas CD83+ cells predominated in their stromal compartment. Kaposi’s sarcoma had a lower CD207+ immature LC count (p=0.02) and an increased CD207+ IDC than highly vascular oral lesions (p<0.001). Moreover, Kaposi’s sarcoma also showed an increased number of mature CD83+ IDC than highly vascular oral lesions (p<0.001). There were significant alterations in the distribution of LC and IDC in AIDS-associated Kaposi’s sarcoma when compared to HIV-negative vascular oral lesions, suggesting that changes in their concentrations may play a role in the pathogenesis of Kaposi’s sarcoma.

ABSTRACT: Oral melanoma (OM) is an extremely rare and aggressive malignancy. A 67-year-old patient presented with complains of a slightly symptomatic spot in the mouth since the past 2 years. Extraoral examination revealed left cervical lymphadenopathy, and intraoral examination a blue-black multinodular sessile mass, with irregular margins, involving the attached gingiva of teeth 27 and 28, extending to vestibular sulcus and hard palate, measuring approximately 3.5 cm. The lesion presented focal areas of ulceration. Panoramic radiograph did not show bone involvement. The main diagnostic hypothesis was oral melanoma. Microscopic findings of the incisional biopsy revealed a proliferation of densely pigmented pleomorphic cells, invading the subepithelial connective tissue in sheets or nests showing an organoid pattern. Immunopositivity for S-100, Melan-A and HMB-45 confirmed the diagnosis of melanoma. The patient was referred to an oncology hospital in which multiple metastases were detected, and the patient was subjected to palliative care. Herein we report an OM in advanced clinical stage, and discuss the clinical, morphological and immunohistochemical diagnostic criteria with emphasis on the importance of early diagnosis.

RESUMEN: El melanoma oral (MO) es una malignidad extremadamente rara y agresiva. Un paciente de 67 años acudió a consulta con la queja de una mancha intraoral ligeramente sintomática, presente desde hace dos años. Al examen clínico extraoral, se encontró adenopatía cervical del lado izquierdo, y al examen intraoral, se observó una masa sésil multinodular de color negro azulado, focalmente ulcerada, con bordes irregulares, afectando la encía de los dientes 27 y 28, extendiéndose hasta el surco vestibular y el paladar duro, midiendo aproximadamente 3,5 cm. La radiografía panorámica no mostró involucramiento óseo. La principal hipótesis diagnóstica fue MO. Los hallazgos microscópicos de la biopsia incisional revelaron una proliferación de células pleomórficas densamente pigmentadas, invadiendo difusamente el tejido conectivo en forma de sábanas o nidos con patrón organoide. La positividad inmunohistoquímica para S-100, Melan-A y HMB-45 confirmó el diagnóstico de melanoma. El paciente fue referido a un hospital oncológico, en el cual se le detectaron múltiples metástasis y fue sometido a cuidados paliativos. Este es el reporte de un caso de MO diagnosticado en estado avanzado, en el que se discuten los criterios clínicos, morfológicos e inmunohistoquímicos para su diagnóstico, haciendo énfasis en la importancia del diagnóstico temprano.

Resumo Tumor glômico é uma neoplasia benigna composta de uma proliferação perivascular de células glômicas que lembram o corpo glômico normal. Usualmente, ele se apresenta como um nódulo pequeno, solitário, sintomático e azul-avermelhado, localizado na derme profunda ou subcutânea de extremidades superiores ou inferiores de adultos jovens e de meia-idade. Casos afetando a cavidade oral são muito raros, com apenas 23 casos bem documentados relatados na literatura de língua Inglesa. A seguir, nós apresentamos um caso raro de tumor glômico do lábio superior, e revisão da literatura dos casos envolvendo a boca.

Abstract Glomus tumor is a benign neoplasm composed of a perivascular proliferation of glomic cells that resembles the normal glomus body. Usually, it appears as a solitary, symptomatic small blue-red nodule, located in the deep dermis or subcutis of upper or lower extremities of young to middle-aged adults. Cases affecting the oral cavity are very rare, with only 23 well-documented cases reported in the English-language literature. Herein, we present a rare case of glomus tumor of the upper lip, and review the literature of cases involving the mouth.