Comparación de inmunoexpresión de receptores CD68 en células gigantes y mononucleadas en lesiones central y periférica de células gigantes de los maxilares / A comparison of immunoexpression of CD68 receptors in giant cell and mononuclear cells of central and peripheral giant cell lesions of the jaws

Introducción: La lesión central (LCCG) y periférica (LPCG) de células gigantes de los maxilares, son lesiones reactivas con comportamiento clínico diferente. Objetivo: Comparar la inmunoexpresión de CD68 en células gigantes (CGm) mononucleares (CMn) en lesiones central y periférica de los maxilares. Material y métodos: Se evaluaron 35 casos de LCCG y 24 de LPCG en bloques de parafi na que podían ser procesadas para la expresión del anticuerpo CD68. La inmunoexpresión se valoró en el citoplasma de ambas poblaciones celulares, obteniendo proporciones; la inmunoexpresión se categorizó en intensa, moderada, leve. Las proporciones se compararon con χ2, siendo signifi cativo p ≤ 0.05. Resultados: Para las CGm de LCCG, CD68 se expresó en una proporción de 96 versus 84.2% LPCG (p < 0.005). La proporción de la tinción de la expresión intensa y moderada fue más frecuente en las LCCG (p = 0.032). Las proporciones entre las CMn 59.3% LCCG versus 18.6% en la LPCG (p < 0.001). Hubo diferencia en intensidad de CD68, en las CMn de LCCG fue mayor (p = 0.002). Conclusiones: La alta expresión de CD68 en las CGM y CMn en la lesión central y periférica confi rma su fenotipo de macrófago. Las diferencias entre las proporciones y la tinción a CD68 refl eja mayor actividad fagocítica posiblemente relacionada con el comportamiento clínico (AU)

Introduction: Central (CGCL) and Peripheral (PGCL) giant cell lesions of jaws are reactive lesions displaying diff erent behavior patterns. Objective: To compare CD68 immunoexpression between CGCL and PCGL in giant multinucleated and mononuclear cells. Material and methods: 35 CGCL and 24 PGCL were retrieved from paraffi n-embedded biopsy, as well as the feasibility to analyze CD68 immunoexpression. The immunoexpression was analyzed in cytoplasm both cell populations cellular, for and staining intensity was categorized as intense, moderate or faint. Proportions were compared by χ2, making a p ≤ 0.05 value signifi cate. Results: In 96% of CGCL's in GMCs displayed CD68, as compared to 84.2% in PGCL, (p < 0.005). The proportion of stained cells, intense to moderate staining was more frequent in CGCL (p = 0.032). The proportion CD68 was expressed in 59.3% or CGCL mononuclear cells, as compared to 18.6% in PGCL, (p < 0.001). There was diff erence in staining CD68 intensity between mononuclear cells in CGCL, (p = 0.002). Conclusions: The high CD68 expression frequency in GMCs and mononuclear cells in central and peripheral GCL confi rm a macrophage phenotype; a more intense staining in CGML and GMCs suggests a more active phagocytic activity, and possibility underline the diff erent clinical behavior (AU)

Estudo microscópico morfométrico e genotípico de pacientes portadores de lesão central de células gigantes / Microscopic morphometric and genotypic assessment of patients with central giant cell lesions

A lesão central de células gigantes (LCCG) é uma afecção benigna dos maxilares, de comportamento biológico incerto, variando de discreta tumefação assintomática e de crescimento lento à uma forma agressiva, associada a dor, reabsorção radicular e óssea, com destruição cortical. Sua etiologia permanece desconhecida, havendo controvérsias entre processo reacional, neoplásico ou genético. Mutações no gene SH3BP2 foram identificadas em pacientes com querubismo, condição que compartilha várias características clínicas, radiográficas e histopatológicas com a LCCG. Para testar a hipótese de que tais mutações seriam responsáveis por, ou estariam associadas a LCCG e na tentativa de melhor entender a diferenciação microscópica/morfométrica das lesões agressivas e não agressivas, vinte e cinco pacientes portadores de LCCG foram selecionados para o estudo. O DNA foi obtido através do sangue e de espécimes em blocos de parafina, oriundos de biópsias e tratamento cirúrgico. Um estudo microscópico morfométrico foi paralelamente realizado, para avaliar o número de células gigantes e densidade de volume das mesmas nas lesões agressivas e não agressivas. O sequenciamento genético dos treze exons do gene SH3BP2 nos vinte e cinco pacientes estudados evidenciou uma alteração no códon do exon 4 em 10 pacientes. A densidade de volume de células gigantes foi maior nas lesões agressivas quando comparadas às não agressivas (p=0,013). Não houve diferença significante quanto ao número de células gigantes/mm2 em lesões agressivas e não agressivas (p =0,245).

Central giant cell lesion (CGCL) is a benign disease of the jaws, with uncertain behavior, ranging from mild asymptomatic slow-growing swelling to an aggressive form, with pain, radicular and bone resorption and cortical destruction. Its aetiology is still unknown and there is discussion whether it is a reactive, neoplastic or genetic disease. Mutations on gene SH3BP3 were identified in patients with cherubism, which shares several clinical, radiographic and histopathological features with CGCL. In order to test the hypothesis that such mutations would be responsible for or would be related to CGCL and also in order to better understand microscopic morphometric differentiation of the aggressive and non-aggressive lesions, 25 patients with CGCL were selected to this study. DNA was extracted from blood samples and from tissue samples, obtained by biopsy or surgical treatment. Microscopic morphometric assessment was also performed, in order to evaluate the number and the volume density of the giant cells in aggressive and in non-aggressive lesions. Gene sequencing of all 13 exons in gene SH3BP3, performed on each of the 25 patients, showed an alteration in one codon from exon 4, in ten patients. Volume density of giant cells was greater in aggressive lesions than in non-aggressive ones (p=0,013). There was no significant difference on the number of giant cells per mm2 when comparing aggressive and non-aggressive lesions.