ABSTRACT
Abstract Background: Diffuse large B-cell lymphoma (DLBCL) makes up from 25% to 40% of all non-Hodgkin lymphomas (NHL) and is the most common histological subtype worldwide. In Ecuador, DLBCL makes up 49% of all NHL cases, but there have been no studies on the immunophenotypic classificationof DLBCL in germinal center (GC) and non-germinal center (NGC)subtypes.This study was conducted to ascertain the immunophenotypic profile of DLBCL in an Ecuadorian hospital. Methods: A total of 38 DLBCL cases from 2006 to 2015 were compiled from the Pathology Service at Metropolitan Hospital (HM) in Quito, Ecuador. Eleven of these cases failed to meet the inclusion criteria; thus, the final sample consisted of 27 cases. Manual tissue microarrays were constructed, and three immunohistochemical markers (CD10, BCL6, and MUM1) were applied according to the Hans algorithm; in addition, the expression of the c-myc protein expression was also investigated. Results: The results showed that 77.8% of cases were of the GC subtype, 11.1% were NGC, and 11.1% were unclassifiable according to the Hans algorithm. Conclusions: The most frequent DLBCL subtype was GC, with 21 cases; and 40.7% of these cases overexpressed c-myc.
Resumen Antecedentes: El linfoma difuso de células grandes B (LDCGB) constituye el 25 al 40% del total de los linfomas no Hodgkin (LNH) y es el subtipo histológico más frecuente en el mundo. En Ecuador el LDCGB corresponde al 49% del total de los casos de LNH, sin embargo no hay estudios de clasificación inmunofenotípica del LDCGB en centro germinal (CG) y no centro germinal (NCG). Este estudio se realizó para conocer el perfil inmunofenotípico del LDCGB en un hospital de Ecuador. Métodos: Se recopiló del Servicio de Patología del Hospital Metropolitano de Quito, Ecuador, un total de 38 casos de LDCGB desde el 2006 al 2015, de los cuales 11 no cumplieron con los criterios de inclusión. La muestra final fue de 27 casos. Se realizaron microarreglos tisulares manuales para la aplicación de tres marcadores de inmunohistoquímica según el algoritmo de Hans (CD10, BCL6 y MUM1) y luego se correlacionó con la sobreexpresión de la proteína c-MYC. Resultados: El 77,8% de casos fue tipo CG, 11,1% fue NCG y 11,1% fueron inclasificables según Hans. Conclusiones: El subtipo de LDCGB más frecuente fue CG con 21 casos y de estos 40,7% sobreexpresaron c-MYC.
Subject(s)
Humans , Lymphoma, B-Cell , Ecuador , Protein C , HospitalsABSTRACT
CONTEXT AND OBJECTIVE: Genetic abnormalities in cell proliferation-regulating genes have been described in premalignant lesions. The aims here were to evaluate c-myc protein expression in non-palpable breast lesions associated with microcalcifications, detected by screening mammography, and to compare these results with histopathological, clinical and epidemiological variables. DESIGN AND SETTING: Analytical cross-sectional study, with retrospective data collection, in a university hospital in São Paulo. METHODS: Seventy-nine female patients who underwent routine mammography between 1998 and 2004 were studied. Lesions classified by the Breast Imaging Reporting and Data System (BI-RADS) as 4 or 5 underwent percutaneous biopsy using a large-core needle. Ninety-eight lesions were studied anatomopathologically. Paraffin blocks properly representing the lesions were selected for immunohistochemical analyses using the streptavidin-biotin-peroxidase technique with monoclonal mouse c-myc antibodies. RESULTS: Among the 98 lesions, 29 (29.6 percent) contained malignant neoplasia; 40 (40.8 percent) had a positive immunohistochemical reaction for c-myc. When the groups were divided between lesions without atypias versus atypical lesions plus malignant lesions, 31.03 percent of the 58 lesions without atypias were positive for c-myc and 55 percent of the 40 malignant and atypical lesions (P = 0.018). Comparing the atypical lesions with ductal carcinoma in situ versus the benign lesions without atypias, c-myc was present in 51.61 percent of the 31 atypical lesions and 31.03 percent of the benign lesions without atypias (P = 0.057). CONCLUSION: C-myc protein was more frequently expressed in atypical and malignant lesions than in benign lesions without atypias. C-myc expression correlated with the presence of atypias (P = 0.018).
CONTEXTO E OBJETIVO: Alterações nos genes reguladores da proliferação celular foram descritas em lesões pré-malignas. Os objetivos foram avaliar a expressão da proteína c-myc em biópsias de lesões mamárias não-palpáveis associadas a microcalcificações detectadas em mamografias de rastreamento e comparar estes resultados com as variáveis histopatológicas, clínicas e epidemiológicas. DESENHO E LOCAL: Estudo retrospectivo, em um hospital universitário em São Paulo. MÉTODOS: Setenta e nove pacientes do sexo feminino submetidas a mamografia de rotina de 1998 a 2004 foram estudadas. As lesões classificadas pelo sistema BI-RADS (Breast Imaging Reporting and Data) como 4 e 5 sofreram biópsias percutâneas com agulha grossa. Do ponto de vista anatomopatológico, foram estudadas 98 lesões. Os blocos com representação adequada para estudo imunoistoquímico com a técnica da estreptoavidina-biotina-peroxidase com o anticorpo monoclonal de camundongo c-myc foram incluídos. RESULTADOS: Das 98 lesões, 29 (29,6 por cento), continham neoplasia maligna; 40 (40,8 por cento) tiveram reação de imunoistoquímica positiva para o c-myc. Quando divididos os grupos em lesões sem atipia versus lesões atípicas mais lesões malignas, encontramos o c-myc positivo em 31,03 por cento das 58 lesões sem atipias e 55 por cento das 40 lesões atípicas e malignas (P = 0,018). Quando agrupamos as lesões atípicas com o carcinoma ductal in situ (CDIS) versus as lesões benignas sem atipias, observamos a presença do c-myc em 51,61 por cento das 31 lesões atípicas e 31,03 por cento das lesões benignas sem atipias (P = 0,057). CONCLUSÃO: A proteína c-myc está mais frequentemente expressa em lesões atípicas e malignas do que em lesões benignas sem atipia. A expressão do c-myc está correlacionada com a presença de atipia (P = 0,018).