RESUMO
The formation, development and dissolution of germinal centers is a major part of immune system function. It is important to differentiate neoplastic processes from follicular hyperplasia and regressive follicular changes. Better understanding of germinal center development and dissolution also provides diagnostic clues to the underlying pathologic process. It is also important in identifying the immune basis of different pathologic entities as well as in immunotherapy decision making and follow up. In this study, we characterize the immunoarchitecture of lymphoid follicles with a focus on germinal center in one representative case, each of commonly encountered benign and malignant lymph node disorders, with morphologic and immunohistochemical alterations of germinal centers. The cases include reactive follicular hyperplasia (FH), florid follicular hyperplasia (FFH), follicular lymphoma (FL), angioimmunoblastic T-cell lymphoma (AITL), hyaline-vascular Castleman disease (HVCD), progressive transformation of germinal centers, nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), lymphocyte-rich classic Hodgkin lymphoma (LR-CHL), human immunodeficiency virus (HIV)-associated follicular dissolution and chronic lymphocytic leukemia (CLL) with proliferation centers (PC). A panel of antibodies were used namely CD3, CD20, CD10, BCL2, BCL6, CD21, CD23, CD35, FOXP1, GCET1, HGAL/GCET2, LMO2, MUM1, IgD, Ki67, PD1 and PD-L1. We found that these entities show distinct immunoarchitectural patterns of germinal center formation, development and regression, particularly, the distribution of mantle zone B-cells, follicular helper T cells (Tfh) and FDC meshworks, confirming the influence of antigenic stimulation and status of immune system in these changes. This also confirms the interrelationship of underlying immunologic mechanisms in these disease processes.
Assuntos
Biomarcadores/metabolismo , Centro Germinativo/patologia , Linfoma Folicular/patologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Humanos , Hiperplasia/imunologia , Hiperplasia/metabolismo , Hiperplasia/patologia , Imuno-Histoquímica , Linfoma Folicular/imunologia , Linfoma Folicular/metabolismo , Linfócitos T/metabolismo , Linfócitos T/patologiaRESUMO
The Hodgkin lymphomas are a family of unique lymphoma subtypes, in which the nature of the neoplastic cell was enigmatic for many years. Much of the mystery has been solved, with all forms now considered to be of B-cell origin, in most cases of germinal centre derivation. Today we recognize Hodgkin lymphoma as an eponym that encompasses multiple entities. One of the unifying themes is the major contribution from the tumour microenvironment. Both the character of the neoplastic cells and the nature of the immune environment are critical to accurate diagnosis. Moreover, an understanding of the molecular alterations that characterize both the neoplastic cells and their microenvironment have led to therapeutic advances, targeting both neoplastic and reactive components. Other conditions may foster a similar inflammatory milieu and lead to lymphoproliferations that mimic the Hodgkin lymphomas. In this review we provide an update on the diagnostic features of the various subtypes and include additional information relevant for prognostic evaluation and investigation of potential therapeutic targets. Additionally, we also discuss those conditions that often cause confusion in diagnosis and need to be distinguished from the Hodgkin lymphomas.
Assuntos
Doença de Hodgkin/diagnóstico , Microambiente Tumoral , Diagnóstico Diferencial , Doença de Hodgkin/metabolismo , Doença de Hodgkin/patologia , Doença de Hodgkin/terapia , HumanosAssuntos
Neoplasias do Sistema Nervoso Central/secundário , Leucemia Promielocítica Aguda/patologia , Recidiva Local de Neoplasia/patologia , Adulto , Antineoplásicos/uso terapêutico , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/patologia , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Masculino , Recidiva Local de Neoplasia/tratamento farmacológico , Tretinoína/uso terapêuticoAssuntos
Neoplasias do Endométrio/patologia , Linfoma Difuso de Grandes Células B/patologia , Adulto , Neoplasias do Endométrio/complicações , Neoplasias do Endométrio/metabolismo , Feminino , Humanos , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/metabolismo , PrognósticoAssuntos
Histiocitose/etiologia , Cadeias lambda de Imunoglobulina/análise , Corpos de Inclusão/química , Linfoma de Zona Marginal Tipo Células B/complicações , Paraproteínas/análise , Neoplasias do Timo/complicações , Adulto , Cristalização , Feminino , Histiócitos/química , Histiócitos/ultraestrutura , Histiocitose/metabolismo , HumanosAssuntos
Células Dendríticas/patologia , Doença de Hodgkin/diagnóstico , Células de Langerhans/patologia , Transtornos Linfoproliferativos/diagnóstico , Adulto , Idoso , Diagnóstico Diferencial , Doença de Hodgkin/patologia , Humanos , Hiperplasia/patologia , Transtornos Linfoproliferativos/patologia , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Human herpes virus 6 (HHV-6) is a member of the ß-herpesvirinae subfamily. Most people acquire HHV-6 primary infection early in life and reactivation may occur, most often in immunocompromised individuals, leading to various clinical manifestations. HHV-6 infected cells may be identified in lymph nodes in both reactive and neoplastic conditions. Cases were retrieved from the hematopathology consultation service archives at National Institutes of Health from 2003 to 2017 in which infection by HHV-6 had been documented by immunohistochemical stains to HHV-6 gp60/110 envelope glycoprotein. Five cases of reactive lymphadenitis and 3 cases of lymphoma; 2 angioimmunoblastic T-cell lymphoma and 1 classic Hodgkin lymphoma, positive for HHV-6 were identified. The reactive lymph nodes showed marked paracortical hyperplasia and admixed large atypical lymphoid cells exhibiting pleomorphic nuclei, vesicular chromatin, and prominent eosinophilic intranuclear inclusions. Vascular proliferation and necrosis were also present, raising suspicion of peripheral T-cell lymphoma. The 3 cases of lymphoma showed similar viral inclusions, in addition to the characteristic features diagnostic of the lymphoma. Staining for HHV-6 was positive with a membranous and Golgi pattern and was restricted to cells with evident inclusions on hematoxylin and eosin. HHV-6 infected cells were positive for CD3 and CD4. HHV-6 lymphadenitis can present with morphologic atypia creating a diagnostic pitfall for lymphoma. In such cases, careful attention to the characteristic viral inclusions can lead to immunohistochemical analysis highlighting the replicating virus. In cases of lymphoma, identification of the inclusions is key in detecting the associated infection as well as in avoiding misinterpretation of the lymphoma subtype.
Assuntos
Infecções por Herpesviridae/virologia , Herpesvirus Humano 6/isolamento & purificação , Leucemia-Linfoma de Células T do Adulto/virologia , Linfonodos/virologia , Linfadenite/virologia , Linfoma de Células B/virologia , Linfoma de Células T/virologia , Adolescente , Adulto , Biópsia , Complexo CD3/análise , Antígenos CD4/análise , Diagnóstico Diferencial , Feminino , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/patologia , Herpesvirus Humano 6/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Imuno-Histoquímica , Corpos de Inclusão Viral/patologia , Leucemia-Linfoma de Células T do Adulto/imunologia , Leucemia-Linfoma de Células T do Adulto/patologia , Linfonodos/imunologia , Linfonodos/patologia , Linfadenite/imunologia , Linfadenite/patologia , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Linfoma de Células T/imunologia , Linfoma de Células T/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Proteínas Virais/análiseRESUMO
To date, sarcocystis has been considered an asymptomatic infection in humans. Even though cases with glomerulonephritis have been reported in animals with sarcocystis, there have been no reports of a similar occurrence in humans. We report a case of acute proliferative glomerulonephritis and leukocytoclastic vasculitis in a patient with sarcocystis infestation.