Gray zones around diffuse large B cell lymphoma. Conclusions based on the workshop of the XIV meeting of the European Association for Hematopathology and the Society of Hematopathology in Bordeaux, France

Abstract

The term “gray-zone” lymphoma has been used to denote a group of lymphomas with overlapping histological, biological, and clinical features between various types of lymphomas. It has been used in the context of Hodgkin lymphomas (HL) and non-Hodgkin lymphomas (NHL), including classical HL (CHL), and primary mediastinal large B cell lymphoma, cases with overlapping features between nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B cell lymphoma, CHL, and Epstein–Barr-virus-positive lymphoproliferative disorders, and peripheral T cell lymphomas simulating CHL. A second group of gray-zone lymphomas includes B cell NHL with intermediate features between diffuse large B cell lymphoma and classical Burkitt lymphoma. In order to review controversial issues in gray-zone lymphomas, a joint Workshop of the European Association for Hematopathology and the Society for Hematopathology was held in Bordeaux, France, in September 2008. The panel members reviewed and discussed 145 submitted cases and reached consensus diagnoses. This Workshop summary is focused on the most controversial aspects of gray-zone lymphomas and describes the panel’s proposals regarding diagnostic criteria, terminology, and new prognostic and diagnostic parameters.

Clinical, pathological and genetic features of primary mediastinal large B-cell lymphomas and mediastinal gray zone lymphomas in children

“…According to previous detailed descriptions, 13,18 several conditions may lead to the diagnosis of MGZL. In the first case the lymphoma may show variable morphology resembling cHL in one area and PMBCL in another area (synchronous or composite lymphoma).…”

The spectrum of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma: a description of 10 cases

“…The separation between these two entities is not always clearcut, but extremely important for therapeutic decision making. 7 The overlap between primary mediastinal B-cell lymphoma and mainly the nodular sclerosis subtype of classical Hodgkin lymphoma includes clinical, pathological, genetic and molecular features. Both classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma share several clinicopathological characteristics such as female predominance, presence in young adulthood as well as frequent manifestation as an anterior mediastinal mass.…”

“…[1][2][3] The two recognized members of 'gray zone lymphoma' include those that show features intermediate between primary mediastinal large B-cell lymphoma and classical Hodgkin lymphoma, and diffuse large B-cell lymphoma and Burkitt lymphoma. [3][4][5][6][7] The overlap between primary mediastinal large B-cell lymphoma and classical Hodgkin lymphoma has been recognized for some time under the terms 'mediastinal gray zone lymphoma', 3,5 or 'large B-cell lymphoma with Hodgkin-like features'. 8 More recently, gene expression profiling studies have demonstrated that the overlap in the expression of genes shared between primary mediastinal large B-cell lymphoma and classical Hodgkin lymphoma is significantly higher than that between primary mediastinal large B-cell lymphoma and diffuse large B-cell lymphoma.…”

“…Most published reports predate the WHO 2008 classification. 7 The European Association for Hematopathology (EAHP) 2008 workshop report provides a series of cases classified according to the WHO 2008 classification; however, it does not provide sufficient clinical information, including clinical outcome data. 7 Two recent studies have reported clinical outcome information in cases occurring in the pediatric age group.…”

“…7 The European Association for Hematopathology (EAHP) 2008 workshop report provides a series of cases classified according to the WHO 2008 classification; however, it does not provide sufficient clinical information, including clinical outcome data. 7 Two recent studies have reported clinical outcome information in cases occurring in the pediatric age group. 16,17 Given the rarity of such cases and the difficulty they impose on diagnosis and classification as well as management of patients, additional studies are needed to fully understand the spectrum represented by this new WHO category of lymphomas.…”