Discordant bone marrow involvement in non-Hodgkin lymphoma

Abstract

A discordant lymphoma occurs where 2 distinct histologic subtypes coexist in at least 2 separate anatomic sites. Histologic discordance is most commonly observed between the bone marrow (BM) and lymph nodes (LNs), where typically aggressive lymphoma is found in a LN biopsy with indolent lymphoma in a BM biopsy. Although the diagnosis of discordance relied heavily on histopathology alone in the past, the availability of flow cytometry and molecular studies have aided the identification of this entity. The true prevalence and clinical ramifications of discordance remain controversial as available data are principally retrospective, and there is therefore little consensus to guide optimal management strategies. In this review, we examine the available literature on discordant lymphoma and its outcome, and discuss current therapeutic approaches. Future studies in discordant lymphoma should ideally focus on a large series of patients with adequate tissue samples and incorporate molecular analyses.

The utility of bone marrow sampling in the diagnosis and staging of lymphoma in South Africa

“…The high rates of BMI detected in newly diagnosed lymphomas are of particular importance in HG B NHL and HL. The BMI rates found in HG B NHL are comparable with the variable rates reported, which range from 11% to 34% in DLBCL to 70% in BL . The BMI rate found in HL far exceeds the average developed world rate of 5% .…”

“…The BMI rate and median CD4 count in HIV+ PBL are notewor- range from 11% to 34% in DLBCL 25,26,34 to 70% in BL. 35 The BMI rate found in HL far exceeds the average developed world rate of 5%.…”

“…In addition to detection of lymphomatous involvement, BMB enables evaluation of stromal elements, haematopoietic reserve and iron stores. Low grade (LG) BM discordance in HG B NHL and HG transformation in LG B NHL may also be detected.…”

Tumor Heterogeneity in Lymphomas: A Different Breed

“…phoma at different anatomical sites. This spatial form of intratumoral heterogeneity, known as discordant involvement, occurs in 5-7% of patients according to recent studies [29][30][31] and most often presents as DLBCL in an LN with discordant low-grade lymphoma infiltration in the BM [20]. In patients with a low-grade and a highgrade component at different sites, it is of major importance to investigate the clonal relationship between the 2 components.…”

“…In a proportion of patients, 2 distinct lymphoma entities as defined by the WHO criteria can be diagnosed either at different time points of the disease or simultaneously at the first diagnosis in the same organ or in different organs, such as lymph nodes (LN) and bone marrow (BM). Irrespectively of the setting, it is of major importance to investigate -usually by studying clonal immunoglobulin or T-cell receptor rearrangementswhether intratumoral heterogeneity is the result of evolution of the neoplastic clone or indicates the presence of a second, clonally unrelated neoplasm [20].…”