Diffuse large B-cell lymphoma with concordant bone marrow involvement has peculiar genomic profile and poor clinical outcome

A comprehensive review of the role of bone marrow biopsy and PET-CT in the evaluation of bone marrow involvement in adults newly diagnosed with DLBCL

Diffuse large B cell lymphoma (DLBCL) is one of the most prevalent subtypes of non-Hodgkin lymphoma (NHL) and is known for commonly infiltrating extra-nodal sites. The involvement of the bone marrow by lymphoma cells significantly impacts the staging, treatment, and prognosis among the extra-nodal sites in DLBCL. Bone marrow biopsy has been considered the standard diagnostic procedure for detecting bone marrow involvement. However, advancements in imaging techniques, such as positron emission tomography-computed tomography (PET-CT), have shown an improved ability to detect bone marrow involvement, making the need for bone marrow biopsy debatable. This review aims to emphasize the importance of bone marrow evaluation in adult patients newly diagnosed with DLBCL and suggest an optimal diagnostic approach to identify bone marrow involvement in these patients.

The genetic polymorphisms of immune-related genes contribute to the susceptibility and survival of lymphoma

BACKGROUND

Though immunological abnormalities have been proven involved in the pathogenesis of lymphoma, the underlying mechanism remains unclear.

METHODS

We investigated 25 single nucleotide polymorphisms (SNPs) of 21 immune-related genes and explored their roles in lymphoma. The genotyping assay of the selected SNPs was used by the Massarray platform. Logistic regression and Cox proportional hazards models were used to analyze the associations of SNPs and the susceptibility of lymphoma or clinical characteristics of lymphoma patients. In addition, Least Absolute Shrinkage and Selection Operator regression was used to further analyze the relationships with the survival of lymphoma patients and candidate SNPs, and the significant difference between genotypes was verified by the expression of RNA.

RESULTS

By comparing 245 lymphoma patients with 213 healthy controls, we found eight important SNPs related to the susceptibility of lymphoma, which were involved in JAK-STAT, NF-κB and other functional pathways. We further analyzed the relationships between SNPs and clinical characteristics. Our results showed that both IL6R (rs2228145) and STAT5B (rs6503691) significantly contributed to the Ann Arbor stages of lymphoma. And the STAT3 (rs744166), IL2 (rs2069762), IL10 (rs1800871), and PARP1 (rs907187) manifested a significant relationship with the peripheral blood counts in lymphoma patients. More importantly, the IFNG (rs2069718) and IL12A (rs6887695) were associated with the overall survival (OS) of lymphoma patients remarkably, and the adverse effects of GC genotypes could not be offset by Bonferroni correction for multiple comparison in rs6887695 especially. Moreover, we determined that the mRNA expression levels of IFNG and IL12A were significantly decreased in patients with shorter-OS genotypes.

CONCLUSIONS

We used multiple methods of analysis to predict the correlations between lymphoma susceptibility, clinical characteristics or OS with SNPs. Our findings reveal that immune-related genetic polymorphisms contribute to the prognosis and treatment of lymphoma, which may serve as promising predictive targets.

Hemophagocytic lymphohistiocytosis as an onset of diffuse large B‑cell lymphoma: A case report

A 53-year-old male presented with a 1-month history of hyperpyrexia. The clinical manifestations revealed hemophagocytic lymphohistiocytosis (HLH). Although a lymph node biopsy could not be obtained, a bone marrow biopsy revealed the activated B-cell subtype of diffuse large B-cell lymphoma (DLBCL). After being treated with HLH-1994 (dexamethasone and etoposide), a rituximab-containing chemotherapy and target agents involving bortezomib, the patient achieved remission. To understand the molecular profile of patient, next-generation sequencing and MYD88 L265P mutation examinations were performed, and the patient was determined to be positive for the MYD88 L265P mutation. Reports of DLBCL with plasmacytic differentiation and a MYD88 innate immune signal transduction adaptor L265P mutation concurrent with HLH are rare. Early recognition, precise diagnosis and timely therapy are pivotal in improving patient prognosis. Furthermore, molecular profiling enables researchers to develop potential therapies aimed at the activated NF-κB and endoplasmic reticulum stress signaling pathways. The present study highlights this pathogenesis and provides suggestions for further individualized therapeutics.

The value of bone marrow biopsy for staging of patients with primary CNS lymphoma

BACKGROUND

In patients with presumed primary CNS lymphoma (PCNSL) a systemic manifestation is found only in a small minority. Although bone marrow biopsy (BMB) is recommended for staging, its diagnostic value is unclear.

METHODS

A retrospective analysis of 392 patients with presumed PCNSL from three university hospitals and 33 patients with secondary CNS lymphoma (SCNSL) and initial CNS involvement from a multicentre Germany-wide prospective registry was performed.

RESULTS

A BMB was performed and documented in 320/392 patients with presumed PCNSL; 23 had pathologic results. One harboured the same lymphoma in the brain and bone marrow (BM), 22 showed findings in BM discordant to the histology of brain lymphoma; n=12 harboured a low grade lymphoma in the bone marrow, the other showed B-cell proliferation but no proof of lymphoma (n=5), monoclonal B-cells (n=3) or abnormalities not B-cell associated (n=2). In the group of SCNSL with initial CNS manifestation 32/33 patients underwent BMB; seven were documented with bone marrow involvement (BMI); one had concordant results in the brain and bone marrow with no other systemic manifestation. Six had additional systemic lymphoma manifestations apart from the brain and bone marrow.

CONCLUSIONS

In only two out of 352 (0.6%) patients with CNS lymphoma (320 presumed PCNSL and 32 SCNSL) BMB had an impact on diagnosis and treatment. While collected in a selected cohort these findings challenge the value of BMB as part of routine staging in presumed PCNSL.

Large B-cell lymphoma presenting primarily in bone marrow is frequently associated with haemophagocytic lymphohistiocytosis and has distinct cytogenetic features

The criteria for primary bone marrow large B-cell lymphoma (PBMLBCL) have not yet been clearly established. We aimed to investigate the clinicopathological features of PBMLBCLs (27 cases) and large B-cell lymphomas (LBCLs) with secondary marrow involvement (55 cases). PBMLBCL was defined as LBCLs presenting initially in bone marrow without lymphadenopathy, extramedullary tumour or localised bone tumour, and no evidence of transformation from low grade B-cell lymphoma. Compared with the patients in the secondary group, more patients in the primary group had haemophagocytic lymphohistiocytosis, cytogenetic aberrations, cytopenias, and atypical lymphocytes in peripheral blood. The most common chromosome abnormality in both groups was 6q deletion. The primary group had additional chromosome 10, 2, and 3 abnormalities. The acquired chromosome 10 aberration was associated with the risk of haemophagocytic lymphohistiocytosis. The 1-year survival rate was lower in the primary group than in the secondary group; however, the difference was not significant when the cases without chemotherapy plus rituximab were excluded. Moreover, multivariate analysis revealed that relatively high white blood cell count, not receiving chemotherapy plus rituximab, and cytogenetic aberrations were poor prognostic factors in the secondary group, but only not receiving chemotherapy plus rituximab was retained in the primary group. In conclusion, PBMLBCL is genetically and clinically distinct. Although patients with PBMLBCL generally have a poor outcome, the disease is treatable and some patients become long-term survivors.

Biological Features and Prognostic Impact of Bone Marrow Infiltration in Patients with Diffuse Large B-Cell Lymphoma

The biology and clinical impact of bone marrow (BM) infiltration in patients with diffuse large B-cell lymphoma (DLBCL) remains unclear in the rituximab era. We retrospectively analyzed 232 patients diagnosed with DLBCL at our center between 1999 and 2014. Concordant-presence of large cells similar to those of the lymph node biopsy- and discordant-infiltration by small cells forming lymphoid aggregates, lacking cytological atypia-BM infiltration was defined by histological criteria and further characterized by flow cytometry (FCM). Cell of origin (COO) was determined using Hans’ algorithm. For the clonal relationship between tumor and discordant BM, the VDJH rearrangement was analyzed. Survival analyses were restricted to 189 patients treated with rituximab and chemotherapy. Thirty-six (16%) had concordant, and 37 (16%) discordant BM infiltration. FCM described different indolent lymphomas among discordant cases, clonally related with DLBCL in 10/13 available samples. Median follow-up was 58 months. 5-year-progression-free survival (PFS) for non-infiltrated, discordant and concordant groups was 68%, 65% and 30%, respectively (p < 0.001). Combining COO and BM infiltration, patients with discordant BM and non-germinal center B-cell COO also had decreased 5-year-PFS (41.9%). In multivariate analysis, concordant BM had an independent effect on PFS (HR 2.5, p = 0.01). Five-year cumulative incidence of central nervous system (CNS) relapse was 21%, 4% and 1% in concordant, discordant and non-infiltrated groups, respectively (p < 0.001). In conclusion, concordant BM infiltration represents a subset with poor prognosis, whereas the prognostic impact of discordant BM infiltration could be limited to non-CGB cases.

Trends in Bone Marrow Sampling and Core Biopsy Specimen Adequacy in the United States and Canada: A Multicenter Study

OBJECTIVES

To assess bone marrow (BM) sampling in academic medical centers.

METHODS

Data from 6,374 BM samples obtained in 32 centers in 2001 and 2011, including core length (CL), were analyzed.

RESULTS

BM included a biopsy (BMB; 93%) specimen, aspirate (BMA; 92%) specimen, or both (83%). The median (SD) CL was 12 (8.5) mm, and evaluable marrow was 9 (7.6) mm. Tissue contraction due to processing was 15%. BMB specimens were longer in adults younger than 60 years, men, and bilateral, staging, and baseline samples. Only 4% of BMB and 2% of BMB/BMA samples were deemed inadequate for diagnosis. BM for plasma cell dyscrasias, nonphysician operators, and ancillary studies usage increased, while bilateral sampling decreased over the decade. BM-related quality assurance programs are infrequent.

CONCLUSIONS

CL is shorter than recommended and varies with patient age and sex, clinical circumstances, and center experience. While pathologists render diagnoses on most cases irrespective of CL, BMB yield improvement is desirable.

Clinical impact of CD5 expression in Korean patients with diffuse large B-cell lymphoma

BACKGROUND

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) accounts for 5-10% of DLBCL cases and has poor patient outcomes. However, most studies on CD5+ DLBCL were performed in Japanese patients and only few data are available for Korean population. In this study, we investigated the clinical characteristics and prognostic impact of CD5 expression in Korean patients with bone marrow (BM) involvement of DLBCL.

METHODS

Patients who were initially diagnosed with BM involvement of de novo DLBCL from 2005 to 2013 were included. Clinicopathological features and outcomes of patients were compared between CD5+ and CD5 negative (CD5-) DLBCL.

RESULTS

Among a total of 57 patients, the number of patients with CD5+ and CD5- DLBCL were 13 and 44, respectively. Clinical and laboratory features of CD5+ DLBCL were not significantly different from those of CD5- DLBCL. The 3-year overall survival (OS) rates for CD5+ and CD5- DLBCL were 20.2% and 59.0%, respectively (P=0.031), and 3-year progression-free survival (PFS) rates for CD5+ and CD5- DLBCL were 23.1% and 50.1%, respectively (P=0.055).

CONCLUSION

CD5+ DLBCL with BM involvement showed an inferior survival tendency compared to CD5- DLBCL, and thorough evaluation of CD5 expression might be helpful to predict the prognosis of patients with DLBCL.

Concordant bone marrow involvement of diffuse large B-cell lymphoma represents a distinct clinical and biological entity in the era of immunotherapy

In diffuse large B-cell lymphoma (DLBCL), the clinical and biological significance of concordant and discordant bone marrow (BM) involvement have not been well investigated. We evaluated 712 de novo DLBCL patients with front-line rituximab-containing treatment, including 263 patients with positive and 449 with negative BM status. Compared with negative BM disease, concordant BM adversely impacted overall and progression-free survival, independent of the International Prognostic Index (IPI) and cell-of-origin classification. Once BM is concordantly involved, poor prognosis was not associated with the extent of BM involvement. Conversely, patients with discordant BM showed favorable overall survival similar to stage I-II DLBCL. A BM-adjusted IPI, using three parameters: concordant BM involvement, age >60 years, and performance status >1, improves the risk stratification for DLBCL with positive BM. Intensive immunochemotherapy seemingly rendered survival benefit for patients with concordant BM, as did rituximab maintenance for the discordant BM group. Frequently revealing adverse clinical and molecular characteristics, patients with concordant BM demonstrated gene expression signatures relevant to tumor cell proliferation, migration and immune escape. In conclusion, clinical and biological heterogeneity is seen in DLBCL with positive BM but concordant BM involvement represents a distinct subset with unfavorable gene signatures, high-risk clinicopathologic features and poor prognosis.

Utility of Bone Marrow Biopsy and Aspirate for Staging of Diffuse Large B Cell Lymphoma in the Era of Positron Emission Tomography With 2-Deoxy-2-[Fluorine-18]fluoro-deoxyglucose Integrated With Computed Tomography

BACKGROUND

About one-third of patients with diffuse large B cell lymphoma (DLBCL) have lymphomatous bone marrow involvement (BMI) at the time of diagnosis, and bone marrow aspirate/biopsy (BMAB) is considered the gold standard to detect such involvement. [¹⁸F] fluorodeoxyglucose positron emission tomography combined with computed tomography (PET-CT), has become standard pretreatment imaging in DLBCL and may be a noninvasive alternative to BMAB to ascertain BMI. Prior studies have suggested that PET-CT scan may obviate the need for BMAB as a component for staging patients with newly diagnosed DLBCL, but this is not yet a standard of practice. The aim of this retrospective study was to determine the accuracy of PET-CT in detecting BMI in DLBCL and to define 2-year and 5-year overall survival based on BMI by BMAB versus PET-CT.

METHODS

We reviewed institutional records of all patients with newly diagnosed DLBCL between January 2004 and December 2013 who underwent pretreatment PET-CT and BMAB. PET-CT images were visually assessed for BMI, including the posterior iliac crest. Patients with primary mediastinal DLBCL, previous history or coexistence of another lymphoma subtype, and those with a nondiagnostic BMAB, and in whom the PET-CT did not show marrow signal abnormality, were excluded from the analysis. Ann Arbor stage was determined using PET-CT with and without the contribution of BMAB, and the proportion of stage IV cases by each method was measured.

RESULTS

Among 99 eligible patients, the median age was 62 years (range, 24-88 years), 62 (63%) were male, 53 (53%) had elevated serum lactate dehydrogenase, and 17 (16%) had an Eastern Community Oncology Group performance status of > 2. Thirteen (12%) patients had more than 1 extra-nodal site of lymphoma involvement. Revised International Prognostic Index score was 1 in 39 (37%) patients, 2 in 42 (40%) patients, 3 in 20 (19%) patients, and 4 in 4 (4%) patients. A total of 38 (36%) patients had BMI established by either PET-CT (n = 24; 24%), BMAB (n = 14; 14%), or by both modalities (n = 12; 12%). Twelve (50%) of the 24 patients with positive PET-CT had BMI by DLBCL, whereas only 2 (3%) of the 75 patients with negative PET-CT showed BMI. BMAB upstaged 1 (2%) of the 53 stage I/II patients to stage IV. The sensitivity and specificity of PET-CT scan to detect BMI by DLBCL was 86% (95% confidence interval, 51.9%-95.7%) and 87% (95% confidence interval, 76%-92%), respectively. Eighty-five (86%) patients had concordant results between lymphomatous BMAB and PET-CT (12 patients were positive for both; 73 patients were negative for both), and 14 (14%) patients had a discordant interpretation (2 patients were positive by BMAB and negative by PET-CT, and 12 patients were negative by BMAB and positive by PET-CT). The positive predictive value of PET-CT was only 50%, whereas the negative predictive value was 98%. The accuracy of PET-CT was 86%. Although patients with positive BMAB had inferior 5-year overall survival estimates compared with those with negative BMAB (66% vs. 85%; P = .08), no such difference was demonstrated between PET-CT-positive and PET-CT-negative patients (79% vs. 83%; P = .30).

CONCLUSIONS

In patients with newly diagnosed DLBCL, PET-CT is accurate in detecting BMI by DLBCL. Although PET-CT has a very high negative predictive value for BMI, it overestimates the number of cases with marrow involvement by DLBCL. In clinical practice, routine BMAB may no longer be necessary for all patients with DLBCL who are staged by PET-CT, unless the results would change both staging and therapy. The prognostic implication of BMI identified by PET-CT compared with BMAB remains unknown. Whether a PET-CT precludes the need for a BMAB in patients with DLBCL remains to be evaluated in a prospective study.

Discordant bone marrow involvement in non-Hodgkin lymphoma

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.

Genetic lesions in diffuse large B-cell lymphomas

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in adults, accounting for 35%-40% of all cases. The combination of the anti-CD20 monoclonal antibody rituximab with anthracycline-based combination chemotherapy (R-CHOP, rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone) lead to complete remission in most and can cure more than half of patients with DLBCL. The diversity in clinical presentation, as well as the pathologic and biologic heterogeneity, suggests that DLBCL comprises several disease entities that might ultimately benefit from different therapeutic approaches. In this review, we summarize the current literature focusing on the genetic lesions identified in DLBCL.

Prognostic impact of concordant and discordant bone marrow involvement and cell-of-origin in Korean patients with diffuse large B-cell lymphoma treated with R-CHOP

AIMS

Previous studies have suggested many prognostic factors in diffuse large B-cell lymphoma (DLBCL), but the prognostic importance of cell-of-origin and discordant bone marrow involvement remains unclear. The aim of this study was to evaluate the prognostic impact of bone marrow involvement histological subtype, cell-of-origin subtype and international prognostic index (IPI) scores in patients with DLBCL.

METHODS

Patients who were newly diagnosed with DLBCL and treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) were analysed. Clinical information was reviewed retrospectively. Patients were classified into negative, concordant and discordant bone marrow involvement by histological review. The cell-of-origin types were defined using immunohistochemical analysis.

RESULTS

Both concordant and discordant bone marrow involvement had a negative prognostic impact on progression-free survival, independent of the standard and National Comprehensive Cancer Network (NCCN) IPI scores and cell-of-origin. Patients with non-germinal centre B-cell type showed significantly shorter progression-free survival than those with germinal centre B-cell type. However, non-germinal centre B-cell type did not have a prognostic impact on progression-free survival or overall survival after controlling for the standard and NCCN-IPI and bone marrow involvement.

CONCLUSIONS

Both concordant and discordant bone marrow involvement had an adverse prognostic impact on progression-free survival and overall survival; this was independent of the standard and NCCN-IPI and cell-of-origin (non-germinal centre B-cell type). The NCCN-IPI had more powerful prognostic value than the standard IPI (sIPI). The non-germinal centre B-cell type lost significant prognostic impact on progression-free survival after adjustment for standard and NCCN-IPI and bone marrow involvement.

The significance of pretreatment anemia in the era of R-IPI and NCCN-IPI prognostic risk assessment tools: a dual-center study in diffuse large B-cell lymphoma patients

BACKGROUND

Anemia is frequently identified at the time of diagnosis in patients with diffuse large B-cell lymphoma (DLBCL); however, studies addressing the prognostic significance of this important clinical parameter are lacking.

METHODS

In this dual-center study of patients with DLBCL (n = 556) treated with rituximab-containing regimens, we evaluated the prognostic relevance of anemia at diagnosis in a training set (n = 211) and validated our findings in a second independent patient cohort (n = 345). Using Kaplan-Meier curves as well as univariate and multivariate Cox regression models, we analyzed the impact of anemia on 5-year overall survival (OS) and 5-year disease-free survival (DFS) alongside established prognostic indicators including age, tumor stage, the revised International Prognostic Index (R-IPI), and the recently published NCCN-IPI. The influence of anemia on the predictive accuracy of IPI, R-IPI, and NCCN-IPI prognosis scores was subsequently determined using the Harrell's concordance index.

RESULTS

Anemia was an independent predictor of impaired OS and DFS at 5 years in both DLBCL patient cohorts (P < 0.001, log-rank test). In multivariate analysis, hemoglobin level was also a strong and independent prognostic indicator in patients stratified according to R-IPI or NCCN-IPI score. In survival analysis, the estimated concordance index, using IPI, R-IPI, and NCCN-IPI stratification measures (0.69, 0.64, and 0.70, respectively), improved to 0.70, 0.68, and 0.73, respectively, when anemia was also considered.

CONCLUSION

In this study, we have demonstrated that anemia at the time of diagnosis is an independent predictor of impaired clinical outcome in DLBCL. Furthermore, consideration of hemoglobin levels may improve the accuracy of recently established prognostic tools in lymphoma. Our data encourage further evaluation of the prognostic utility of this readily accessible biological parameter in prospective clinical trials.

Clinical significance of cytogenetic aberrations in bone marrow of patients with diffuse large B-cell lymphoma: prognostic significance and relevance to histologic involvement

Background

Although knowledge of the genetics of diffuse large B-cell lymphoma (DLBCL) has been increasing, little is known about the characteristics and prognostic significance of cytogenetic abnormalities and the clinical utility of cytogenetic studies performed on bone marrow (BM) specimens. To investigate the significance of isolated cytogenetic aberrations in the absence of histologic BM involvement, we assessed the implication of cytogenetic staging and prognostic stratification by a retrospective multicenter analysis of newly diagnosed DLBCL patients.

Methods

We analyzed cytogenetic and clinical data from 1585 DLBCL patients whose BM aspirates had been subjected to conventional karyotyping for staging. If available, interphase fluorescence in situ hybridization (FISH) data were also collected from patients.

Results

Histologic BM involvement were found in 259/1585 (16.3%) patients and chromosomal abnormalities were detected in 192 (12.1%) patients (54 patients with single abnormalities and 138 patients with 2 or more abnormalities). Isolated cytogenetic aberrations (2 or more abnormalities) without histologic involvement were found in 21 patients (1.3%). Two or more cytogenetic abnormalities were associated with inferior overall survival (OS) compared with a normal karyotype or single abnormality in both patients with histologic BM involvement (5-year OS, 16.5% vs. 52.7%; P < 0.001) and those without BM involvement (31.8% vs. 66.5%; P < 0.001). This result demonstrated that BM cytogenetic results have a significant prognostic impact that is independent of BM histology. The following abnormalities were most frequently observed: rearrangements involving 14q32, 19q13, 19p13, 1p, 3q27, and 8q24; del(6q); dup(1q); and trisomy 18. In univariate analysis, several specific abnormalities including abnormalities at 16q22-q24, 6p21-p25, 12q22-q24, and -17 were associated with poor prognosis. Multivariate analyses performed for patients who had either chromosomal abnormalities or histologic BM involvement, revealed IPI high risk, ≥ 2 cytogenetic abnormalities, and several specific chromosomal abnormalities, including abnormalities at 19p13, 12q22-q24, 8q24, and 19q13 were significantly associated with a worse prognosis.

Conclusions

We suggest that isolated cytogenetic aberrations can be regarded as BM involvement and cytogenetic evaluation of BM improves staging accuracy along with prognostic information for DLBCL patients.

Diffuse large B-cell lymphoma and mantle cell lymphoma of the ocular adnexal region, and lymphoma of the lacrimal gland: an investigation of clinical and histopathological features

Diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) constitute two distinct subtypes of non-Hodgkin lymphoma (NHL) associated with considerable morbidity and mortality. Marked diversities with regard to molecular biology and clinical features are recognized in different subsets of the two lymphomas. Because these differences could be related to the location of the lymphoma, it is of interest to investigate the clinical and histopathological features of DLBCL and MCL involving the ocular adnexal region (i.e. the orbit, eyelids, conjunctiva, lacrimal gland and lacrimal sac). Similarly, the lacrimal gland is the only glandular structure within the orbit. Because the lacrimal gland represents an important part of the immunological system, it is of interest to investigate lymphomas involving this location with regard to clinical and histological characteristics.

PURPOSE

  To characterize the clinical and histopathological features of Danish patients with DLBCL of the ocular adnexal region between 1980 and 2009 and of Danish ocular adnexal MCL patients from 1980 to 2005. Furthermore, the aim of this PhD was to review all specimens from patients with lymphoma of the lacrimal gland in Denmark between 1975 and 2009 to determine the distribution of lymphoma subtypes of the lacrimal gland and to describe the clinicopathological features of these patients.

RESULTS

  A total of 34 patients with DLBCL and 21 with MCL of the ocular adnexal region were identified. Twenty-seven patients had lacrimal gland lymphoma, including four DLBCLs and three MCLs from studies I and II. Elderly patients predominated in all three groups, with median ages of 78, 75 and 69 years in the DLBCL, the MCL and the lacrimal gland lymphoma groups, respectively. MCL patients had a preponderance of males, whereas females prevailed among lacrimal gland lymphoma patients. The orbit was the most common site of involvement in DLBCL and MCL. Most DLBCL patients had unilateral involvement, while MCL patients had a high frequency of bilateral involvement. Similarly, localized lymphoma was relatively frequently seen in DLBCL patients in contrast to the predominance of disseminated lymphoma in the MCL group. The majority of lacrimal gland lymphomas were low grade, and the distribution of subtypes was as follows: extranodal marginal zone lymphoma, 10 (37%); follicular lymphoma, 5 (19%); DLBCL, 4 (15%); MCL, 3 (11%); chronic lymphocytic leukaemia/small lymphatic lymphoma, 2 (7%); and unclassified B-cell lymphoma, 3 (11%). The overall survival rates at 3 and 5 years for the entire study group of DLBCL were 42% and 20%, whereas 58% and 22% of MCL patients were alive 3 and 5 years after the time of diagnosis. The 5-year overall survival rate of lacrimal gland lymphoma patients was 70%. Concordant bone marrow involvement and the International Prognostic Index score were predictive factors for the overall survival in the DLBCL group in Cox regression analysis. Rituximab-containing chemotherapy was associated with an improved survival rate in MCL patients.

CONCLUSIONS

  Diffuse large B-cell lymphoma and MCL involving the ocular adnexal region and lymphoma of the lacrimal gland are prevalent among elderly patients. The overall prognosis in DLBCL and MCL was poor, whereas the prognosis for lacrimal gland lymphoma patients was relatively good. Concordant bone marrow involvement and the International Prognostic Index score were independent predictive factors for mortality in the DLBCL group. Chemotherapy containing rituximab significantly improved survival in the MCL group.

Assessment of bone marrow infiltration diagnosed by flow cytometry in canine large B cell lymphoma: prognostic significance and proposal of a cut-off value

The aims of this study were to assess the prognostic significance of bone marrow (BM) infiltration in canine large B cell lymphoma (LBCL) and to establish cut-off values for designating the BM as infiltrated by lymphoid blasts. The degree of BM infiltration by large CD21 positive cells in dogs with LBCL was assessed by flow cytometry (FC) and related to time to progression (TTP) and lymphoma-specific survival (LSS). Forty-six dogs were prospectively enrolled, staged and treated with a dose-intense chemotherapeutic protocol. BM infiltration was directly correlated with peripheral blood infiltration (P=0.001), high lactate dehydrogenase activity (P=0.0024) and substage b disease (P<0.001). In the univariate analysis, there was a significant association between BM infiltration diagnosed by FC and both TTP (P=0.001) and LSS (P<0.001). Substage was the only factor associated with TTP in the multivariate analysis (P=0.002), whereas substage (P<0.001) and anaemia (P=0.008) were associated with LSS. A cut-off of 3% BM infiltration had the strongest prognostic value, since it discriminated between dogs with a poorer prognosis (median TTP 69 days; median LSS 155 days) and dogs with a better prognosis (median TTP 149 days; median LSS 322 days). BM analysis is an essential step in the staging of LBCL. The presence of BM infiltration by FC at diagnosis is a negative prognostic indicator in canine LBCL.

Aggressive B-cell lymphomas: how many categories do we need?

Aggressive B-cell lymphomas are diverse group of neoplasms that arise at different stages of B-cell development and by various mechanisms of neoplastic transformation. The aggressive B-cell lymphomas include many types, subtypes and variants of diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), mantle cell lymphoma and its blastoid variant, and B lymphoblastic lymphoma. Differences in histology, cytogenetic and molecular abnormalities, as well as the relationship with the tumor microenvironment, help define characteristic signatures for these neoplasms, and in turn dictate potential therapeutic targets. Rather than survey the entire spectrum of aggressive B-cell lymphomas, this report aims to identify and characterize important clinically aggressive subtypes of DLBCL, and explore the relationship of DLBCL to BL and the gray zone between them (B-cell lymphoma unclassifiable with features intermediate between DLBCL and BL).

Primary bone marrow lymphoma: an uncommon extranodal presentation of aggressive non-hodgkin lymphomas

Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising elsewhere, although some tumors may arise primarily in the bone marrow microenvironment. Primary bone marrow lymphoma (PBML) is a rare entity whose real boundaries and clinicobiological significance are not well defined. Criteria to diagnose PBML encompass isolated bone marrow infiltration, with no evidence of nodal or extranodal involvement, including the bone, and the exclusion of leukemia/lymphomas that are considered to primarily involve the bone marrow. Twenty-one out of 40 lymphomas retrospectively reviewed by the International Extranodal Lymphoma Study Group from 12 institutions in 7 different countries over a 25-year period fulfilled the inclusion criteria. These cases comprised 4 follicular lymphomas (FLs), 15 diffuse large B-cell lymphomas (DLBCLs), and 2 peripheral T-cell lymphomas, not otherwise specified. The FL cases showed paratrabecular infiltration, BCL2 protein and CD10 expression, and BCL2 gene rearrangement. DLBCL showed nodular infiltration in 6 cases and was diffuse in 9 cases; it also showed positivity for BCL2 protein (9/10) and IRF4 (6/8). Median age was 65 years with male predominance. All but 3 FL patients were symptomatic. Most cases presented with cytopenias and high lactate dehydrogenase. Four patients (3 FL cases and 1 DLBCL case) had leukemic involvement. Most DLBCL patients received CHOP-like or R-CHOP-like regimens. The outcome was unfavorable, with a median overall survival of 1.8 years. In conclusion, PBML is a very uncommon lymphoma with particular clinical features and heterogenous histology. Its recognition is important to establish accurate diagnosis and adequate therapy.