Clinical and prognostic significance of bone marrow involvement in patients with diffuse aggressive B-cell lymphoma

Utility of leukocyte-associated immunoglobulin-like receptor-1 (CD305) in flow cytometric detection of minimal bone marrow involvement by B-cell non-Hodgkin lymphoma

Multicolor flow cytometry (MFC) is crucial in detecting occult or minimal bone marrow (BM) involvement by non-Hodgkin lymphomas (NHL), which may not be detected using trephine biopsy or imaging studies. Detection of low-level BM involvement can be challenging without definite immunophenotypic aberrancies. We studied the utility of CD305 in MFC detection of minimal BM involvement by B-NHL, especially in the absence of aberrancies by commonly used markers. The study included 1084 consecutive BM samples submitted for the staging of B-NHLs (excluding CLL) over two years. Samples were studied for morphological, immunophenotypic, and histopathological assessment. MFC studies were performed using 10-13 color MFC, including CD305-antibody (clone, DX26). Minimal BM involvement was defined with a cutoff of ≤10% lymphoma cells in viable cells on MFC assessment. Of 1084, 148 samples revealed overt morphological involvement by B-NHL and were excluded from analysis. BM samples of 172/936 patients were morphologically negative but revealed involvement using MFC independently. Corresponding trephine biopsy involvement was detected in only 79/172 (45.9%) patients. On MFC, 23/172 samples showed BM involvement with >10% lymphoma cells, and 149/172 (86.6%) samples revealed minimal involvement. In 54/149 (36.24%) samples, lymphoma cells were detected only with aberrant loss of CD305 expression. In 78 of the remaining 95 samples (82.1%), it provided an immunophenotypic aberrancy addition to other markers and supported the results. CD305 is a highly useful marker in the flow cytometric assessment of minimal BM involvement by B-NHL. MFC is a superior modality to trephine biopsy in detecting low-level BM involvement.

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.

Combination of Bone Marrow Biopsy and Flow Cytometric Analysis: The Prognostically Relevant Central Approach for Detecting Bone Marrow Invasion in Diffuse Large B-Cell Lymphoma

Bone marrow (BM) involvement is associated with prognosis in diffuse large B-cell lymphoma (DLBCL), the most prevalent disease subtype of malignant lymphoma. We conducted this multi-institutional retrospective study to investigate the functional association and prognostic values of four BM tests (BM biopsy, BM clot, flow cytometry (FCM), and BM smear). A total of 221 DLBCL patients were enrolled. BM involvement was detected in 17 (7.7%), 16 (7.2%), 27 (12.2%), and 34 (15.4%) patients by BM biopsy, BM clot, FCM, and BM smear, respectively. The consistency between BM biopsy and clot examination was favorable, with a κ coefficient of 0.705, whereas the consistencies among other modalities were poor. In 184 patients treated with the first-line R-CHOP (-like) regimen, BM involvement was associated with shorter progression-free survival (PFS) irrespective of the type of modality for a positive result. Intriguingly, among various single and combinatory modalities, the combination of BM biopsy and FCM had the highest hazard ratio of 3.33 and a c-index of 0.712. In conclusion, our study suggested that the combination of BM biopsy and FCM is the prognostically relevant central approach for BM involvement detection. The other BM examinations also may provide complementary information in clinical settings.

Clinical significance of rituximab infusion-related reaction in diffuse large B-cell lymphoma patients receiving R-CHOP

BACKGROUND/AIMS

This study was to evaluate the clinical significance of infusion-related reaction (IRR) of rituximab in diffuse large B-cell lymphoma (DLBCL) patients who received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) as a first-line chemotherapy.

METHODS

The medical records of 326 patients diagnosed with DLBCL were re trospectively analyzed. Both doctor's progress records and nursing records were reviewed. IRR was graded according to the National Cancer Institute Common Terminology Criteria.

RESULTS

IRR was not associated with overall survival (OS) or progression-free survival (PFS) of DLBCL patients as compared to those who did not have IRR (OS: median 78.0 months vs. 69.0 months, p = 0.700; PFS: median 65.4 months vs. 64.0 months, p = 0.901). IRR grade did not affect OS or PFS. B symptoms was independently associated with IRR (hazard ratio [HR], 1.850; 95% confidence interval [CI], 1.041 to 3.290; p = 0.036). Further, bone marrow involvement was independently associated with re-IRR (HR, 4.904; 95% CI, 0.767 to 3.118; p = 0.029).

CONCLUSION

Our study shows that IRR of rituximab is not associated with OS or PFS of DLBCL patients who received R-CHOP. Furthermore, our study suggests a need for more careful observation for IRR in patients with B symptoms or bone marrow involvement.

Prognostic impact of germinal center B-cell-like and non-germinal center B-cell-like subtypes of bone marrow involvement in patients with diffuse large B-cell lymphoma treated with R-CHOP

The prognostic significances of the germinal center B-cell-like (GCB) and non-germinal center B-cell-like (non-GCB) types of diffuse large B-cell lymphoma (DLBCL) have been reported to be different. We analyzed the effect of the cell of origin (COO) of bone marrow (BM) involvement in patients with DLBCL who were treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in a single institute.The subtype of BM involvement was evaluated in 633 patients who were diagnosed with primary DLBCL and had been treated with R-CHOP. BM trephine biopsies were analyzed, and immunohistochemical staining of CD20, CD79a, and CD3 was performed. Additional staining of CD10, Bcl-6, and MUM1 was performed to determine the COO based on a previously reported algorithm.BM involvement was present in 81 patients (12.8%). Among them, 30 patients (37.0%) had GCB-type BM involvement and 51 (63.0%) showed non-GCB-type involvement. Kaplan-Meier survival analysis showed that the non-GCB type had the worst progression-free survival (PFS) and overall survival (OS) (P <.001). In multivariate analysis controlled for the International Prognostic Index (IPI) score, non-GCB type was an independent predictor of PFS (P <.004) and OS (P =.042), whereas GCB type was not a prognostic factor independent of the IPI score.Further prognostication based on the COO of BM involvement is a useful indicator of PFS, independent of IPI score. Accurate staging based on the COO should be included in the examination of BM in DLBCL.

B-Cell Lymphoma Patient-Derived Xenograft Models Enable Drug Discovery and Are a Platform for Personalized Therapy

Purpose: Patients with B-cell lymphomas often relapse after frontline therapy, and novel therapies are urgently needed to provide long-term remission. We established B-cell lymphoma patient-derived xenograft (PDX) models to assess their ability to mimic tumor biology and to identify B-cell lymphoma patient treatment options.Experimental Design: We established the PDX models from 16 patients with diffuse large B-cell lymphoma, mantle cell lymphoma, follicular lymphoma, marginal zone lymphoma, or Burkitt lymphoma by inoculating the patient tumor cells into a human bone chip implanted into mice. We subjected the PDX models to histopathologic and phenotypical examination, sequencing, and drug efficacy analysis. Primary and acquired resistance to ibrutinib, an oral covalent inhibitor of Bruton tyrosine kinase, were investigated to elucidate the mechanisms underlying ibrutinib resistance and to identify drug treatments to overcome resistance.Results: The PDXs maintained the same biological, histopathologic, and immunophenotypical features, retained similar genetic mutations, and produced comparable drug responses with the original patient tumors. In the acquired ibrutinib-resistant PDXs, PLC-γ2, p65, and Src were downregulated; however, a PI3K signaling pathway member was upregulated. Inactivation of the PI3K pathway with the inhibitor idelalisib in combination with ibrutinib significantly inhibited the growth of the ibrutinib-resistant tumors. Furthermore, we used a PDX model derived from a clinically ibrutinib-relapsed patient to evaluate various therapeutic choices, ultimately eliminating the tumor cells in the patient's peripheral blood.Conclusions: Our results demonstrate that the B-cell lymphoma PDX model is an effective system to predict and personalize therapies and address therapeutic resistance in B-cell lymphoma patients. Clin Cancer Res; 23(15); 4212-23. ©2017 AACR.

Prognostic significance of bone marrow infiltration detected by PET-CT in newly diagnosed diffuse large B cell lymphoma

The aim of this study was to examine the prognostic value of bone marrow involvement (BMI) assessed by baseline PET-CT (PET(0)-BMI) in treatment-naïve patients with diffuse large B-cell lymphoma (DLBCL). All patients from a single centre diagnosed as DLBCL between 2005 and 2014 had data extracted from staging PET-CT (PET(0)-CT), bone marrow biopsy (BMB), and treatment records. The PET(3)-CT (PET-CT scan after cycle 3 of immunochemotherapy) was performed on all the patients with PET(0)-BMI positivity (PET(0)-BMI(+)). Of 169 patients, 20 (11.8%) had BMI on BMB, whereas 35 (20.7%) were PET(0)-BMI positive. Among PET(0)-BMI(+) patients, patients with maximum of standard uptake value (SUVmax) of bone marrow (SUVmax(BM)) more than 8.6 were significantly associated with high IPI score (3–5) (P=0.002), worse progression-free survival (PFS) and overall survival (OS) (P=0.025 and P=0.002, respectively). In the 68 stage IV cases, 3-year OS was higher in the patients with negative PET(0)-BMI (PET(0)-BMI(−)) than that with PET(0)-BMI(+) (84.2%±6.5% vs. 44.1%±8.6%; P=0.003), while 3-year PFS only shown a trend of statistic significance (P=0.077) between the two groups. Among the 69 patients of inter-risk of IPI (2–3), patients with PET(0)-BMI(+) had significantly inferior PFS and OS than that with PET(0)-BMI(−) (P=0.009 and P<0.001, respectively). The cut-off value of the decreased percentage of SUVmax(BM) between PET(0)-CT and PET(3)-CT (ΔSUVmax(BM)) was 70.0%, which can predict PFS (P=0.003) and OS (P=0.023). These data confirmed that along with the increased sensitivity and accuracy of identifying bone marrow by PET-CT, novel prognostic values of marrow involvement were found in patients with DLBCL.

Assessment of bone marrow involvement in patients with lymphoma: report on a consensus meeting of the Korean Society of Hematology Lymphoma Working Party

In September 2011, the Korean Society of Hematology Lymphoma Working Party held a nationwide conference to establish a consensus for assessing bone marrow (BM) involvement in patients with lymphoma. At this conference, many clinicians, hematopathologists, and diagnostic hematologists discussed various topics for a uniform consensus in the evaluation process to determine whether the BM is involved. Now that the discussion has matured sufficiently to be published, we herein describe the consensus reached and limitations in current methods for assessing BM involvement in patients with lymphoma.

The prognostic significance of monoclonal immunoglobulin gene rearrangement in conjunction with histologic B-cell aggregates in the bone marrow of patients with diffuse large B-cell lymphoma

Bone marrow involvement (BMI) is a well‐known poor prognostic factor in patients with diffuse large B‐cell lymphoma (DLBCL). This study robustly investigated the significance of monoclonal immunoglobulin gene rearrangement combined with histologic B‐cell aggregates in bone marrow (BM) in the detection of a poor prognostic group. Pretreatment BM samples of 394 DLBCL patients were analyzed via the immunoglobulin gene rearrangement study and the microscopic examination. Monoclonal immunoglobulin gene rearrangement was detected in 25.4% of cases. Histologic B‐cell aggregates with the features of large B‐cell lymphoma aggregates, small cell B‐cell lymphoma aggregates, or B‐cell aggregates of unknown biological potential were observed in 12% of cases (6.9%, 1.3%, and 3.8%, respectively). Histologic B‐cell aggregates were more associated with monoclonality than polyclonality. Cases with both monoclonality and histologic B‐cell aggregates demonstrated close association with poor prognostic factors such as a higher International Prognostic Index score and showed an inferior overall survival rate when compared to cases with only monoclonality or only histologic B‐cell aggregates. From the findings, a combination of monoclonality and histologic B‐cell aggregates within the bone marrow was highly associated with poor prognosis and could be used to determine high‐risk DLBLC patients with greater sensitivity and specificity than conventional microscopic examination or immunoglobulin gene rearrangement study alone.

Activation of the polycomb repressive complex pathway in the bone marrow resident cells of diffuse large B-cell lymphoma patients

The present study investigated the activation of polycomb repressive complex 2 (PRC2) pathway proteins in the resident cells within the bone marrow hematopoietic microenvironment of diffuse large B-cell lymphoma (DLBCL) patients. PRC2 proteins (enhancer of zeste homolog 2, suppressor of zeste 12 homolog, and embryonic ectoderm development), histone methylation mark (H3K27me3), and c-MYC activation were evaluated in pretreatment bone marrow from 208 DLBLC patients. Positive expression of the PRC2, H3K27me3, and c-MYC in the bone marrow resident cells was more frequent in cases with bone marrow involvement of tumor. The expression among PRC2, H3K27me3 mark, and c-MYC was closely correlated. Positive PRC2 expression in bone marrow resident cells was significantly associated with inferior progression-free survival (PFS) and overall survival (OS) and determined to be an independent prognostic factor of inferior PFS and OS. In conclusion, the PRC pathway was frequently activated in bone marrow resident cells of DLBCL patients, and PRC activation was tumor-related and associated with poor clinical outcomes.

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.

Patterns of neutropenia and risk factors for febrile neutropenia of diffuse large B-cell lymphoma patients treated with rituximab-CHOP

Febrile neutropenia (FN) is the major toxicity of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen in the treatment of diffuse large B-cell lymphoma (DLBCL). The prediction of neutropenia and FN is mandatory to continue the planned R-CHOP therapy resulting in successful anti-cancer treatment. The clinical features and patterns of neutropenia and FN from 181 DLBCL patients treated with R-CHOP were analyzed retrospectively. Sixty percent (60.2%) of patients experienced at least one episode of grade 4 neutropenia. Among them, 42.2% of episodes progressed to FN. Forty-eight percent (48.8%) of patients with FN was experienced their first FN during the first cycle of R-CHOP. All those patients never experienced FN again during the rest cycles of R-CHOP. Female, higher stage, international prognostic index (IPI), age ≥65 yr, comorbidities, bone marrow involvement, and baseline serum albumin ≤3.5 mg/dL were significant risk factors for FN by univariate analysis. Among these variables, comorbidities (P=0.009), bone marrow involvement (P=0.006), and female gender (P=0.024) were independent risk factors for FN based on multivariate analysis. On observing the patterns of neutropenia and FN, primary prophylaxis of granulocyte colony-stimulating factor (G-CSF) and antibiotics should be considered particularly in female patients, patients with comorbidities, or when there is bone marrow involvement of disease.

Staging DLBCL: bone marrow biopsy or PET-CT?

In this issue of Blood, Khan and colleagues evaluated the clinical implications of marrow involvement identified by FDG-PET-CT (2-[¹⁸F]fluoro-2-deoxy-D-glucose-positron emission tomography combined with computed tomography) vs iliac crest biopsy in newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL). They showed that FDG-PET-CT scanning had a higher level of accuracy for identifying marrow disease than bone marrow (BM) biopsy (BMB). Nevertheless, the identification of BM involvement by histology per se still had a prognostic impact in terms of overall survival (OS) and progression-free survival (PFS).

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.

Prognostic impact of extranodal involvement in diffuse large B-cell lymphoma in the rituximab era

BACKGROUND

Extranodal involvement is considered a poor prognostic factor for patients with diffuse large B-cell lymphoma (DLBCL); however, the prognostic impact of specific sites of involvement has not been fully elucidated.

METHODS

The authors retrospectively analyzed 1221 patients treated uniformly with standard R-CHOP therapy between 2003 and 2006. Patients with distinct forms of DLBCL such as intravascular lymphoma, primary effusion lymphoma, pyothorax-associated lymphoma, primary central nervous system lymphoma, and intraocular lymphoma were also excluded. The authors evaluated 26 extranodal sites of involvement with respect to prognostic impact. The median age was 64 years (range, 15-91 years).

RESULTS

Univariate analysis revealed that patients with involvement of specific extranodal sites had significantly worse overall survival (OS) than did patients without such involvement; these sites included nasal cavity, paranasal sinus, lung, pleura, small intestine, peritoneum, liver, pancreas, stomach, spleen, adrenal gland, testis, bone, bone marrow, peripheral blood, skin, and subcutaneous tissue. Patients with Waldeyer ring involvement had significantly better OS. Multivariate analysis revealed that patients with the involvement of the pleura (P < .001), small intestine (P = .015), peritoneum (P = .002), adrenal gland (P < .001), testis (P = .005), bone marrow (P < .001), and peripheral blood (P = .002) had significantly worse OS, whereas those with Waldeyer ring involvement had significantly better OS (P = .038). Subgroup analysis with the nodal and/or Waldeyer patient group also showed prognostic impact of Waldeyer ring by multivariate analysis (relative risk, 0.3; P = .04).

CONCLUSIONS

Extranodal involvement affects the prognosis of patients undergoing R-CHOP therapy for DLBCL.

Impact of Concordant and Discordant Bone Marrow Involvement on Outcome in Diffuse Large B-Cell Lymphoma Treated With R-CHOP

Purpose

In diffuse large B-cell lymphoma (DLBCL), prior studies suggest that concordant bone marrow involvement with DLBCL portends a poorer prognosis, whereas discordant bone marrow involvement with small B-cell lymphoma does not. We examined the significance of bone marrow involvement in patients treated in the current era of therapy including rituximab.

Patients and Methods

We performed a retrospective analysis of the prognostic impact of bone marrow involvement in an unselected population of patients with newly diagnosed DLBCL treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone in British Columbia and Auckland, New Zealand, with complete clinical information and evaluable staging bone marrow biopsies.

Results

In total, 795 patients were identified. Six hundred seventy (84.3%) of 795 had a negative bone marrow, 67 patients (8.4%) had concordant and 58 (7.3%) had discordant involvement. Median follow-up was 41 months (range, 1 to 115). Progression-free survival (PFS) was inferior in those with concordant (P < .001) and discordant (P = .019) involvement while overall survival (OS) was inferior in those with concordant involvement (P < .001) only. In a multivariate analysis controlling for the International Prognostic Index (IPI) score, concordant involvement remained an independent predictor of PFS (P < .001) and OS (P = .007). Discordant involvement was associated with older age, elevated lactate dehydrogenase, advanced stage, and increased number of extranodal sites and was not a negative prognostic factor independent of the IPI score.

Conclusion

The negative prognostic impact of discordant involvement is adequately represented by the IPI score, while the risk with concordant involvement is greater than that encompassed by this predictor. The results emphasize the need for accurate staging assessment of bone marrow involvement in DLBCL.

If it is in the marrow, is it also in the blood? An analysis of 1,000 paired samples from patients with B-cell non-Hodgkin lymphoma

Background

Staging of B-cell non Hodgkin's lymphoma (NHL) routinely involves bone marrow (BM) examination by trephine biopsy (BM-TB). The evidence of disease in the BM-TB results in a clinical stage IV classification affecting therapeutic strategies for NHL patients. BM immunophenotyping by flow cytometry (FC) is also used, although its clinical value is still under debate.

Methods

Using FC we analyzed 1,000 paired BM aspirates and peripheral blood (PB) samples from 591 NHL patients to investigate the concordance between BM and PB. B-lymphocytes were defined monoclonal when a ratio of 0.3 < κ/l > 3 was observed. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. BM-TB was also performed in 84.1% of samples (841/1000), and concordance between BM-TB and BM-FC was evaluated. Concordance was defined as the presence of a positive (in terms of disease detection) or negative result in both BM-FC and PB-FC or BM-TB and BM-FC.

Results

Using FC, the overall concordance between BM and PB was 95%. Among the discordant cases (ie presence of neoplastic B-lymphocyte in the BM but under the sensibility of the technique in the PB) the most frequent diagnosis was Waldenstrom's macroglobulinemia (WM, accounting for 20.8% of all discordant cases). The expression of CXCR4, a receptor involved in B-cell trafficking and homing, was found to be down regulated in WM compared to other NHL types, thus suggesting a possible role of CXCR4 in WM cell homing in the BM. WM excluded, FC investigation of BM and PB in NHL patients gives overlapping information.

BM involvement was observed by FC in 38% of samples, and concordance between BM-FC and BM-TB was 85%.

Conclusions

The finding that FC data from BM and PB samples overlap in NHL might have major implications for the design of future clinical studies and for patients' follow-up.

Staging bone marrow in diffuse large B-cell lymphoma: the role of ancillary investigations

Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin's lymphoma (NHL) that requires treatment at initial diagnosis. Treatment decisions may be guided by staging investigations, which include assessment of bone marrow (BM). Traditionally this assessment has included light microscopic examination of the bone marrow aspirate and trephine biopsy. Ancillary testing--including immunophenotyping using flow cytometry on BM aspirates, immunohistochemistry (IHC) on BM trephines and molecular studies using immunoglobulin heavy (IgH) or light (IgL) chain gene rearrangements--are performed as required to aid histological diagnosis. This review examines the evidence for the routine use of ancillary tests in the initial staging of DLBCL, including the limitations, potential pitfalls and possible clinical implications of their use in this setting.

Lack of utility of CD20 immunohistochemistry in staging bone marrow biopsies for diffuse large B-cell lymphoma

The utility of CD20 immunohistochemistry in the evaluation of staging bone marrow biopsies of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients has not been extensively studied. We used 113 routinely processed bone marrow biopsies to study the extent and pattern of involvement by lymphoma and CD20 staining. Twelve (10.6%) of 113 cases had involvement by morphology, and 5 (41.7%) of these showed histologic discordance between the primary site and the bone marrow. All cases with morphologic evidence of bone marrow involvement showed staining for CD20. Four (3.5%) of 113 cases had non-neoplastic aggregates that stained for CD20. One case (0.9%) showed a small benign lymphoid aggregate by immunohistochemistry that was not evident by morphology. Our results demonstrate that CD20 staining did not detect any examples of bone marrow involvement by DLBCL that were not evident by morphology. We conclude that immunohistochemistry for CD20 adds no increase in the sensitivity of detection of bone marrow infiltration by DLBCL.

Role of immunohistochemistry in staging diffuse large B-cell lymphoma (DLBCL)

The use of immunohistochemistry (IHC) in staging bone marrow in non-Hodgkin's lymphoma (NHL) is largely limited to ambiguous cases, particularly those with lymphoid aggregates. Its role in routine clinical practice remains unestablished. This study aimed to determine whether the routine use of IHC in diffuse large B-cell lymphoma (DLBCL) would improve the detection of lymphomatous involvement in the bone marrow. It also sought to determine the impact of IHC on predicting survival compared with routine histological diagnosis using hematoxylin and eosin (H&E), Giemsa, and reticulin staining. The bone marrow trephines of 156 histologically proven DLBCL cases were assessed on routine histology, and IHC using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a), and kappa and lambda light chains. IHC detected lymphomatous involvement on an additional 11% cases compared with histology alone. Although both routine histology and IHC were good predictors of survival, IHC was better at predicting survival on stepwise multivariate Cox regression analysis. IHC performed routinely on bone marrow trephines has the ability to improve detection of occult lymphoma in experienced hands. Furthermore, it is a better predictor of survival compared with routine histological examination alone.

Concordant but not discordant bone marrow involvement in diffuse large B-cell lymphoma predicts a poor clinical outcome independent of the International Prognostic Index

In diffuse large B-cell lymphoma (DLBCL), previous studies have suggested that, while concordant bone marrow (BM) involvement confers a poor prognosis, discordant BM involvement does not. Whether this correlation is independent of the non-Hodgkin lymphoma International Prognostic Index (IPI) was previously unknown. We reviewed all DLBCL case histories from 1986 to 1997 at our center with complete staging, IPI data, and follow-up. A total of 55 (11.2%) of 489 patients had BM involvement, including 29 with concordant involvement and 26 with discordant involvement. The 55 patients with BM involvement had a poor prognosis compared with the uninvolved BM group (5-year overall survival [OS], 34.5% versus 46.9%; log-rank P = .019). However, concordant involvement portended a very poor prognosis (5-year OS, 10.3%; P < .001), whereas discordant involvement did not (5-year OS, 61.5%, P value nonsignificant). Compared with the discordant subset, the concordant subset patients were older, had a higher serum lactate dehydrogenase level, and a significantly higher IPI. However, the poor survival associated with concordant BM involvement was independent of the IPI score (P = .002, Cox regression). We conclude that in patients with DLBCL, concordant but not discordant BM involvement confers a very poor clinical outcome. Furthermore, concordant BM involvement is an independent adverse prognostic factor.

Prospective study of bone marrow infiltration in aggressive lymphoma by three independent methods: whole-body MRI, PET/CT and bone marrow biopsy

PURPOSE

Initial lymphoma staging requires bone marrow assessment in aggressive lymphomas. Bone marrow lymphoma infiltration is routinely assessed by bone marrow biopsy (BMB), considered as the "gold standard". The aim of this study was to compare the performance of BMB, whole-body MRI and PET/CT for evaluation of BM infiltration.

METHODS

Patients with newly diagnosed aggressive lymphoma were evaluated by BMB, MRI and PET/CT. Two radiologists, two nuclear medicine physicians and one pathologist independently assessed the results of the three modalities. Bone was considered as involved if BM was positive or if PET/CT or MRI was positive and if there was a resolution of the abnormal image shown on PET/CT or MRI halfway or at the end of therapy.

RESULTS

Both MRI and PET/CT detected bone marrow lesions in the 9/43 patients, but two patients with multiple lesions had more lesions detected by PET/CT compared to MRI. Among these nine patients, two with an iliac crest lesion detected by both MRI and PET/CT had bone marrow involvement with large-cell lymphoma on histological examination. The other seven patients had focal MRI and PET/CT lesions in areas other than the iliac crest, where the blind BMB was done. The other patients had bone marrow without large-cell lymphoma involvement. In all cases, after lymphoma therapy bone marrow involvement regressed on histological examination, PET and MRI.

CONCLUSION

These preliminary results suggest that non-invasive morphological procedures could be superior to BMB for bone marrow assessment in aggressive lymphomas. Ongoing study is underway to validate these results.

Prolonged survival in poor-risk diffuse large B-cell lymphoma following front-line treatment with rituximab-supplemented, early-intensified chemotherapy with multiple autologous hematopoietic stem cell support: a multicenter study by GITIL (Gruppo Italiano Terapie Innovative nei Linfomi)

A prospective multicenter program was performed to evaluate the combination of rituximab and high-dose (hd) sequential chemotherapy delivered with multiple autologous peripheral blood progenitor cell (PBPC) support (R-HDS-maps regimen) in previously untreated patients with diffuse large B-cell lymphoma (DLB-CL) and age-adjusted International Prognostic Score (aaIPI) score 2-3. R-HDS-maps includes: (i) three APO courses; (ii) sequential administration of hd-cyclophosphamide (CY), hd-Ara-C, both supplemented with rituximab, hd-etoposide/cisplatin, PBPC harvests, following hd-CY and hd-Ara-C; (iii) hd-mitoxantrone (hd-Mito)/L-Pam + 2 further rituximab doses; (iv) involved-field radiotherapy. PBPC rescue was scheduled following Ara-C, etoposide/cisplatin and Mito/L-Pam. Between 1999 and 2004, 112 consecutive patients aged <65 years (74 score 2, 38 score 3) entered the study protocol. There were five early and two late toxic deaths. Overall 90 patients (80%) reached clinical remission (CR); at a median 48 months follow-up, 87 (78%) patients are alive, 82 (73%) in continuous CR, with 4 year overall survival (OS) and event-free survival (EFS) projections of 76% (CI 68-85%) and 73% (CI 64-81%), respectively. There were no significant differences in OS and EFS between subgroups with Germinal-Center and Activated B-cell phenotype. Thus, life expectancy of younger patients with aaIPI 2-3 DLB-CL is improved with the early administration of rituximab-supplemented intensive chemotherapy compared with the poor outcome following conventional chemotherapy.

The prognostic impact of bone marrow involvement in patients with diffuse large cell lymphoma varies according to the degree of infiltration and presence of discordant marrow involvement

BACKGROUND

The prognostic significance of marrow involvement in diffuse large cell lymphoma (DLCL) is controversial. Factors that that have been reported to influence prognosis include the pattern and extent of marrow infiltration and histological discordance between the primary site and the bone marrow.

METHODS

Bone marrow biopsies from 172 patients with newly diagnosed DLCL entered in two consecutive trials of the Australasian Leukaemia and Lymphoma Group were analyzed. Progression-free (PFS) and overall survival (OS) were calculated according to the absence or presence of bone marrow involvement (BMI), the extent of lymphomatous infiltration and the presence of histological discordance between the primary site and the bone marrow.

RESULTS

Of 172 patients with DLCL accrued between 1982 and 1990, who were treated with CHOP or CHOP-like regimens, 47 (27%) demonstrated marrow involvement on examination of multiple levels. Seventy two percent (34/47) of patients had discordant marrow involvement (<50% large cells) and 28 had minimal (<10%) involvement; these latter patients with minimal marrow involvement (<10%) had similar PFS & OS to the 113 patients without involvement. Within the group of 47 patients with marrow involvement, an increasing percentage of BM involvement was significantly associated with an increasing percentage of concordant histology and a decreasing PFS & OS.

CONCLUSIONS

Minimal BMI, seen in the majority of patients with DLCL with marrow infiltration, appears not to influence the PFS & OS. However, an increasing degree of marrow involvement is associated with an increasing component of large cells and a poorer prognosis in DLCL patients, independent of other risk factors.

Clinical utility of bone marrow flow cytometry in B-cell non-Hodgkin lymphomas (B-NHL)

AIM

To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated.

METHODS AND RESULTS

Morphological analysis and FC immunophenotyping were performed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard kappa/lambda/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances.

CONCLUSIONS

Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients.

Hodgkin and non-Hodgkin lymphoma involving bone marrow

The role of bone marrow examination in diagnosis and staging of patients with Hodgkin lymphoma, B-non-Hodgkin lymphoma, and T-non-Hodgkin lymphoma is reviewed. Optimal routine and specialized bone marrow examination techniques are discussed. The salient morphologic, immunophenotypic, and genetic features of mature and immature B, T neoplasms and classic Hodgkin lymphoma in bone marrow are delineated, along with recommendations to distinguish these overt neoplasms from non-neoplastic processes.

T-cell-rich B-cell lymphoma: a clinicopathologic study of 21 cases and comparison with 43 cases of diffuse large B-cell lymphoma

Clinicopathologic features of 21 patients with T-cell-rich B-cell lymphoma (TCRBCL) were reviewed and compared to 43 patients with diffuse large B-cell lymphoma (DLBCL) to determine if there were distinguishing clinical characteristics and differences in response or survival to CHOP therapy. For the diagnosis of TCRBCL, the current WHO criteria was used. In all of our cases, the majority of cells are non-neoplastic T cells and <10% large neoplastic B cells are present. The initial pathologic diagnosis was nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) in two cases. Patients with TCRBCL were significantly younger (median: 46 years) and had a significantly higher incidence of B symptoms (62%), hepatomegaly (33%) and marrow infiltration (33%) at presentation when compared to DLBCL (P<0.03). The CR rate after treatment was 48% for TCRBCL patients versus 79% for the DLBCL (P<0.003). Although the CR rates in between the two groups are significant, the difference in 3 years survival rates in each CR groups was insignificant (80% versus 77%). The overall survival time in the two groups was 17 months. Event-free survival time in TCRBCL was 12 months, compared with 17 months in the DLBCL (P>0.05). The frequency of patients with TCRBCL achieving CR was 52.6% whereas that of patients with DLBCL was 79% (P<0.003). The TCRBCL 3 years event-free survival 48% and overall survival 64% were 63 and 72% for DLBCL, respectively.

Primary non-Hodgkin's lymphoma of the bladder with bone marrow involvement

Involvement of the lower urinary tract by advanced non-Hodgkin's lymphoma (NHL) has been reported in up to 13% of cases, but primary NHL of the urinary bladder is very rare. A 35-year-old man was admitted to our hospital with a chief complaint of gross hematuria with left flank pain on April 12, 2001. Cystoscopy revealed an edematous broad-based mass on the left lateral wall of the bladder, and transurethral biopsy showed NHL, diffuse large B-cell type. Abdomino-pelvic CT scan demonstrated left-side hydronephrosis and hydroureter with left proximal ureter infiltration and thickening of the left lateral wall of the bladder with perivesical fat infiltration without lymph node enlargement. Full-scale staging work-up revealed the bone marrow as the solely involved site. The lesions of the bladder and left urinary tract were nearly completely regressed after two cycles of systemic cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy with simultaneous restoration of urinary function.

Optimum trephine length in the assessment of bone marrow involvement in patients with diffuse large cell lymphoma

BACKGROUND

The National Cancer Institute has recommended a bone marrow biopsy length of >/=20 mm for the staging and surveillance of patients with non-Hodgkin's lymphoma. However, there are few published data to support this recommendation, particularly the role of examining multiple levels.

PATIENTS AND METHODS

Bone marrow biopsies from 172 patients with newly diagnosed diffuse large cell lymphoma (DLCL) entered in two consecutive trials of the Australasian Leukaemia and Lymphoma Group were analysed. The original haematoxylin and eosin-stained trephine biopsy and two or more deeper sections cut at 0.1-0.2 mm intervals were assessed with respect to the morphology, extent and pattern of lymphomatous involvement. The rate of positive diagnosis was correlated with the length of the biopsy specimen and the number of sections examined.

RESULTS

Forty-seven biopsies (27%) demonstrated marrow involvement on examination of a mean of four trephine biopsy sections. The rate of positivity increased with the examination of multiple levels and correlated with increasing trephine length but was not dependent on the number of sites sampled. Twenty per cent of biopsies <20 mm in length were positive for lymphoma; this increased to 35% for biopsies >/=20 mm (P = 0.023).

CONCLUSIONS

Morphological bone marrow involvement in DLCL is optimally demonstrated by a 20-mm long trephine biopsy from a single site which is examined at multiple levels (four or more). This obviates the need for bilateral sampling, thereby reducing patient morbidity from the procedure. This study provides evidence to support the National Cancer Institute recommendations regarding trephine biopsy in the staging of DLCL, providing multiple levels are examined.

Polymerase chain reaction-based diagnosis of bone marrow involvement in 170 cases of non-Hodgkin lymphoma

BACKGROUND

Up to the current time, diagnosis of bone marrow (BM) involvement in non-Hodgkin lymphoma (NHL) has been based on morphologic findings. Polymerase chain reaction (PCR) for antigen receptor gene rearrangements has the potential to increase the detection sensitivity of minimal degrees of BM involvement. The authors therefore assessed PCR-based clonalities of BM concurrently with morphology from 170 cases with NHL and evaluated the usefulness of comparative analysis of clonalities between bilateral BMs and the lymph node and the clinical significance of PCR based clonalities of BM.

METHODS

Bilateral BM clot sections of 170 cases and 47 lymph nodes were tested for immunoglobulin heavy chain gene rearrangement or T-cell receptor gamma gene rearrangement according to the B- or T-lineage of the lymph node.

RESULTS

When compared with morphology, the results of PCR showed an unexpectedly low positive concordance rate of 61.0% for B-cell NHL and 57.1% for T-cell NHL. When the clonality of BM was compared with that of lymph nodes in B-cell NHL, bilateral clonalities of BM showed high concordance with the clonality of the lymph nodes. PCR-based clonality did not show significant impact on survival.

CONCLUSIONS

Morphology remains the gold standard in the evaluation of BM involvement by NHL. Although the comparative analysis of BM clonality and that of the lymph nodes is considered a valuable tool that increases the reliability of clonality, PCR-based clonality of BM does not significantly add to the sensitivity of diagnosing BM involvement by NHL.

Diagnostic utility of bilateral bone marrow examination: significance of morphologic and ancillary technique study in malignancy

BACKGROUND

To retrospectively evaluate the significance of morphologic examination and ancillary studies performed on bilateral bone marrow biopsy specimens, 1864 bone marrow samples were studied.

METHODS

Bilateral bone marrow biopsy specimens included 883 specimens that were evaluated for involvement by non-Hodgkin lymphoma (NHL); 381 specimens that were evaluated for involvement by carcinoma (CA); 362 specimens that were evaluated for involvement by Hodgkin disease (HD); 94 specimens that were evaluated for involvement by sarcoma (SA); 56 specimens that were evaluated for involvement by multiple myeloma (MM); 53 specimens that were evaluated for involvement by acute and chronic leukemia, myelodysplasia, and/or myeloproliferative disorders (LEUK); and 35 specimens that were evaluated for other reasons.

RESULTS

Of all 1864 specimens, 410 samples (22.0%) were positive for disease, including 77% of MM samples, 58% of LEUK samples, 29.6% of NHL samples, 14% of SA samples, 9.9% of HD samples, and 6.8% of CA samples. A discrepancy between the left and right sides was identified in 48 specimens (11.7% of positive samples). The discrepancy rate was 39% for HD samples, 29% for SA samples, 23% for CA samples, and 9.2% for NHL samples. No morphologic discrepancies between bilateral samples were found in MM samples or LEUK samples. Bilateral flow cytometric studies (n = 113 samples) were positive in 11 samples (9.7%; all morphologically positive), with two discrepancies detected between bilateral samples. Bilateral cytogenetic studies (n = 74 samples) were positive in 5 samples (7%), and there were no discrepancies. Bilateral molecular studies (n = 16 samples) were positive in 7 samples (44%), and there were 3 discrepancies.

CONCLUSIONS

Bilateral morphologic evaluation is useful in the evaluation of patients with NHL, HD, CA, and SA and is not indicated for patients with acute or chronic leukemia, myelodysplasia, MM, and other diseases. Bilateral flow cytometric or cytogenetic studies of bone marrow did not provide additional information in this population to justify bilateral samples. The role of bilateral molecular analysis needs to be defined further, but pooled samples for molecular studies may be adequate.

T-cell/histiocyte-rich large B-cell lymphoma: a distinct clinicopathologic entity

PURPOSE

Although it has proven difficult to delineate diagnostically reproducible and clinically relevant subgroups, the heterogeneity of diffuse large B-cell lymphomas (DLBCL) is widely acknowledged. In 1992, we reported on six cases that suggested that large B-cell lymphoma rich in stromal histiocytes and T cells may be identified as a distinct clinicopathologic entity within DLBCL.

PATIENTS AND METHODS

An integrated clinicopathologic study of 40 cases of this DLBCL subtype is presented.

RESULTS

Distinguishing a DLBCL rich in histiocytes and reactive T cells, designated T-cell/histiocyte--rich large B-cell lymphoma (THR-BCL), may be justified from a clinical point of view. The disease typically affects middle-aged male patients who usually present with advanced-stage disease that is not adequately managed with current therapeutic strategies. Whereas proliferation fraction and p53 overexpression, in addition to the clinical variables incorporated in the International Prognostic Index (IPI), significantly correlate with response to treatment and survival in a univariate analysis, only the IPI score identifies relevant prognostic THR-BCL subpopulations in a multivariate model. The morphologic and immunophenotypic profile of the neoplastic B cells in THR-BCL suggests that they may originate from a germinal center ancestor.

CONCLUSION

THR-BCL constitutes a distinct clinicopathologic entity that is characterized by an aggressive behavior. Experimental therapeutic strategies may be indicated to obtain a more favorable response to treatment in this disease.

Clinical, immunologic, and pathologic correlates of bone marrow involvement in 291 patients with acquired immunodeficiency syndrome-related lymphoma

Bone marrow involvement is reported in approximately 25% of patients with newly diagnosed acquired immunodeficiency syndrome-related lymphoma (ARL). Studied were 291 patients with ARL, diagnosed and treated at one medical center between 1984 and 1998. Clinical, immunologic, and pathologic characteristics of patients with bone marrow involvement were compared with those of patients without marrow involvement. Bone marrow involvement was present in 55 patients (19%). Small noncleaved lymphoma was diagnosed in 38% of the entire group and was the most common pathologic subtype in patients with bone marrow involvement (55% versus 34%; P =.008). Analysis of complete blood counts revealed a median hemoglobin level of 10.6 g/dL in both marrow-positive and marrow-negative groups. In contrast, a platelet count lower than 100 000/microL was more common in patients with bone marrow involvement (27% versus 11%; P =.02). Patients with marrow involvement were more likely to have leptomeningeal (cerebrospinal fluid [CSF]) lymphoma than patients whose marrows were uninvolved (24% versus 7%; P <.001) and were also more likely to have high lactate dehydrogenase (LDH) (P =.002), bone involvement (P <.001), and/or systemic B symptoms including fever, night sweats, and/or weight loss (P =.05). Median survival did not differ between marrow-positive and marrow-negative groups. On multivariate analysis, factors associated with decreased survival of marrow-positive patients included greater than 50% involvement (P =.002), systemic B symptoms (P =.008), and high-grade histologic type (P =.035). Marrow involvement in ARL correlates with small noncleaved pathology, thrombocytopenia lower than 100 000 mm(3), high LDH, and lymphomatous involvement of the CSF. Survival is statistically shorter in patients with greater than 50% marrow involvement, high-grade pathology, and/or systemic B symptoms.

Immunophenotypic Analysis of Peripheral Blood and Bone Marrow in the Staging of B-Cell Malignant Lymphoma

This study evaluated the contributing roles of flow cytometric immunophenotyping of blood and bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a corresponding blood specimen was also immunophenotyped in 135 of these cases. Morphologic marrow involvement by lymphoma was found in 59 cases; flow immunophenotyping identified 54 cases with a monoclonal B-cell process: morphology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10), morphology-negative/flow-positive (n = 5), and morphology-negative/flow-negative (n = 111). The 10 morphology-positive/flow-negative cases included 5 follicular and 5 large-cell lymphomas with minimal marrow involvement. All 5 morphology-negative/flow-positive cases were from patients with large-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases studied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, mantle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphomas. From our results, we conclude that (1) bone marrow flow cytometric immunophenotyping is not a cost-effective replacement for good morphologic evaluation in lymphoma staging and that (2) a positive peripheral blood flow cytometric immunophenotyping study when performed in low-grade lymphomas correlates with marrow involvement.

Immunophenotypic Analysis of Peripheral Blood and Bone Marrow in the Staging of B-Cell Malignant Lymphoma

This study evaluated the contributing roles of flow cytometric immunophenotyping of blood and bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in the staging of B-cell malignant lymphoma. Flow immunophenotyping was performed on a marrow specimen in 175 cases; a corresponding blood specimen was also immunophenotyped in 135 of these cases. Morphologic marrow involvement by lymphoma was found in 59 cases; flow immunophenotyping identified 54 cases with a monoclonal B-cell process: morphology-positive/flow-positive (n = 49), morphology-positive/flow-negative (n = 10), morphology-negative/flow-positive (n = 5), and morphology-negative/flow-negative (n = 111). The 10 morphology-positive/flow-negative cases included 5 follicular and 5 large-cell lymphomas with minimal marrow involvement. All 5 morphology-negative/flow-positive cases were from patients with large-cell lymphomas and bulky clinical disease. Because the blood contained the same B-cell clone in 2 of 2 morphology-negative/flow-positive cases studied, blood contamination of marrow may account for these findings. Blood flow cytometric immunophenotyping studies were positive in 32 cases; 30 had marrow involvement by morphology and were from patients with follicular, mantle cell, lymphoplasmacytic, small lymphocytic, or marginal zone lymphomas. From our results, we conclude that (1) bone marrow flow cytometric immunophenotyping is not a cost-effective replacement for good morphologic evaluation in lymphoma staging and that (2) a positive peripheral blood flow cytometric immunophenotyping study when performed in low-grade lymphomas correlates with marrow involvement.

Bone marrow involvement in lymphoma: the importance of marrow magnetic resonance imaging

Detection of bone marrow involvement is important for staging and treatment decisions in patients with lymphoma. Although routine bone marrow evaluation is based on aspirates and bone marrow biopsies, new diagnostic tools are required to improve diagnostic accuracy. Visual and quantitative assessment of the bone marrow by magnetic resonance (MR) imaging is useful for the detection of occult lymphomatous marrow involvement. MRI is also suitable for the evaluation of disease extent in the bone marrow. Furthermore, abnormal images on marrow MRI may be associated with a significantly poorer survival in patients with lymphoma, regardless of histologic findings in the marrow. Evaluation of the bone marrow by MRI is essential to assess disease status in patients with lymphoma.

Molecular Monitoring of Minimal Residual Disease in Follicular and Mantle Cell Non-Hodgkin's Lymphomas Treated With High-Dose Chemotherapy and Peripheral Blood Progenitor Cell Autografting

Minimal residual disease (MRD) was evaluated in 30 patients with follicular or mantle cell non-Hodgkin's lymphoma (NHL) undergoing an intensive treatment with high-dose sequential (HDS) chemotherapy and peripheral blood progenitor cell (PBPC) autografting. To minimize the potential tumor cell contamination, PBPC harvests were scheduled at the end of HDS pretransplant phase. All patients had advanced-stage disease and most of them presented with bone marrow (BM) involvement. A tumor marker could be generated in 90% of patients using bcl-2 or Ig heavy-chain genes. MRD was analyzed on PBPC, BM harvests, and after autografting by polymerase chain reaction (PCR). All evaluable follicular and 6 of 9 mantle cell patients achieved clinical complete remission. PCR negativity of PBPC and/or BM harvests was documented in 68% of follicular and 12% of mantle cell lymphomas. Molecular remission of PBPC and/or BM harvests was achieved in 9 of 15 patients with overt marrow involvement and in all patients with only molecular marrow infiltration at onset. Molecular follow-up was conducted on 14 patients: all 7 evaluable patients who received at least one PCR-negative graft maintained the negative status at a median follow-up of 24 months and none of them relapsed so far. Thus, the results show that (1) a molecular marker to monitor MRD can be obtained in most follicular and mantle cell NHL patients, (2) the HDS regimen may provide PCR-negative PBPC and/or BM harvests even from patients with BM disease, and (3) autograft with at least one PCR-negative harvest is associated with a durable clinical and molecular remission.