Indolent Subtypes Research Articles

Clinical Challenges of Primary Diffuse Large B-Cell Lymphoma of the Dura: Case Report and Literature Review

Primary dural lymphoma is a rare disease with more indolent clinical behavior compared to primary central nervous system lymphoma. The majority of the reported cases were indolent marginal zone lymphoma subtype with more predilections to the spine. Herein, we are presenting a case of intracranial, diffuse large B-cell lymphoma of the dura that was diagnosed and treated at our institution. We are presenting the challenges in the treatment based on a review of the literature.

The Risk of Secondary Myelodysplastic Syndrome/Acute Leukemia Following High-Dose Yttrium-90 Ibritumomab Tiuxetan Is Analogous to That Observed Following High-Dose Chemotherapy: a Matched-Pair Analysis In Non-Hodgkin Lymphoma Patients.

AbstractAbstract 1289 Introduction:Myeloablative doses of Yttrium-90 (90Y)-Ibritumomab Tiuxetan combined with tandem autologous peripheral blood stem cell (PBSC) support can be safely administered to patients aged up to 76 years (Devizzi L et al, J Clin Oncol 2008). Whether marrow exposure to myeloablative doses of radiolabelled antibodies (hd-radio-immunotherapy) could increase the risk of secondary myelodysplastic syndrome and acute leukemia (sMDS/AL) remains a matter of concern. Therefore, we prospectively investigated by means of a longitudinal study the incidence of sMDS/AL in a cohort of high-risk non-Hodgkin lymphoma (NHL) patients receiving hd-radio-immunotherapy. The cumulative incidence of sMDS/AL in the study group was compared with that observed in a historical group of patients autografted following chemotherapy-based myeloablative conditioning. Additionally, to further investigate marrow damage induced by hd-radio-immunotherapy, hematopoietic and stromal progenitors, as well as telomere length (TL) were assessed. Patients and Methods:From July 2004 through December 2007, 53 relapsed/refractory (n= 36) or de novo high-risk (n= 17) NHL patients (median age, 64 years; range, 26 – 76 years) received a high-dose sequential (HDS) chemotherapy program, including a myeloablative phase with 90Y-Ibritumomab Tiuxetan (1.2 mCi/kg body weight). Patients were monitored for frequency of colony-forming cells (CFCs), cytogenetic and TL analysis. Bone marrow (BM) samples were collected prior to hd-radio-immunotherapy, every six months for two years and annually thereafter. The study was approved by the Institutional Ethical Committee and written informed consent was obtained from each patient. The study group included 29 patients with aggressive lymphoma (diffuse large B-cell lymphoma, n = 19; mantle cell lymphoma, n = 8; Richter syndrome, n = 2) and 24 with indolent NHL subtypes (follicular lymphoma, n = 20; marginal zone lymphoma, n = 3; lymphocytic lymphoma, n = 1). Thirty patients were relapsed after one (n=15) or more (n=15) previous chemotherapy regimens, 6 patients were refractory and 17 patients were previously untreated with high-risk prognostic index. Pre-exposure to alkylating agent involved 68% of the patients. A historical group of 55 NHL patients who received an analogous HDS program with final chemotherapy-based autografting was used as control group. Study and control groups were pair-matched for age, gender, histological subtype, disease status at transplant and type of grafted PBSC. Results:At a median follow-up of 49 months (range, 32 – 74), 4 out of 53 patients of the study group developed sMDS/AL at 6, 12, 27 and 36 months from transplant. According to WHO criteria, refractory anemia with excess of blasts 1 (RAEB-1) was diagnosed in one patient, whereas refractory cytopenia with unilineage dysplasia (RCUD) was diagnosed in the other three cases, with acute leukemia transformation being observed in two patients at 12 and 18 months after initial detection of abnormal cytogenetics, respectively. The cumulative incidence of sMDS/AL resulted of 8.29% at 5-years. An analogous 5-year cumulative incidence of 8.05% was observed in the historical control group autografted following a chemotherapy-based conditioning. Radioimmunotherapy-treated patients showed a significant but transient decrease in granulocyte-macrophage colony forming unit (CFU-GM) at 6 months after transplant, with recovery to baseline values at 12 months. Multilineage colony-forming units (CFU-Mix), erythroid burst-forming units (BFU-E) and fibroblast CFU (CFU-F) were not show significantly affected over time. In contrast, a progressive and significant decrease in BM TL was evident from 12 months after transplant. Conclusion:In our series of elderly NHL patients receiving hd-radio-immunotherapy, the incidence of sMDS/AL was found increased compared to recently reported series of younger lymphoma patients receiving chemotherapy-based conditioning. However, the increased risk of sMDS/AL was not associated with the type of myeloablative conditioning, i.e. chemotherapy vs radio-immunotherapy. Other factors may have favored the development of sMDS/AL, including advanced age at transplant, extensive pre-transplant therapy and type of reinfused PBSC. The observed progressive TL loss gives support to the concept that TL loss might be involved in sMDS/AL development. Disclosures:No relevant conflicts of interest to declare.

Marginal zone B-cell lymphoma of the infratemporal fossa: A rare case and review

Although it represents the second most common neoplasm of the head and neck, lymphoma is generally not surgically managed and thus may be less familiar to otolaryngologists than other malignancies. However, otolaryngologists are often involved in the initial diagnosis, and should be aware of unusual presentations and the main lymphoma subtypes. We present a case of an extranodal marginal zone B-cell lymphoma, an indolent non-Hodgkin's lymphoma subtype. This type of lymphoma most commonly occurs in the stomach, but was found in the infratemporal fossa. This is the first report of an extranodal marginal zone B-cell lymphoma occurring in this location.

Management of non-Hodgkin lymphomas arising at extranodal sites

Primary extranodal lymphomas are relatively rare non-Hodgkin lymphoma presentations with either no or only "minor" nodal involvement along with a clinically "dominant" extranodal component, to which primary treatment must often be directed. Clinical presentations depend largely on the localization and are similar to those of other malignancies affecting that specific organ. In addition to the histological subtype, the primary organ of origin represents the most significant prognostic factor due to differences in natural history and, mainly, in management strategies related to organ-specific problems. In principle, as for primary nodal disease, treatment strategies depends on the patient's clinical conditions, the extent and/or location of the disease, and the histological type. In general, for stage I and II disease with low tumor burden, local therapy is a relevant option both for cure and local control. In advanced stage disease, systemic chemoimmunotherapy is usually required. Localizations with particularly poor survival are the enteropathy-type T-cell lymphoma, the primary testicular diffuse large B-cell lymphoma, and the primary CNS Lymphoma. However, recent studies have shown that site-tailored treatment strategies in testis and brain lymphoma may result in a significant outcome improvement. Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is the most common indolent subtype. This lymphoma usually arises in mucosal sites where lymphocytes are not normally present and where a lymphoid infiltration is acquired in response to either chronic infectious conditions or autoimmune processes: Helicobacter pylori gastritis, Hashimoto's thyroiditis, Sjögren syndrome. Indeed, a pathogenetic link between gastric MALT lymphoma and H. pylori is strongly suggested by the regression of gastric MALT lymphoma (in approx. 75% of cases) after antibiotic eradication of the microorganism.

Expression Profile of Galectin-1 and Galectin-3 Molecules in Different Subtypes of Chronic Lymphocytic Leukemia

ABSTRACTGalectin-1 (Gal-1) and galectin-3 (Gal-3) molecules are involved in many vital, biological, and pathological processes. In this study the expression pattern of these two molecules was investigated in leukemic cells from 85 Iranian chronic lymphocytic leukemia (CLL) patients, classified into indolent, progressive, mutated, and unmutated subtypes by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) and flow cytometry methods. Our results showed significant downregulation of Gal-3, but not Gal-1, in CLL patients compared with normal subjects (p < .001). Higher representation of Gal-3 mRNA was observed in indolent patients compared with the progressive group (p < .05). Our findings imply a regulatory role for Gal-3 gene in initiation and/or progression of CLL.

Epidermodysplasia Verruciformis Associated with Myelodysplastic Syndrome: An Intriguing Association

Epidermodysplasia verruciformis (EV) is a rare genodermatosis characterized by massive infection with human papillomaviruses (HPVs) and development of skin cancer. Myelodysplastic syndromes (MDSs) are a group of chronic conditions that involve dysplastic hematopoiesis, peripheral blood cytopenias, and a high incidence of progression into leukemia. We describe the intriguing association of these two premalignant conditions (EV and MDS) in one patient. These diagnoses were confirmed by histopathologic examination and cytogenetic abnormalities of bone marrow cells. The patient presented initially with clinical features typical of EV and impairment of cell-mediated immunity. In the skin lesions, HPVs 23 and 25 were identified by nested polymerase chain reaction. Six years later, he had recurrent episodes of mucosal bleeding with fever, weakness, and fatigue. At this time, severe refractory anemia and neutropenia were observed, and bone marrow smears showed hypercellularity with abnormal dysplastic megakaryocytes. The cytogenetic pattern showed abnormalities involving trisomy of chromosomes 8 and 21. The patient received a diagnosis of the indolent subtype of MDS. Through the observation of our patient and review of the literature, we hypothesized that the pathomechanisms, including the role of oncogenes and cytokines, are connected to the progression to malignancy in these settings.

Variation in WNT genes expression in different subtypes of chronic lymphocytic leukemia

The Wnt molecules are a family of secretory glycoproteins implicated in proliferation and differentiation of both normal and malignant cells. Despite extensive investigation of the WNT genes expression profile in various tumors, little is known about their expression in chronic lymphocytic leukemia (CLL). In this study, the expression profile of 14 WNT genes was investigated in a large number of Iranian patients with CLL. Semi-quantitative RT-PCR was performed on peripheral blood leukemic cells obtained from 62 patients with CLL. Peripheral blood mononuclear cells isolated from 11 age matched normal subjects served as control to determine baseline expression level of these genes. Our results have demonstrated significant up-regulation of WNT-3, WNT-4, WNT-5B, WNT-7B, WNT-9A, WNT-10A, and WNT-16B in patients with CLL compared to normal subjects (p < 0.05 to p < 0.0001). WNT gene expression analysis in different CLL subtypes showed a similar pattern of expression in progressive and indolent clinical subtypes. Over-expression of WNT-5A and WNT-9A genes was observed in patients with no mutation in their immunoglobulin (Ig) variable region heavy chain (Ig VH) genes compared to those with mutated Ig VH genes. Comparison between patients expressing VH1 (n = 9), VH3 (n = 40) and VH4 (n = 12) gene families, revealed down-regulation of WNT-3 and WNT-9A in VH3 positive patients. Our results indicate up-regulation of many members of the WNT gene family in CLL suggesting involvement of the Wnt canonical and/or noncanonical signaling pathways in CLL tumorigenesis.

Lymphoma in Adolescents and Young Adults

Non-Hodgkin (NHL) and Hodgkin (HL) lymphomas are represented prominently in the adolescent and young adult (AYA) population. These diseases represent 11% of total cancer diagnoses in children, 4% in those 40 years of age and older, and 13% in AYA (aged 15-39 years). Although age-adjusted incidence rates of NHL increase with age, the more aggressive lymphomas are seen more commonly in the younger population with a transition to low-grade, indolent subtypes as the population ages. Burkitt lymphoma, diffuse large B-cell lymphoma, lymphoblastic lymphoma, and anaplastic large cell lymphoma make up the most common subtypes in the AYA population, although within the subgroup age 30-39 years, follicular lymphoma becomes more prominent. As a result, much of the armamentarium in the treatment of aggressive NHL and HL in adults is based on data from pediatric clinical trials. There are obvious limitations to this approach. It is vital that we gain a more thorough understanding of the biology and therapeutic responsiveness of NHL and HL in the AYA population. Thus, we must leverage the large prospective and retrospective trials that have been completed to date and redirect our approaches to cancer care in this unique population. We review the epidemiological data on NHL and HL from the Surveillance, Epidemiology and End Results registries as a cornerstone for a comparative analysis of therapeutic outcomes available in this population.

The Role of the Microenvironment for CLL Proliferation and Survival: Gene Expression Profiling of Leukemic Cells Derived from Blood, Bone Marrow and Lymph Nodes Reveals the B-Cell Receptor and NF κB as Dominant Signaling Pathways

The host microenvironment is important for proliferation and survival of leukemic cells in chronic lymphocytic leukemia (CLL). Numerous molecules, signaling pathways and cell types have been reported to enhance CLL cell survival. To date, most reports on such interactions are derived from in-vitro studies, where each study focused on a specific ligand/receptor interaction or candidate pathway. Here, we adopted a more global approach to evaluate in-vivo effects of the microenvironment on leukemic cell biology. CLL cells from 15 patients were obtained on the same day from 3 different compartments: peripheral blood (PB), bone marrow (BM) and lymph node (LN), from which a single cell suspension was prepared. Tumor cells from all three compartments were purified by CD19 selection to purity >98%. Patients were assigned to prognostic subtypes based on immunoglobulin sequencing (Ig) and ZAP70 expression: 10 patients had the more progressive subtype (Ig-unmutated, ZAP70+) and 5 patients belonged to the more indolent subtype. Cells were analyzed for surface markers by flow cytometry and by gene expression profiling on Affymetrix HG U133 Plus 2.0 arrays. By flow cytometry, CLL cells in LN expressed higher levels of activation markers including CD69 and CD38 compared to CLL cells in PB (% CD19+/69+; 71 ±27 vs. 35 ±28, p<0.001 and % CD19+/CD38+; 33 ±28 vs. 20±19, p<0.001, respectively). The expression of activation markers in BM derived cells was less consistent and did not reach statistically significant differences. We therefore focused our analysis on a comparison between LN and PB derived cells. First, we confirmed that the expression of a diagnostic CLL gene expression signature established previously for PB derived cells (Klein et al, 2001) was equally present in leukemic cells derived from all three compartments. We then identified a set of about 275 genes that were differentially expressed between LN resident and circulating tumor cells, most of which were up-regulated (fold change >2, FDR <0.2). A large number of these genes encode proteins important for cell cycle control and proliferation: different cyclins, PCNA, Ki67, TOP2A and MYC. We also detected a significant increase in the expression of NF-κB target genes in LN resident tumor cells, including CD83, CD69, JunB, Cyclin D2, GADD45B, CCL3, CCL4 and others. Consistent with activation of the NF-κB pathway in LN, IκB-beta protein levels in tumor cells from LN were lower than levels in matching PB cells. Next we identified genes differentially expressed between CLL subtypes based on Ig-mutation status separately for each of the 3 compartments. Interestingly, these subtype identifying gene sets were only partially overlapping. In Ig-unmutated, ZAP70+ cells several genes were more strongly regulated by the microenvironment then in Ig-mutated, ZAP70 negative cells. Among these genes is LPL, which has been reported to distinguish the CLL subtypes, and other genes induced by B-cell receptor (BCR) signaling. Using in-vitro IgM activation, we show that these genes are indeed induced by BCR stimulation but not by CD40 ligation and that their induction is confined to ZAP70+ CLL cells. In conclusion: interactions between CLL cells and elements of the microenvironment in LN induce cell proliferation and NF-κB activation. The preferential upregulation of BCR regulated genes in ZAP70+ CLL demonstrates a more efficient in-vivo response of ZAP-70+ cells to BCR stimulation. Our results highlight the importance of NFκ κB and BCR signaling in CLL and provide a rationale to focus treatment approaches on these central pathways.

FDG-PET scans in patients with lymphoma

Lymphoma comprises a complex set of diseases, including Hodgkin and non-Hodgkin subtypes. An expected goal of management is chronic disease control over decades in most patients with indolent subtypes, and cure is a realistic target for aggressive histologies, including Hodgkin lymphoma. Making methods available to better assess prognosis and to more specifically tailor therapy toward individual subtypes is a priority. Positron emission tomography using the tracer (18)fluoro-2-deoxyglucose (FDG-PET) has become a valuable tool in the care of patients with lymphoma; it contributes information on staging and response assessment that has the potential to affect and improve patient care. This imaging modality is also being explored as an early response assessor, potentially allowing early prediction of an individual's response to a specific therapy. This information ultimately may lead to modifications of treatment to improve efficacy or reduce toxicity. Although FDG-PET offers valuable information, it is important to recognize its limitations as well as areas that require further exploration in order to optimally integrate its use into the clinical management of lymphoma patients.

Fc receptor‐like 1–5 molecules are similarly expressed in progressive and indolent clinical subtypes of B‐cell chronic lymphocytic leukemia

Fc receptor-like (FCRL) 1-5 molecules are exclusively expressed in B-cells and have recently been considered as potential targets for immunotherapy of B-cell malignancies. In this study, the expression pattern of FCRL1-5 molecules was investigated in Iranian patients with B-cell chronic lymphocytic leukemia (B-CLL). Our RT-PCR results have demonstrated that all FCRL molecules, except FCRL4, were expressed in the vast majority of the patients with B-CLL. However, comparison of the relative mRNA expression levels of FCRL between B-CLL (n = 86) and elderly normal subjects (n = 10) revealed significantly lower expression levels of FCRL1 (p < 0.0001), FCRL3 (p = 0.01) and FCRL4 (p = 0.002), but not FCRL2 or FCRL5, in cases with B-CLL. No significant differences were observed between the indolent and progressive subtypes of patients with B-CLL. Comparison between the mutated and unmutated subtypes revealed a significantly higher expression level of FCRL3 (p = 0.017) in patients with mutated CLL. Surface and intracytoplasmic expression of FCRL1, 2, 4 and 5 in leukemic cells of 12 patients by flow cytometry revealed similar results to those obtained by RT-PCR with a few exceptions. Thus, while FCRL4 was expressed in only 2 samples at intracytoplasmic level, FCRL1 and 2 were expressed in the majority of samples, both at surface and intracytoplasm. FCRL5 protein was also detected in 10 samples, but surface expression was confirmed in only 2. Analysis of B-cells from 5 normal subjects by flow cytometry revealed higher expression levels of FCRL molecules compared to CLL. Our results indicate differential expression of FCRL molecules in B-CLL and suggest the potential implication of FCRL1 and 2 for immunotherapeutic interventions.

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T‐cell lymphoma

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T-cell lymphomaAims:Aberrant histone acetylation has been associated with malignancy and histone deacetylase (HDAC) inhibitors are currently being investigated in numerous clinical trials. So far, the malignancy most sensitive to HDAC inhibitors has been cutaneous T-cell lymphoma (CTCL). The reason for this sensitivity is unclear and studies on HDAC expression and histone acetylation in CTCL are lacking. The aim of this study was to address this issue.Methods and results:The immunohistochemical expression of HDAC1, HDAC2, HDAC6, and acetylated H4 was examined in 73 CTCLs and the results related to histological subtypes and overall survival. HDAC1 was most abundantly expressed (P < 0.0001), followed by HDAC2; HDAC6 and H4 acetylation were equally expressed. HDAC2 (P = 0.001) and H4 acetylation (P = 0.03) were significantly more common in aggressive than indolent CTCL subtypes. In contrast, no differences were observed for HDAC1 and HDAC6. In a Cox analysis, elevated HDAC6 was the only parameter showing significant influence on survival (P = 0.04).Conclusions:High expression of HDAC2 and acetylated H4 is more common in aggressive than indolent CTCL. HDAC6 expression is associated with a favorable outcome independent of the subtype.

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T-cell lymphoma.

Aberrant histone acetylation has been associated with malignancy and histone deacetylase (HDAC) inhibitors are currently being investigated in numerous clinical trials. So far, the malignancy most sensitive to HDAC inhibitors has been cutaneous T-cell lymphoma (CTCL). The reason for this sensitivity is unclear and studies on HDAC expression and histone acetylation in CTCL are lacking. The aim of this study was to address this issue. The immunohistochemical expression of HDAC1, HDAC2, HDAC6, and acetylated H4 was examined in 73 CTCLs and the results related to histological subtypes and overall survival. HDAC1 was most abundantly expressed (P < 0.0001), followed by HDAC2; HDAC6 and H4 acetylation were equally expressed. HDAC2 (P = 0.001) and H4 acetylation (P = 0.03) were significantly more common in aggressive than indolent CTCL subtypes. In contrast, no differences were observed for HDAC1 and HDAC6. In a Cox analysis, elevated HDAC6 was the only parameter showing significant influence on survival (P = 0.04). High expression of HDAC2 and acetylated H4 is more common in aggressive than indolent CTCL. HDAC6 expression is associated with a favorable outcome independent of the subtype.

Pseudolymphoma evolving into diffuse large B-cell lymphoma

A 46-year-old man presented with a 1-year history of asymptomatic papules on the right arm, without an antecedent event. Initial clinical and histopathologic features were consistent with a pseudolymphoma without gene rearrangements, and the patient was treated with intralesional glucocorticoids. Four months later, the patient developed additional papules and plaques on the right arm, and, at this time, clinical and histopathologic features were most consistent with a T-cell-rich, large B-cell lymphoma, with monoclonal immunoglobulin light chain gene rearrangement. Systemic evaluation showed no evidence of extracutaneous involvement. The transformation of a pseudolymphoma into a large B-cell lymphoma is a rare event. This patient's subtype, diffuse large B-cell lymphoma-other, carries an intermediate prognosis when compared to the more aggressive leg subtype and more indolent folliculocentric subtype. Potential therapeutic options include local radiotherapy, chemotherapy, and rituximab.

Epidemiology, pathology and treatment of non-follicular indolent lymphomas

Non-follicular indolent subtypes of non-Hodgkin lymphoma (NHL), which include chronic lymphocytic leukemia, small lymphocytic lymphoma (SLL) and marginal zone lymphomas (MZL), are a diverse group of disorders with different presenting features, behaviour patterns and treatment outcomes. Current knowledge of these subtypes is largely based on retrospective analyses. A precise diagnosis can be difficult to achieve, and specific diagnostic criteria are needed to more precisely define some of the rarer indolent tumors, such as nodal and splenic MZLs. Although some subtypes of NHL have a prolonged indolent course, with a good prognosis (e.g. SLL), others (e.g. nodal and splenic MZLs) can rapidly evolve into more aggressive subtypes. In asymptomatic patients, treatment may be deferred until the disease progresses and the patient becomes symptomatic. Universally accepted therapeutic guidelines do not exist, however, and carefully designed, prospective clinical studies are needed to further assess optimal therapeutic approaches for these indolent NHLs.

Senile EBV‐associated B‐cell lymphoproliferative disorder of indolent clinical phenotype with recurrence as aggressive lymphoma

Senile EBV-associated B-cell lymphoproliferative disorder (LPD) was proposed as a new disease entity in 2003. This condition has a high incidence in elderly people without underlying immunodeficiencies, and is characterized by EBV-positive B-cell proliferation with a polymorphic composition. Histologically, the disease has two subtypes. The polymorphic LPD (PLPD) subtype has a preferable prognosis, whereas the large cell lymphoma (LCL) subtype involves aggressive disease progression. Reported herein is a case of senile EBV-BLPD with indolent clinical features and PLPD subtype in the initial phase that recurred as an aggressive lymphoma 3 years after the initial diagnosis. In the recurrent phase, Southern blotting confirmed monoclonal proliferation of large lymphoid B-cells. In both the initial and recurrent phases, polymerase chain reaction (PCR) yielded a single discrete band of a similar size due to an immunoglobulin heavy-chain gene rearrangement, indicating that the large lymphoid B-cells retained identical monoclonality throughout the histological progression and over the whole clinical course. These results suggest that the PLPD subtype is a histological finding in early phase senile EBV-BLPD and that the LCL subtype reflects the progressive phase of the disease.

Preliminary results from a phase II study of lenalidomide oral monotherapy in relapsed/refractory indolent non-Hodgkin lymphoma

8066 Background: Lenalidomide, an immunomodulatory drug, is approved in the US for treatment of relapsed/refractory multiple myeloma and myelodysplastic syndromes associated with a deletion 5q[31] cytogenetic abnormality. Lenalidomide also has activity in chronic lymphocytic leukemia and cutaneous T-cell lymphoma. This study was designed to assess the safety and efficacy of lenalidomide monotherapy in patients with relapsed/refractory indolent non-Hodgkin's lymphoma (NHL). Methods: Patients with relapsed/refractory indolent NHL with measurable disease after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Results: As of enrollment cut-off, 43 patients received drug and 27 were evaluable for response. The median age was 63 (43–82) and 12 were female. Histology was small lymphocytic lymphoma [SLL] (n=12), follicular center lymphoma grades 1,2 [FCL] (n=12) and nodal marginal B-cell lymphoma [NML] (n=3). Median time from diagnosis to lenalidomide was 4.3 (0.4- 24) years and median number of prior treatment regimens was 3 (1–17). Seven patients (26%) exhibited an objective response (2 complete responses (CR), 1 complete response unconfirmed (CRu) and 4 partial responses (PR)), 9 had stable disease (SD) for a tumor control rate (TCR) of 59% and 11 progressive disease (PD). Responses were produced in each of the indolent histologic subtypes studied: SLL (3/12), FCL (3/12) and NML (1/3). Since most responses develop at ≥ 4 months, additional responses may be seen in early SD patients with longer follow-up. Five patients (12%) exhibited Grade 4 neutropenia, and Grade 3 adverse events were neutropenia (16%) and thrombocytopenia (14%). Conclusion: Lenalidomide oral monotherapy is active with manageable side effects in relapsed/refractory indolent NHL. [Table: see text]

A unique case of IgD-only splenic marginal-zone lymphoma with mutated immunoglobulin genes: Ontogenetic implications

Splenic marginal zone lymphoma (SMZL) is a rare indolent lymphoma subtype which accounts for less than 1% of all non-Hodgkin's lymphomas. We here report a unique case of IgD-only SMZL with mutated immunoglobulin variable region genes and discuss possible ontogenetic derivation.

Serum Cytochrome C as a Tumor Marker in Leukemia and Lymphoma.

When cells become apoptotic, cytochrome c (Cyt c) is translocated from the mitochondria to the cytosol. It has been reported that Cyt c released to the cytosol is further released from the cells into the extracellular medium. Since tumor cells show an accelerated cell cycle with rapid cell growth accompanied by various grades of cell death including apoptosis, sera from patients with malignancies may contain increased levels of Cyt c. We thus investigated serum Cyt c as a tumor marker in hematological malignancies. Cyt c concentration was measured by our original electrochemiluminescence immunoassay. The measurement range of this assay was 5 to 3,000 ng/ml in serum. We confirmed that cell lines triggered by inducers such as anti-Fas/CD95 or TNF-related apoptosis-inducing ligand (TRAIL) released Cyt c into the culture medium within several hours. The serum Cyt c concentration in healthy adults showed a distribution from 14.6 to 36.1 ng/ml (median value: 25.1). Unexpectedly, there was no significant difference between healthy adults and patients with AML, CML, ALL, CLL, multiple myeloma (MM), non-Hodgkin Lymphoma (NHL) or adult T cell leukemia/lymphoma (ATLL), and the median values in these diseases were distributed between 19.7 and 42.4. Of note, however, there were some patients whose Cyt c concentrations were extremely high up to 2,533.2 ng/ml. Values over 50ng/ml were observed in three of the 10 patients with AML (30%), three of the 6 patients with ALL (50%), five of the 21 patients with ATLL (23.8%) and one of the 6 patients with NHL (16.7%). In contrast, there were no patients with CML, CLL or MM who showed values higher than 50 ng/ml. On subtype-analysis in ATLL, the five patients who showed more than 50 ng/ml all had aggressive subtypes, and none of the patients with indolent subtypes showed values higher than 50 ng/ml There was a significant positive correlation between Cyt c concentration and absolute ATLL cell counts in the peripheral blood. More interestingly, parallel analysis using serum and bone marrow specimens in AML and ALL indicated that bone marrow contained more than 10 times higher Cyt c than serum. These results indicate that certain rapidly growing tumor cells exhibit increased spontaneous apoptotic cell death, and serum and/or bone marrow Cyt c concentration can be a reliable marker to estimate the extent. Then, we examined serial serum Cyt c levels during chemotherapy to see whether they reflect the effect of chemotherapy. There was a clear correlation between serum Cyt c and the effect of chemotherapy; Cyt c increased several times soon after the start of chemotherapy, then returned to normal levels after completion. Although serum LDH activity also showed similar variation, the response of serum Cyt c was much quicker and sharper than that of LDH activity. In conclusion, serum Cyt c serves as a marker not only for spontaneous tumor cell death but also for monitoring chemotherapeutic response. Monitoring Cyt c provides new insight for understanding the pathophysiology of hematological malignancies.

Magnitude of Stromal Hemangiogenesis Correlates with Histologic Subtype of Non–Hodgkin's Lymphoma

Tumor stromal microenvironment promotes neoplastic growth and angiogenesis. We have previously shown that recruitment of marrow-derived vascular endothelial growth factor receptor-1(+) (VEGFR-1(+)) proangiogenic hematopoietic progenitors contributes instructively and structurally to neoangiogenesis in mouse models. Here, we investigated whether stromal incorporation of CD68(+) hemangiogenic cells and alpha-smooth muscle actin(+) (alpha-SMA(+)) stromal cells correlates with neoangiogenesis and progression in human non-Hodgkin's lymphoma subtypes. Spatial localizations of vascular and stromal cells expressing CD34, VEGFR-1, alpha-SMA, and CD68 were examined by immunohistochemistry in 42 cases of non-Hodgkin's lymphoma, including diffuse large B-cell lymphoma, Burkitt lymphoma, follicular lymphoma, and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and compared with benign follicular hyperplasia. Compared with indolent lymphomas, there was a profound increase in recruitment of CD68(+) cells and VEGFR-1(+) neovessels in aggressive subtypes (including those transformed from indolent subtypes), where CD68(+) cells were localized to the perivascular region of neovessels as well as the stromal compartment. The perivascular CD68(+) cells expressed VEGFR-1 and VEGF-A. In contrast, there was a diffuse increase in alpha-SMA incorporation throughout the stromal compartment of indolent subtype of CLL/SLL compared with the scant perivascular pattern in aggressive subtypes. Overall, there was no correlation between CD34(+) microvessel density and lymphoma histologic subtype. Heightened stromal hemangiogenesis as marked by infiltration of proangiogenic VEGFR-1(+)CD68(+)VEGF-A(+) cells and their paracrine cross-talk with neovasculature appears to be a distinct feature of aggressive lymphoma, providing novel targets for antiangiogenic therapy, whereas alpha-SMA(+) stromal vascular network may be differentially targeted in CLL/SLL.