Large-cell and immunoblastic lymphoma of the mediastinum: prognostic features and treatment outcome in 57 patients

Primary Mediastinal B-Cell Lymphoma: A 2021 Update on Genetics, Diagnosis, and Novel Therapeutics

Primary mediastinal large B-cell lymphoma (PMBCL) is an aggressive B-cell lymphoma arising from thymic B-cells having clinicopathologic features distinct from systemic diffuse large B-cell lymphoma (DLBCL). PMBCL comprises 2% to 4% of all non-Hodgkin lymphomas (NHL), 7% of DLBCL and seen predominantly in young females with a median age of 35 years at diagnosis. The annual incidence of PMBCL is 0.4 per million with a 5-year survival rate exceeding 70% with improving supportive care and genetic characterization of the disease. Pathogenesis involves dysregulation of Janus kinase-signal transducer and activator of transcription (JAK-STAT), nuclear factor-kB (NF-kB) pathways and amplification of the 9p24.1 region of chromosome 9. PMBCL patients have a prolonged life expectancy necessitating the need for treatment approaches that are based on maximizing cure with minimal long-term toxicity. Due to rarity and its recognition as a distinct entity, therapeutic decisions are guided by clinical presentation, clinician and center experience, and analysis of patients with PMBCL within DLBCL registries. Historically R-CHOP has been the usual first line treatment for PMBCL followed by involved site radiotherapy (ISRT), however clinical practice varies across centers with emerging consensus to avoid upfront RT by utilizing dose intense regimens (DA-EPOCH-R) in younger and fit patients. Prognosis of relapsed refractory PMBCL not responding to salvage chemotherapy is dismal, however there are many emerging options including Brentuximab Vedotin, immune check point inhibitors and chimeric antigen receptor T-cell therapy. In this article, we focus on the pathogenesis, current and evolving treatments, and provide recommendations for optimal management of patients with PMBCL.

Lymphoreticular malignancies in serous effusions: Cytomorphologic, flow cytometric and immunocytochemical analysis

INTRODUCTION

Involvement of body fluids by lymphoreticular malignancies (LRM) is rare and often associated with poor prognosis and decreased overall survival. The present study was conducted to analyze the characteristic cytomorphologic, flow cytometric and immunocytochemical features of LRMs in serous effusions.

MATERIALS AND METHODS

This was a three-year retrospective study. A total of 218 effusion samples, reported as involved by lymphoreticular malignancies, on cytology, were reviewed. All the cases wherein the cytological diagnosis was confirmed by flow cytometric (FCM) and/or immunocytochemical (ICC) studies were retrieved and studied in detail. FCM and/or ICC were performed in a total of 51/218(23.4%) samples, including 30 pleural (58.8%), 18 peritoneal (35.3%), and 3 pericardial fluid (5.9%) samples.

RESULTS

The cytomorphologic diagnoses included infiltration by non-Hodgkin lymphoma (NHL;n = 27), infiltration by LRM (n = 19), infiltration by chronic lymphocytic leukemia (CLL;n = 2), Hodgkin's lymphoma (HL;n = 1) and suggestive of infiltration by LRM (n = 2). FCM and/or ICC confirmed the diagnoses as infiltration by T-cell lymphoblastic lymphoma in 18; mature B-cell NHL in 10; Burkitt lymphoma in 7; diffuse large B-cell lymphoma in 4; follicular lymphoma, T- cell NHL and CLL in 2 samples each and hairy cell leukemia, plasmablastic lymphoma and HL in 1 sample each. 94.1% concordance was noted between the initial and final cytologic diagnosis.

CONCLUSIONS

Involvement of body fluids and effusions by LRMs, though rare, carries an immense prognostic significance and hence the prompt detection is crucial. Detection of these malignancies by cytologic examination of effusions is challenging yet potentially useful and the least invasive method available to establish an early diagnosis.

The characteristic computed tomography findings of pulmonary B-cell non-Hodgkin's lymphoma and their role in predicting patient survival

Background

To assess the value of characteristic computed tomography (CT) findings in predicting the survival of patients with pulmonary B-cell non-Hodgkin's lymphoma (NHL).

Methods

Eighty-four patients who were histopathologically confirmed with pulmonary B-cell NHL between 2004 and 2018 were retrospectively enrolled. All patients underwent chest CT scan at the time of initial diagnosis in our hospital. Characteristic CT findings and clinicopathological features of the patients were analyzed, and Cox regression models were used to determine the relationship of CT findings with overall survival (OS) and progression-free survival (PFS).

Results

Air bronchogram occurred more frequently in patients with early-stage disease, primary pulmonary lymphoma (PPL) and the indolent histological type of lymphoma than in patients with advanced-stage disease, secondary pulmonary lymphoma (SPL), and the aggressive histological type (all P<0.05). The halo sign was observed most in the SPL group (19/48, 40%; P=0.004), while the presence of cross-lobe sign was higher in patients with PPL (13/36, 36%; P=0.010). Pleural involvement and hilar/mediastinal lymphadenopathy were observed more in patients with SPL and the aggressive histological type (33/48 and 27/48; 31/46 and 26/46, respectively; all P<0.05). Survival analyses showed that the number of lung lesions, cross-lobe sign, and pleural involvement were independent prognostic factors for PFS, while the halo sign and pleural involvement were significantly correlated with OS (all P<0.05). More aggressive, advanced-stage cases and male patients showed worse outcomes.

Conclusions

The halo sign and pleural involvement are independent prognostic factors for OS, while the number of lung lesions, cross-lobe sign, and pleural involvement are correlated with PFS.

Treatment patterns, healthcare resource utilization, and costs of patients diagnosed with primary mediastinal B-cell lymphoma in the United States

AIMS

With the advent of ICD-10-CM codes for PMBCL on 10/01/2015, assessment of treatment patterns and healthcare burden among US patients is possible. This study sought to describe the real-world treatment patterns and economic outcomes of patients with PMBCL.

METHODS

Data from the Optum Clinformatics DataMart database was used (January 2013-March 2018). Patients with a first PMBCL ICD-10-CM diagnosis (with or without an antecedent ICD-10-CM diagnosis of DLBCL/other lymphoma, which may have been assigned before PMBCL confirmation) after 10/01/2015 (index date) and no ICD-9-CM diagnosis code for unspecified PMBCL/DLBCL were identified as incident patients. Those with PMBCL ICD-10-CM and unspecified ICD-9-CM diagnosis for PMBCL/DLBCL before 10/01/2015 (index date) were identified as prevalent patients. Patients were observed from the index date up to the earliest among death, end of data availability, or end of continuous health plan enrollment. An adapted algorithm was used to identify lines of therapy (LOT).

RESULTS

Among 118 incident and 30 prevalent PMBCL patients, 14% and 20% of patients received ≥2 LOTs, respectively. In incident patients, 48% received ≥1 LOT, 14% ≥2, and 4% ≥3 LOTs. Among prevalent patients, 63% received ≥1 LOT and 20% ≥2 LOTs. The most frequently recorded 1 L therapy was R-CHOP both among incident and prevalent patients. Mean total healthcare costs for incident and prevalent patients were $149,340 and $92,799 per patient per year, respectively, with higher costs ≤12 months ($187,241 and $167,553). Outpatient costs were the main driver (accounting for 60.5% and 64.6% for incident and prevalent patients, respectively).

LIMITATIONS

Potential underuse of ICD-10-CM codes shortly after discontinuation of ICD-9-CM codes in 01/2015; regimens identified for each LOT using the claims-based algorithm may not reflect the regimen administered.

CONCLUSION

The multiple LOTs necessary for a sizeable minority of patients and the high costs of care highlight the significant unmet needs of PMBCL patients.

Diagnostic role of cytology in serous effusions of patients with hematologic malignancies

BACKGROUND

We investigated serous effusions occurring during the course of an already known hematologic neoplasia or as a first manifestation of it. We correlated cytology results with flow cytometry results, when available. In the absence of flow cytometry, our correlation was based on clinical follow up information obtained retrospectively. We evaluated our results in relation to the data of the literature and we considered some new suggestions for the improvement of cytology service.

METHODS

Serous effusions in hematologic patients were retrieved from the files of the Department of Cytology, Laiko Hospital, for a period of 2 years. All patients had enrolled either a previous hematologic history, or a suspicious clinical and imaging status. Seventy-three serous effusions were included. Cytology reports consisting of morphology and immunocytochemistry assessment were correlated to flow cytometry results and, occasionally, to clinical follow-up.

RESULTS

In the group of patients with previous history, sensitivity was 82.76%, positive predictive value was 100%, specificity 100%, and negative predictive value was 58.33%. In the group of patients without previous history, sensitivity and positive predictive value were both 91%, whereas specificity and negative predictive value could not be estimated.

CONCLUSION

We provide evidence that the diagnostic accuracy of cytology with the adjunct of immunocytochemistry is high compared to flow cytometry for detecting hematologic malignancies. In order to improve clinical performance, it is suggested that a cytology triage of serous effusions in all patients with hematologic malignancy must be implemented.

How I treat primary mediastinal B-cell lymphoma

The World Health Organization now recognizes primary mediastinal B-cell lymphoma (PMBCL) as a unique clinical and biologic entity. PMBCL is distinct from other B-cell non-Hodgkin lymphoma subtypes and has features that overlap with classical Hodgkin lymphoma, including a peak incidence in the adolescent and young adult population, mediastinal presentation of disease, and molecular alterations in JAK2 and programmed death ligands. Because PMBCL is rare, there are few prospective clinical trials to guide therapy, resulting in no single standard of care. Given the long life expectancy of survivors of PMBCL, treatment approaches must balance maximizing cure while minimizing long-term toxicity. In this article, I review my approach to the treatment of PMBCL, incorporating data from adult and pediatric studies, as well as recent advances in our understanding of the molecular basis of PMBCL.

Outcomes of Relapsed and Refractory Primary Mediastinal (Thymic) Large B Cell Lymphoma Treated with Second-Line Therapy and Intent to Transplant

Primary mediastinal (thymic) large B cell lymphoma is a subtype of diffuse large B cell lymphoma with distinct clinical, molecular, and genetic features, many of which overlap with Hodgkin lymphoma. Increasingly, initial therapy for these patients has used dose-dense chemotherapy with or without radiation with excellent results. In patients with relapsed and primary refractory disease, outcomes of second-line therapy followed by consolidation with high-dose therapy and autologous stem cell transplantation remains largely undefined. We reviewed the outcomes of 60 transplant-eligible patients with relapsed or refractory primary mediastinal (thymic) large B cell lymphoma enrolled on sequential protocols with uniform second-line therapy with intent to consolidate with autologous stem cell transplant. The estimated 3-year overall and event-free survivals for all patients were 61% and 57%, respectively, and 68% and 65%, respectively, for patients proceeding to stem cell transplant. Multivariable analysis of risk factors before transplant revealed that an incomplete response to initial therapy, advanced Ann Arbor stage at disease progression, and failure to achieve a partial remission or better to second-line therapy to be independently associated with inferior event-free and overall survival. A risk score based on these variables was able to identify patients who are unlikely to respond to conventional second-line strategies. These results suggest that salvage chemoradiotherapy with intent of subsequent high-dose therapy and autologous stem cell transplant is successful in most patients with relapsed and refractory primary mediastinal (thymic) large B cell lymphoma. Alternative strategies are warranted for a significant subset of patients with high-risk disease who are unlikely to be cured with this strategy.

Indwelling Pleural Catheters for Patients with Hematologic Malignancies. A 14-Year, Single-Center Experience

RATIONALE

Placement of an indwelling pleural catheter is an established modality for symptom relief and pleurodesis in the treatment of malignant pleural effusion. Concerns remain regarding possible infectious complications, risk of hemorrhage, and the rate of pleurodesis with the use of pleural catheters in the treatment of hematologic malignancies.

OBJECTIVES

The goals of our study were: (1) to evaluate the safety and cumulative incidence of pleurodesis with indwelling pleural catheters for patients with hematologic malignancies, and (2) to evaluate overall survival of this cohort of patients with pleural effusions.

METHODS

We performed a retrospective review of 172 patients with a hematologic malignancy who underwent placement of an indwelling pleural catheter between September 1997 and August 2011 at the University of Texas MD Anderson Cancer Center in Houston, Texas. A competing risk model analysis was used for complications and pleurodesis. Analysis was based on each patient's first intrapleural catheter.

RESULTS

There were 172 patients with lymphoma (58%), acute (16%) or chronic leukemia (16%), or multiple myeloma (10%). The effusions were characterized as malignant (85.5%), infectious (4.1%), volume overload (4.7%), or therapy-related (4.7%). Chylothorax was found in 20.1%. Pleural biopsies were obtained from 13 patients. The cumulative incidence of all complications was 13.6%, and the cumulative incidence of all significant catheter-related complications was 9.5%. The incidence of empyema was 2.9%, and major bleeding (requiring transfusion or intervention) was 1.7%. Thirty-day procedure-associated mortality was 0.6%. The cumulative incidence of pleurodesis at 180 days was 50%, with a median time to pleurodesis of 81 days for the entire cohort.

CONCLUSIONS

Indwelling pleural catheters appear to be safe for patients with hematologic malignancies. Complications and the cumulative incidence of pleurodesis are comparable to those reported for patients with solid organ malignancies.

Primary mediastinal lymphomas, their morphological features and comparative evaluation

Background:

Primary mediastinal lymphoma is an uncommon tumor. Hodgkin's lymphoma (HL), primary mediastinal B-cell lymphoma (PMBCL), and T-lymphoblastic lymphoma are the most common primary mediastinal lymphomas. Key morphological and immunohistochemistry (IHC) features play a very crucial role in diagnosis as well as further categorization.

Materials and Methods:

In this study, the morphological spectrum and histological features of 32 cases of primary mediastinal lymphomas diagnosed over 5 years were studied and morphological and IHC features of PMBCL versus HL were compared. Features of PMBCL were also compared against a control group of systemic diffuse large B-cell lymphoma.

Results:

Although PMBCL and HL are known to show overlapping morphological features, it was observed that presence of clear cells and compartmentalizing fibrosis in PMBCL; and classical Reed–Sternberg cells and dense inflammatory background in HL are important morphological clues while evaluating the biopsies. PMBCL showed diffuse, strong and uniform CD20 positivity; whereas CD30 showed focal/patchy, weak to moderate and heterogeneous expression, wherever found positive. As against this, HL showed diffuse, strong and uniform CD30 positivity; and focal/patchy, weak to moderate and heterogeneous CD20 expression, if found positive. CD20, CD3, and CD30 were sufficient in most of the cases while diagnosing PMBCL and HL.

Conclusion:

This study emphasizes the critical examination of IHC markers. Only positive expression in neoplastic cells is not sufficient to make a diagnosis, equal importance should be given to percentage, intensity, pattern, and type of positivity. Apart from basic IHC described above; CD15, leukocyte common antigen and fascin played an important role in differentiating HL and PMBCL in select doubtful cases.

ACR Appropriateness Criteria® Diffuse Large B-Cell Lymphoma

The management of diffuse large B-cell lymphoma depends on the initial diagnosis including molecular and immunophenotypic characteristics, Ann Arbor staging, and International Prognostic Index (IPI score). Treatment approaches with different chemotherapy regimens used is discussed in detail. The role of radiation as a consolidation is discussed including: (1) the prerituximab randomized trials that challenged the role of radiation, (2) recent prospective studies (UNFOLDER/RICOVER-60), and (3) retrospective studies; the last 2 showed a potential benefit of radiation both for early and advanced stage. The document also discusses the role of positron emission tomography/computed tomography for predicting outcome and potentially guiding therapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Malignant effusions correlate with poorer prognosis in patients with diffuse large B-cell lymphoma

OBJECTIVES

Serous effusions are a common manifestation of diffuse large B-cell lymphoma (DLBCL). However, their prognostic significance is controversial.

METHODS

We searched for consecutive patients who had DLBCL with effusions from 1999 through 2007. Primary effusion lymphoma was excluded. The presence of tumor cells in effusions (malignant effusions) was determined by cytology supplemented by flow cytometry, cell blocks with special studies, polymerase chain reaction for clonality, or conventional cytogenetics.

RESULTS

Forty-one (18.4%) patients had effusions, with 24 (58.5%) developing at diagnosis and 17 (41.5%) during tumor course. Nineteen patients (46.0%) had malignant effusions, with six (31.6%) from local extension and 13 (68.4%) through wide dissemination. Interestingly, malignant effusion correlated with a high International Prognostic Index (IPI) score (r = 0.490, P = .002) and high tumor stage (r = 0.342, P = .031) and was a poor prognosticator (P < .001, log-rank test), even worse than stage IV disease (P = .036). In the multivariate analysis, malignant effusion (P = .056) and supportive care (P = .014) retained significance and were more powerful than IPI score and stage.

CONCLUSIONS

Patients who have DLBCL with lymphomatous effusions have a poor prognosis and should be treated as having stage IV disease. The analysis of effusions for tumor cells would be a useful addition to the routine workup.

Primary mediastinal lymphoma: diagnosis and treatment options

Primary mediastinal large B-cell lymphoma (PMBCL) is a unique B-cell lymphoma variant that arises from a putative thymic medulla B cell. It constitutes 2-4% of non-Hodgkin lymphomas and occurs most frequently in young females. PMBCL is characterized by a diffuse proliferation of medium-to-large B cells associated with sclerosis. Molecular analysis shows that PMBCL is a distinct entity compared to other types of diffuse large B-cell lymphomas. PMBCL is characterized by a locally invasive anterior mediastinal bulky mass. The combination of rituximab with CHOP/CHOP-like regimens followed by mediastinal radiation therapy (RT) is associated with a 5-year progression-free survival of 75-85%. However, the role of consolidation RT still remains uncertain. More intensive regimens, such as DA-EPOCH-R without mediastinal RT, have shown very promising results. The conclusive role of PET-CT scan requires prospective studies and there is hope that this may allow to de-escalate RT and accordingly yield reliable prognostic information.

Primary mediastinal large B-cell lymphoma: a single-center experience in Korea

BACKGROUND

Primary mediastinal large B-cell lymphoma (PMBL) is a distinct subtype of non-Hodgkin lymphoma, which has no consensus for its ideal treatment or prognosis.

METHODS

We reviewed the clinicopathologic features and clinical outcomes of 25 PMBL cases diagnosed at a single institution between 1993 and 2009 and compared them with 588 cases of non-mediastinal, diffuse large B-cell lymphoma (DLBCL, control group) diagnosed during the same period.

RESULTS

Thirteen (52.0%) PMBL patients had Ann Arbor stage III or IV disease, and 10 (40.0%) had B symptoms. Thirteen (52%) PMBL patients were classified as high-intermediate/high-risk according to the International Prognostic Index. There was a significant prevalence of young (median: 31 years; range, 15-78 years; P<0.001), female (68%; P=0.014) patients in the PMBL group compared to the control group (median: 56 years; range, 15-85 years; 43.2% female). Bulky disease and elevated levels of lactate dehydrogenase (LDH) were more frequent in the PMBL group (P<0.001 and P=0.003, respectively). Nineteen (76%) PBML patients achieved complete remission, and 18 were alive at the last follow-up (median: 43 months; range, 1-92 months). There was no difference in the 3-year, overall survival rate (72%, 95% confidence interval [CI]: 54.0-83.0 versus 70.1%, 95% CI, 109.0-126.0; P=0.686) between PMBL and control patients, respectively.

CONCLUSION

Compared to patients with non-mediastinal DLBCL, Korean patients with PMBL are predominantly young women with bulky disease and high LDH levels but with no significant difference in survival.

Pleural effusions in patients with Hodgkin lymphoma: clinical predictors and associations with outcome

Pleural effusions are common in Hodgkin lymphoma (HL). However, little is known about their prognostic significance. One hundred and ten patients with HL who presented to the University of Rochester from 1 January 2003 to 12 December 2010 were reviewed. Pleural effusions were evaluated on review of diagnostic-quality computed tomography (CT) scans. Pleural effusions were present in 26/110 patients: 1/7 (14%) stage I, 11/61 (18%) stage II, 3/18 (17%) stage III and 11/24 (46%) stage IV, and 25/91 (27%) patients had mediastinal involvement, 16/38 (42%) patients had extranodal involvement (any) and 5/14 (35%) patients had E lesions (direct extension to extranodal tissue). Unilateral and bilateral pleural effusions were equally prevalent. Survival analysis demonstrated decreased overall survival for patients with pleural effusions of borderline significance for stage I-IV (p = 0.055) but failed to show significance for patients with stage I-III (p = 0.115). Increasing stage, any extranodal involvement and bulky mediastinal disease were each predictive of pleural effusions. The presence of pleural effusion at presentation may be predictive of inferior survival for patients with Hodgkin lymphoma.

An aggressive form of non-Hodgkin's lymphoma with pleural and abdominal chylous effusions: A case report and review of the literature

Serous effusions, including pleural, abdominal and pericardial effusions, are complications of lymphoma. Among these types, pleural effusions are the most common to be observed. However, the involvement of the abdominal or pericardial cavity is rare. An impairment of the lymphatic drainage and direct infiltration have been identified to play significant roles in effusion formation. Multiple techniques, including cytological exams, immunochemistry and cytogenetics, have been applied in the clinic to access the qualities of the effusions and to attain a fast and precise diagnosis. Serous effusions are associated with a poor outcome for patients with lymphoma. The present study describes the case of a 28-year-old male patient with aggressive non-Hodgkin's lymphoma (NHL) involving pleural and abdominal chylous effusions.

Primary pancreatic lymphoma: a population-based analysis using the SEER program. Am J Clin Oncol. 2013;36:38-43. [PMID: 22134518 DOI: 10.1097/COC.0b013e3182354bbb]

BACKGROUND

Primary pancreatic lymphoma (PPL) is a rare disease, accounting for only 0.5% of all pancreatic masses. A paucity of literature exists on the epidemiology and outcomes of PPL. Here, we present a series of 523 cases of PPL obtained from the Surveillance, Epidemiology, and End Results database.

METHODS

Patients diagnosed with a PPL from 1973 to 2007 were identified. Data on patient and tumor characteristics as well as initial treatment with surgery or radiation were extracted. Survival rates were calculated using the Kaplan-Meier method. A multivariate analysis was performed to determine independent prognostic factors predicting mortality hazard ratios using Cox proportional hazards modeling.

RESULTS

Fifty-eight percent of patients identified were male. The median age range at diagnosis was 65 to 69 years. The most common histologic subtype in the present series was diffuse large B-cell lymphoma, which accounted for 56% of all patients. The 5-year overall survival for the group was 45%. Multivariate analysis suggests that age more than 60 years at diagnosis, race of "other" (compared with "white"), and marital status of single or widowed were predictive of increased all-cause mortality (P<0.05).

CONCLUSIONS

This represents the largest published series of patients with PPL. Age more than 60 years, female sex, and marital status of married were identified as independent prognostic factors predicting for decreased all-cause mortality.

Low expression of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein in non-Hodgkin lymphoma and significant correlations with lactic acid dehydrogenase and β2-microglobulin

Dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein (DC-SIGNR), a type II integral membrane protein and a member of the C-type lectins, has been reported to bind various strains of HIV-1, HIV-2, and simian immunodeficiency virus. Serum DC-SIGNR is not currently available for the detection of non-Hodgkin lymphoma (NHL). Using an enzyme-linked immunosorbent assay (ELISA), we assessed the serum levels of DC-SIGNR in 70 cancer patients and 100 healthy controls. Additionally, using immunohistochemistry, we determined the expression of DC-SIGNR in the lymph nodes. Using the ELISA, low serum levels of DC-SIGNR were detected in the patients (median, 4.513 ng·L(-1); range, 1.066-9.232 ng·L(-1); p = 0.0003). Serum concentrations of DC-SIGNR correlated significantly with age (p = 0.0077) and lactic acid dehydrogenase (p = 0.0046) and β2-microglobulin (p = 0.0491) levels. However, we found no statistically significant correlation between serum DC-SIGNR levels and clinical data such as sex, Ann Arbor stage, B symptoms, and histologic subtypes. Moreover, NHL patients with a lower level of serum DC-SIGNR expression in lymphatic endothelial cells also showed negative immunostaining levels. These results suggest that DC-SIGNR is a biological molecule that may be potentially useful in NHL clinical settings.

Primary mediastinal DLBCL: evolving biologic understanding and therapeutic strategies

Primary mediastinal diffuse large B-cell lymphoma is a quite rare clinicopathologic entity. Molecular analysis shows it to be distinct from other types of diffuse large B-cell lymphoma, and some retrospective analyses suggests that it may respond better to third-generation chemotherapy regimens than to the more commonly used CHOP. The addition of rituximab could reduce these differences; the role of consolidation with local radiotherapy, which is often used to treat residual mediastinal masses, remains. The real role of FDG-PET scanning requires prospective studies, and it is hoped that this may allow the de-escalation of radiation therapy accordingly to yield reliable prognostic information.

Randomized clinical trial to assess the efficacy of radiotherapy in primary mediastinal large B-lymphoma

PURPOSE

We developed a controlled clinical trial to assess the efficacy and toxicity of adjuvant-involved field radiotherapy (IFRT) in patients with primary mediastinal B-cell lymphoma that achieved complete response after the patients were treated with cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP-14).

METHODS AND MATERIALS

Between January 2001 and June 2004, 124 consecutive patients who were in complete remission after dose dense chemotherapy and rituximab administration (R-CHOP14) were randomly assigned to received IFRT (30 Gy). Sixty-three patients received IFR, and 61 patients did not (control group).

RESULTS

The study aimed to include 182 patients in each arm but was closed prematurely because in a security analysis (June 2004), progression and early relapse were more frequent in patients that did not received IFRT. Patients were followed until March 2009, at which point actuarial curves at 10 years showed that progression free-survival was 72% in patients who received IFR and 20% in the control group (p < 0.001), overall survival was 72% and 31%, respectively (p < 0.001). Acute toxicity was mild and well tolerated.

DISCUSSION

Adjuvant radiotherapy to sites of bulky disease was the only difference to have an improvement in outcome in our patients; the use of rituximab during induction did not improve complete response rates and did affect overall survival; patients who received rituximab but not IFRT had a worse prognosis.

CONCLUSIONS

The use of IFRT in patients with primary mediastinal B-cell lymphoma who achieved complete response remain as the best treatment available, even in patients that received rituximab during induction.

Primary mediastinal B-cell lymphoma treated with CHOP-like chemotherapy with or without rituximab: results of the Mabthera International Trial Group study

BACKGROUND

The aim of this subgroup analysis of the Mabthera International Trial Group study was to evaluate the impact of chemotherapy and rituximab in primary mediastinal B-cell lymphoma (PMBCL) in comparison to other diffuse large B-cell lymphoma (DLBCL).

METHODS

Patients were randomly assigned to six cycles of CHOP-like regimens with or without rituximab.

RESULTS

Of 824 patients enrolled, 87 had PMBCL and 627 other types of DLBCL. Rituximab increased the rates of complete remission (unconfirmed) in both PMBCL (from 54% to 80%, P = 0.015) and DLBCL (from 72% to 87%, P < 0.001). In PMBCL, rituximab virtually eliminated progressive disease (PD) (2.5% versus 24%, P < 0.001), whereas without rituximab, PD was more frequent in PMBCL than in DLBCL (24% versus 10%, P = 0.010). With a median observation time of 34 months, 3-year event-free survival (EFS) was improved by rituximab for PMBCL (78% versus 52%, P = 0.012) and for DLBCL (81% versus 61%, P < 0.001). Overall survival benefit was similar for DLBCL (93% versus 85%, P < 0.001) and PMBCL (89% versus 78%, P = 0.158).

CONCLUSION

In young patients with PMBCL (age-adjusted International Prognostic Index 0-1), rituximab added to six cycles of CHOP-like chemotherapy increases response rate and EFS to the same extent as other DLBCL. The combination of rituximab with CHOP chemotherapy is an effective treatment in PMBCL with good prognosis features.

Rituximab combined with MACOP-B or VACOP-B and radiation therapy in primary mediastinal large B-cell lymphoma: a retrospective study

BACKGROUND

Third-generation regimens (MACOP-B [methotrexate/leucovorin (LV)/doxorubicin/cyclophosphamide/vincristine/ prednisone/bleomycin] or VACOP-B [etoposide/LV/doxorubicin/cyclophosphamide/vincristine/prednisone/bleomycin]) in combination with local radiation therapy seem to improve lymphoma-free survival of primary mediastinal large B-cell lymphoma (PMLBCL). Recently, the superiority of R-CHOP (rituximab plus cyclophosphamide/doxorubicin/vincristine/ prednisone) over CHOP-like regimens has been demonstrated in elderly and younger patients with low-risk diffuse large B-cell lymphoma.

PATIENTS AND METHODS

Retrospectively, between February 2002 and July 2006, 45 previously untreated patients with PMLBCL were treated with a combination of a third-generation chemotherapy regimen (MACOP-B or VACOP-B), concurrent rituximab, and mediastinal radiation therapy.

RESULTS

Twenty-six (62%) patients achieved a complete response (CR), and 15 (36%) obtained a partial response after MACOP-B/VACOP-B plus rituximab. After radiation therapy, the CR rate was 80%. At a median follow-up of 28 months, among the 34 patients who obtained a CR, 3 relapsed after 16, 19, and 22 months, respectively. Projected overall survival was 80% at 5 years; the relapse-free survival (RFS) curve of the 34 patients who achieved CR was 88% at 5 years.

CONCLUSION

In this retrospective study, in patients with PMLBCL, combined-modality treatment using the MACOP-B/VACOP-B regimen plus rituximab induces a high remission rate, with patients having a > 80% chance of surviving relapse free at 5 years. In comparison with historical data on MACOP-B/VACOP-B without rituximab, there are no statistically significant differences in terms of CR and RFS rates.

Clinical features and treatment outcomes of adult B- and T-lymphoblastic lymphoma: results of multicentre analysis in Korea

We performed a retrospective multicentre analysis to study the clinical features and treatment outcomes of B-lymphoblastic lymphoma (B-LBL) and T-lymphoblastic lymphoma (T-LBL) in Asian adult patients, and identify risk factors that predict relapse and poor prognosis. Fifty-five newly diagnosed patients (45 T-LBL and 10 B-LBL) were analysed. All patients were treated with intensive chemotherapy regimens including VPDL (vincristine, prednisolone, daunorubicin, L-asparaginase), CALGB (Cancer and leukemia group B), and Stanford/Northern California Oncology Group (NCOG). There was no difference of clinical features between B- and T-LBL except the frequent site of involvement. The overall response rate including complete response (28/55, 50.9%) and partial response (18/55, 32.7%) was 83.6%. Among 46 responders, 22 patients relapsed leading to 20 deaths. Partial responders showed more frequent relapse (10/18, 55.6%) than complete responders (11/28, 39.2%). The median progression-free survival (PFS) was 17 months (95% confidence interval, 11.5-22.5), and the 2-year overall survival was 52 +/- 7% with a median follow-up of 50 months (range 8-152). Treatment outcome of T-LBL and B-LBL was not significantly different in terms of response and survival. The presence of pleural effusion was significantly prognostic for overall and PFS (p < 0.05). In conclusion, clinical features and treatment outcome of Asian adult LBL were comparable to previous results, and the prognosis is still poor despite intensive chemotherapy.

Primary mediastinal B-cell lymphoma: treatment and therapeutic targets

Primary mediastinal B-cell lymphoma (PMBCL) is a recognised subtype of diffuse large B-cell lymphoma according to the WHO classification that represents approximately 5% of aggressive lymphomas, and 2% of all cases of lymphomas. It presents with unique clinical, morphologic and immunophenotypic characteristics that define the disease. Retrospective studies have found that PMBCL patients have excellent survival rates with a distinct plateau and a trend to better outcome if treated with dose-intensified chemotherapy with MACOPB or VACOPB. In spite of the multiple molecular data known, generated on the pathogenesis of this tumour, treatment is still essentially based on a combination of chemo and immunotherapy. We take this opportunity for reviewing the recent biologic data provided by gene expression profiling of the tumour, for discussing new potential therapeutic targets.

Primary Mediastinal B-Cell Lymphoma

Primary mediastinal B-cell lymphoma is a discrete clinicopathologic entity. Molecular analysis reveals it to be distinct from other types of large B-cell lymphoma, and retrospective analysis suggests that it may respond better to multi-agent chemotherapy regimens than to the more commonly used CHOP. The addition of rituximab may mitigate such differences, and may also diminish the role of consolidation radiotherapy, which is often used to treat residual mediastinal masses. For the future the role of FDG-PET scanning requires prospective examination, and it is hoped that this may allow the de-escalation of treatment if it can be shown to yield reliable prognostic information. The relative rarity of this type of lymphoma necessitates international collaboration in clinical trials, with a prospective clinicopathologic study, IELSG 26, already underway.

Primary Mediastinal Large B-Cell Lymphoma: Results of Intensive Chemotherapy Regimens (MACOP-B/VACOP-B) Plus Involved Field Radiotherapy on 53 Patients. A Single Institution Experience

PURPOSE

The optimal therapy for primary mediastinal large B-cell lymphoma (PMLBCL) remains undefined. The superiority of intensive chemotherapy regimens (Methotrexate, Doxorubicin, Cyclophosphamide, Vincristine, Prednisone, Bleomycin [MACOP-B]/Etoposide, Doxorubicin, Cyclophosphamide, Vincristine, Prednisone, Bleomycin [VACOP-B]) over Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP)-like chemotherapy is upheld by some authors. The role of radiotherapy is still debated. In the absence of randomized trials, we report clinical findings and treatment response in 53 consecutive patients treated with intensive chemotherapy and mediastinal involved-field radiation therapy (IFRT).

METHODS AND MATERIAL

Fifty-three consecutive patients with PMLBCL were retrospectively analyzed. Planned treatment consisted of induction chemotherapy (I-CT; Prednisone, Methotrexate, Doxorubicin, Cyclophosphamide, Etoposide-Mechloroethamine, Vincristine, Procarbazine, Prednisone [ProMACE-MOPP] in the first 2 patients, MACOP-B in the next 11, and VACOP-B in the last 40) followed by IFRT. Planned treatment was concluded in 43 of 53 patients; in 10 patients, I-CT was not immediately followed by IFRT. Among these 10 patients, 6 received high-dose chemotherapy (HD-CT) followed by IFRT, 2 received HD-CT, and 2 received no further treatment.

RESULTS

After a median follow-up of 93.9 months (range, 6-195 months), 45 of 53 patients (84.9%) were alive without disease. Eight patients died: 7 of PMLBCL and 1 of toxicity during HD-CT. The 5-year disease-free survival (DFS) and overall survival rates were 93.42% and 86.6%, respectively. The response rates after I-CT were complete response (CR) in 20 (37.73%) and partial response (PR) in 30 (56.60%); 3 patients (5.66%) were considered nonresponders. Among patients in PR after chemotherapy, 92% obtained a CR after IFRT.

CONCLUSIONS

Our report confirms the efficacy of intensive chemotherapy plus mediastinal IFRT. IFRT plays a pivotal role in inducing CR in patients in PR after chemotherapy.

Cytomorphological and immunocytochemical study of non-Hodgkin's lymphoma in pleural effusion and ascitic fluid

INTRODUCTION

Non-Hodgkin's lymphoma (NHL) is often complicated by pleural effusion and ascites. The present study is an attempt to categorize the lymphomatous effusions according to the WHO classification, using archival material.

METHODS

May-Grünwald-Giemsa and Papanicolaou-stained smears of 31 lymphomatous effusion specimens were reviewed. Of these, detailed cytological assessment was done on 12 pleural effusions and ten ascitic fluid specimens from 22 patients using the WHO lymphoma classification system. Immunocytochemical studies were performed in 21 specimens.

RESULTS

Based on cytomorphological features, the 22 lymphomatous effusion specimens were categorized into lymphoplasmacytoid lymphoma (1), follicle centre cell (FCC) grade-1 (centrocytic) lymphoma (3), FCC grade-2 (centrocytic-centroblastic) lymphoma (3), FCC grade-3 (centroblastic) lymphoma (4), large cell immunoblastic lymphoma (4), lymphoblastic lymphoma (2), anaplastic large cell lymphoma (3) and miscellaneous types (2). Immunocytochemically, the lymphoma cells were T-cell (positive for CD3) and B-cell type (CD20 positive) in five and six cases respectively.

CONCLUSION

Cytological examination of pleural effusion and ascitic fluid samples, supported by immunocytochemical studies, may be useful for the classification of lymphomas under the WHO system.

Expression of TRAF1 and Nuclear c-Rel Distinguishes Primary Mediastinal Large Cell Lymphoma From Other Types of Diffuse Large B-cell Lymphoma

Primary mediastinal large B-cell lymphoma (PMLBCL) is a recently identified subtype of diffuse large B-cell lymphoma (DLBCL) that is difficult to distinguish from other types of DLBCL on the basis of histologic features alone. We recently identified a molecular signature of PMLBCL that is distinct from other forms of DLBCL but shares features with classical Hodgkin lymphoma. This signature includes activation of the nuclear factor kappaB (NFkappaB) signaling pathway, which in part, acts through nuclear translocation of c-Rel containing NFkappaB transcriptional complexes, and subsequent expression of NFkappaB target genes such as tumor necrosis factor receptor-associated factor-1 (TRAF1). Using standard immunohistochemical techniques, we examined 251 large B-cell lymphomas (78 cases of PMLBCL and 173 cases of other types of DLBCL) to determine whether the expression patterns of c-Rel and TRAF1 could reliably distinguish between PMLBCL and other types of DLBCL. Robust nuclear c-Rel was present in 31 of 48 (65%) cases of PMLBCL and 28 of 160 (18%) cases of DLBCL. In addition, cytoplasmic TRAF1 expression was seen in 48 of 78 (62%) cases of PMLBCL, but only 20 of 173 (12%) cases of DLBCL. Finally, the combined expression of nuclear c-Rel and TRAF1 was seen in 24 of 45 cases (53%) of PMLBCL, but in only 3 of 156 cases (2%) of other types of DLBCL. Thus, the combined nuclear localization of c-Rel and the cellular expression of TRAF1 is a highly specific (specificity=98%) means to distinguish PMLBCL from DLBCL that is readily applicable to routine surgical pathology practice.

Primary mediastinal B-cell lymphoma

Primary mediastinal B-cell lymphoma (PMBCL) is a sub-type of the heterogeneous diffuse large B-cell lymphoma category, and comprises approximately 5% of all non-Hodgkin's lymphomas (NHL). It was first recognized as a distinct clinico-pathologic entity 20 years ago, and recent work has further characterized specific molecular features. Gene expression profiling has suggested a partial overlap with nodular sclerosing Hodgkin lymphoma (HL), with which it shares some clinical features. The optimal management remains a matter of debate. There is uncertainty as to whether weekly alternating chemotherapy regimens may be more effective than CHOP, whether consolidation radiotherapy (RT) to the mediastinum is always required, whether PET scanning can be used to determine this, and whether the use of rituximab as part of initial therapy will change the answers to these questions. The International Extranodal Lymphoma Study Group (IELSG) 26 clinicopathologic study of PMBCL, which has recently opened, represents a first attempt to gather data prospectively on some of these issues.

Serous effusions in malignant lymphomas: A review

Serous effusions are a common complication of lymphomas. Although the frequency of pleural effusion is 20-30% in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), the involvement of peritoneal and pericardial cavities is uncommon. Among lymphoma subtypes, T-cell neoplasms, especially the lymphoblastic lymphomas, more frequently involve the serous fluids. The thoracic duct obstruction and impaired lymphatic drainage appear to be the primary mechanism for pathogenesis of pleural effusion in HD and direct pleural infiltration is the predominant cause in NHL. There is wide variation in rate of positive cytologic findings of NHL in pleural effusion (22.2-94.1%). Cytologic features of specific lymphoma subtypes such as lymphoblastic lymphoma, follicular center cell lymphoma, including Burkitt-type lymphoma, marginal zone lymphoma, MALT lymphoma, and anaplastic large-cell lymphoma, etc., have been described in the literature. The differential diagnostic problems of lymphomas in serous effusions include reactive lymphocytoses, early involvement by lymphomatous process, small round-cell tumors (SRCT), and presence of look-alike of Reed-Sternberg cells. To overcome these difficulties, various ancillary studies, including immunocytochemistry (ICC), morphometry, flow cytometry (FCM), and cytogenetics/molecular genetics (PCR, in-situ hybridization, and Southern blotting), have been performed on effusion specimens. ICC not only distinguishes lymphomas from reactive lymphocytoses and SRCTs, it significantly modifies the morphologic diagnosis to achieve a better classification of lymphomas. Combined morphology and immunophenotyping by FCM, has a sensitivity as well as specificity of 100%. Morphometry also distinguishes reactive lymphocytoses from malignant lymphoma with a high degree of sensitivity (>85%) and specificity (>95%). Limitations of individual ancillary techniques can be overcome by using multiple parameters. Although lymphomas rarely present as serous effusions without the involvement of other thoracic and extrathoracic sites, a small group of lymphomas called primary effusion lymphomas (PEL) exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. This body cavity based lymphoma (BCBL) is a distinct clinicopathologic entity and is found predominantly in AIDS patients with preexisting Kaposi sarcoma. In the absence of obstructive or infiltrative tumor mass, its pathogenesis has been attributed to stimulation by vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), leading to vascular leakage. Cytomorphologically, PEL is usually a large-cell lymphoma, which appears to bridge features of large-cell immunoblastic and anaplastic large-cell lymphoma (ALCL). Most of these cases comprise a unique subgroup of B-cell lymphoma, with features of both high-grade anaplastic and B-immunoblastic lymphoma, but T-cell and/or natural killer cell immunophenotypes are described. Its association with various viral DNAs has been studied in detail by molecular techniques. Pleural effusion due to lymphomas, either primary or otherwise, is considered as one of the factors adversely influencing overall survival. The presence of pleural effusion at the time of presentation is not only associated with extremely poor outcome of lymphomas, it is also a predictor of disease relapse after chemotherapy and decreased survival. When the patients of lymphomatous pleural effusions with and without mediastinal mass present in respiratory distress, thoracocentesis is the initial diagnostic and therapeutic choice in these patients. In such situations, cytology along with ancillary studies not only gives a quick diagnosis of lymphoma, but also offers prognostically significant information such as classification of lymphomas, its grade and immunophenotype, and presence/absence of viral DNAs and tumor lysis syndrome.

Tumors of the mediastinum

Tumors of the mediastinum represent a wide diversity of disease states. The location and composition of a mass is critical to narrowing the differential diagnosis. The most common causes of an anterior mediastinal mass include the following: thymoma; teratoma; thyroid disease; and lymphoma. Masses of the middle mediastinum are typically congenital cysts, including foregut and pericardial cysts, while those that arise in the posterior mediastinum are often neurogenic tumors. The clinical sequelae of mediastinal masses can range from being asymptomatic to producing symptoms of cough, chest pain, and dyspnea. This article will review the anatomy of the mediastinum as well as the different clinical, radiographic, and prognostic features, and therapeutic options of the most commonly encountered masses.

Primary mediastinal large B-cell lymphoma: optimal therapy and prognostic factor analysis in 141 consecutive patients treated at memorial Sloan Kettering from 1980 to 1999

Primary mediastinal large B-cell lymphoma (PMLBL) is a distinct clinicopathological entity with unclear prognostic factors and optimal treatment approach. To elucidate an optimal treatment and identify predictive factors, a retrospective analysis of 141 consecutive patients was undertaken. Patients received cyclophosphamide, hydroxydaunomycin, Oncovin, prednisone (CHOP)-like therapy, the non-Hodgkin lymphoma (NHL)-15 regimen or upfront autologous stem cell transplantation (ASCT) on Institutional Review Board approved trials or according to the institutional guidelines. Evaluation included lactate dehydrogenase, International Prognostic Index (IPI) assessment, computed tomography scan and gallium imaging. With a median follow-up of 10.9 years, event-free survival (EFS) and overall survival (OS) was 50% and 66% respectively. EFS/OS for CHOP/CHOP-like, NHL-15 and upfront ASCT was 34/51%, 60/84% and 60/78% respectively. CHOP/CHOP-like regimens had inferior EFS and OS versus NHL-15 or upfront ASCT (P < 0.001). A total of 23% of patients received radiotherapy. Multivariate analysis revealed the following outcome predictors: for EFS, greater than or equal to two extranodal sites and initial therapy received (NHL-15 or upfront ASCT); for OS, only initial therapy with NHL-15. We conclude: (i) dose-dense chemotherapy with NHL-15 may be superior to CHOP for PMLBL; (ii) The impact of consolidative radiotherapy requires randomised controlled trials; (iii) The age-adjusted IPI did not predict survival in this analysis; (iv) high-dose chemotherapy/ASCT should be reserved for upfront anthracycline-based therapy failure or in clinical trials for high-risk patients.

Primary Mediastinal Lymphoma

OBJECTIVE

To assess the characteristic features of the primary mediastinal lymphoma (PML) on CT and to test the relationship between CT findings and the likelihood of the 3 most common subtypes (Hodgkin lymphoma [HL], mediastinal diffuse large B-cell lymphoma [Med-DLBCL], and precursor T-cell lymphoblastic lymphoma [T-LBL]).

METHODS

Sixty-six consecutive patients with pathologically proven PML including 29 patients with HL, 21 with Med-DLBCL, and 16 with T-LBL underwent CT prior to therapy. CT scans were independently reviewed by 2 radiologists who were blinded to the pathologic diagnosis for the following considerations: pattern of involvement (i.e., morphologic features, mass size, and contrast enhancement pattern), and ancillary findings at other sites including neck, abdomen, and pelvis. Interobserver agreement was measured by Kappa statistics, and independent predictors were calculated using multiple logistic regression analysis for determining the likelihood of the subtypes based on CT.

RESULTS

Characteristic features of HL included irregular contour of the anterior mediastinal mass (20 of 29, 69%) and high prevalence of associated mediastinal lymphadenopathy (28 of 29, 97%). Characteristic features of Med-DLBCL included regular contour (14 of 21, 67%) and absence of cervical and abdominal lymphadenopathy (0 of 21). Characteristic features of T-LBL included regular contour (12 of 16, 75%) and high prevalence of cervical (9 of 16, 56%) and abdominal (6 of 16, 38%) lymphadenopathy and splenomegaly (11 of 16, 69%). CT findings independently associated with increased likelihood of HL were surface lobulation (P <0.01), the absence of vascular involvement (P <0.01), or pleural effusion (P <0.05). The presence of vascular involvement was associated with increased likelihood of Med-DLBCL (P <0.001). Furthermore, CT findings including the presence of cervical lymph nodes or inguinal lymph nodes (P <0.001), the presence of pericardial effusion (P <0.05), and the absence of surface lobulation (P <0.05) were significantly associated with the likelihood of T-LBL.

CONCLUSION

The various histologic subtypes of PML have characteristic manifestations in the neck, chest, and abdomen, which allow their distinction on CT.

Long-term follow-up after high-dose chemotherapy and autologous stem-cell transplantation for high-grade B-cell lymphoma suggests an improved outcome for high-risk patients with respect to the age-adjusted International Prognostic Index

BACKGROUND

To evaluate the long-term benefit from high-dose chemotherapy (HDCT) with autologous stem-cell transplantation (ASCT), as part of the initial treatment for patients with chemosensitive, high-grade B non-Hodgkin's lymphoma (hg B-NHL), stratified according to the age-adjusted International Prognostic Index (aaIPI).

PATIENTS AND METHODS

Eligible patients were 33 consecutive hg B-NHL patients responding to first-line chemotherapy and fulfilling at least one of the following criteria: stage III or IV, bulky disease, elevated lactate dehydrogenase or failure to achieve complete remission (CR). Twenty-two of 33 patients (67%) had two or three risk factors with respect to the aaIPI. All patients received HDCT with ASCT after a minimum of 6 weeks of VACOP-B standard therapy and VIP-E for mobilization.

RESULTS

After ASCT, 31 patients (94%) achieved CR. No treatment-related death occurred. The cumulative incidence of relapse at a medium follow-up of 10 years is 16% for 31 of 33 patients achieving CR. Twenty-five of 33 patients are in sustained CR with a disease-free survival of 76% [95% confidence interval (CI) 67% to 86%]. The overall survival at a median follow-up of 122 months (range 86-148) is 79% (95% CI 68% to 89%).

CONCLUSIONS

The results suggest that up-front HDCT with ASCT may improve long-term outcome in high-risk patients with chemotherapy-sensitive hg B-NHL when compared to historic populations treated solely with dose-intense chemotherapy. We observed that long-term survival of high-risk (two to three risk factors) patients is comparable to low-risk (zero to one risk factor) patients after HDCT and ASCT with a low incidence of late relapse.

Primary mediastinal large B-cell lymphoma: clinical study of a distinct clinical entity and treatment outcome in 20 patients: review of the literature

Primary mediastinal B-cell lymphoma (PMBCL) is a discrete subset of large B-cell lymphoma with unique clinicopathologic features. The question of optimal treatment emerges because it is an uncommon but not rare occurrence. A retrospective study was therefore conducted in a group of patients in Greece to evaluate the clinical features and treatment outcome in this disease. Twenty patients with PMBCL, with a median age of 42 years, treated at centers participating in the Hellenic Cooperative Oncology Group over the last 20 years, were reviewed. Thirteen (65%) had bulky disease at the time of presentation, 7 (35%) had superior vena cavae obstruction, and 15 (75%) had extranodal involvement. All received doxorubicin-containing chemotherapy, followed in 11 cases by mediastinal radiotherapy. With a median follow-up of 91 months, the median survival is 67.7 months. These data are consistent with those reported from other centers concerning the patient's characteristics, natural history, response pattern to chemoradiation therapy, and prognosis. Response to therapy proved of prognostic significance. A key question that remains is the prompt identification of patients who would benefit from innovative or more intensive therapies.

Primary Mediastinal Large B-Cell Lymphoma: A Single-Institution Clinical Study in Japan

Several clinicopathologic studies of primary mediastinal large B-cell lymphoma (Med-DLBCL) have been reported from Western countries; however, only a few series of at most 10 cases are available in Japan. To further clarify the Med-DLBCL occurring in Japan, we analyzed the clinical features of 28 patients with Med-DLBCL diagnoses who were treated at the National Cancer Center Hospital between 1982 and 2002. The median age was 37 years (range, 18-80 years). The ages of 16 male patients ranged widely from 18 to 80 years, whereas the 12 female patients appeared to show a single age peak at 20 to 40 years. Only 13 patients (46%) achieved a complete response with initial treatments, mostly by CHOP-like regimens (cyclophosphamide, doxorubicin, vincristine [Oncovin], and prednisolone) followed by radiotherapy. The estimated 3-year overall and failure-free survival rates were 32% and 33%, respectively, indicating the relatively unfavorable prognosis of the patients in our series. The following factors were found to be significantly associated with shortened survival prospects: age >60 years, serum lactate dehydrogenase level greater than normal, performance status >1, and presence of bulky mediastinal mass. In conclusion, the clinical features of Japanese patients with Med-DLBCL may be different from those with the disease in Western countries. Because this investigation was a single-institution study with a limited number of patients, however, multicenter confirmatory studies are needed.

Pleural Effusions in Hematologic Malignancies

Nearly all hematologic malignancies can occasionally present with or develop pleural effusions during the clinical course of disease. Among the most common disorders are Hodgkin and non-Hodgkin lymphomas, with a frequency of 20 to 30%, especially if mediastinal involvement is present. Acute and chronic leukemias, myelodysplastic syndromes, are rarely accompanied by pleural involvement. Furthermore, 10 to 30% of patients receiving bone marrow transplantation develop pleural effusions. In cases of hematologic pleural effusions, drug toxicity, underlying infectious, secondary malignant or rarely autoimmune causes should be carefully sought. In most cases, the pleural fluid responds to treatment of the primary disease, whereas resistant or relapsing cases may necessitate pleurodesis.

Primary mediastinal large B-cell lymphoma (PMLBCL): long-term results from a retrospective multicentre Italian experience in 138 patients treated with CHOP or MACOP-B/VACOP-B

The optimal treatment of primary mediastinal large B-cell lymphoma (PMLBCL) is still undefined. In the absence of randomised studies, we retrospectively analysed: (a) the effectiveness of two chemotherapy regimens (CHOP vs MACOP-B/VACOP-B) in complete remission (CR) achievement and event-free survival (EFS) and (b) the role of mediastinal involved-field radiotherapy (IF-RT) as consolidation. From 1982 to 1999, 138 consecutive patients affected by PMLBCL were treated in 13 Italian institutions with CHOP (43) or MACOP-B/VACOP-B (95). The two groups of patients were similar as regard to age, gender, presence of bulky mediastinal mass, pleural effusion, stage and international prognostic indexes category of risk. Overall, 75.5% of patients in CR received IF-RT as consolidation. Complete remission was 51.1% in the CHOP group and 80% in MACOP-B/VACOP-B (P<0.001). Relapse occurred in 22.7% of CHOP- and in 9.2% of MACOP-B/VACOP-B-treated patients (n.s.). Event-free patients were 39.5% in CHOP and 75.7% in the MACOP-B/VACOP-B group (P<0.001). The addition of IF-RT as consolidation improved the outcome, irrespectively of the type of chemotherapy (P=0.04). At a multivariate analysis, achievement of CR (P<0.0001) and type of CT (MACOP-B/VACOP-B) retained the significance for OS (P=0.008) and EFS (P=0.03). In our experience, MACOP-B/VACOP-B appears to positively influence OS and EFS in patients affected by PMLBCL, as compared to CHOP. Consolidation IF-RT on mediastinum further improves the outcome of CR patients.

Gallium-67 scintigraphy: a cornerstone in functional imaging of lymphoma

Until recently, gallium-67 scintigraphy (GS) has been the best available functional imaging modality for evaluating patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). The diagnostic accuracy of GS in detecting lymphoma is based on optimisation of the imaging protocol, knowledge of potential physiological and benign sites of (67)Ga uptake, and the Ga avidity characteristics of the individual lymphoma. As (67)Ga is a tumour viability agent, the role of GS is primarily at follow-up. A residual mass persisting on CT after treatment poses a common clinical dilemma: it may indicate the presence of viable lymphoma, which requires further treatment, or it can be benign, consisting of only fibrotic and necrotic tissues. GS can successfully differentiate between these conditions. Routine follow-up with GS may allow early diagnosis of recurrence and early institution of treatment. Reversion of a positive GS to a negative test, and the rapidity with which this occurs has a high predictive value for the outcome of the individual patient. Lymphoma showing a normal GS early during treatment has a better prognosis than lymphoma with persistence of pathological findings. Other tumour-seeking single-photon emitting agents, such as thallium-201, technetium-99m methoxyisobutylisonitrile and indium-111 octreotide, have been investigated in lymphoma, primarily as an alternative to GS in specific clinical settings, but are of limited value. The role of radioimmunoscintigraphy is gaining importance in conjunction with radioimmunotherapy. Fluorine-18 fluorodeoxyglucose (FDG) imaging of lymphoma using either dedicated or camera-based PET systems is gradually replacing GS for assessment of lymphoma. FDG overcomes some of the limitations of GS while sharing its tumour viability characteristics. The extensive clinical knowledge and experience accumulated over three decades with GS in lymphoma provides a solid background as well as a model for the assessment of new functional imaging techniques.

Efficacy of an early intensification treatment integrating chemotherapy, autologous stem cell transplantation and radiotherapy for poor risk primary mediastinal large B cell lymphoma with sclerosis

The aim of our study was to evaluate the impact of an early intensification programme including chemotherapy (CHT), autologous stem cell transplantation (ASCT) and radiation therapy (RT) in patients with primary mediastinal large B cell lymphoma (MLCL) with sclerosis presenting with adverse prognostic factors. Between 1993 and 1999, 19 patients with MLCL were referred to our institution. Four patients were classified as low risk according to the age-adjusted International Prognostic Index (AA-IPI). Fifteen (79%) were categorised in the high-intermediate or high risk group and were considered eligible for ASCT. Induction therapy consisted of VACOP-B (etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone and bleomycin) for 12 weeks. After induction therapy the four low risk patients achieved a complete remission (CR) and did not undergo ASCT. Of the 15 poor risk patients, five achieved CR, seven partial remission (PR), and three showed refractory disease (RD). All these patients received mobilising therapy consisting of high-dose cyclophosphamide. After peripheral stem cell (PSC) collection, to obtain a greater tumor mass reduction before transplantation, the seven patients in PR underwent further treatment with high-dose etoposide and those with RD received two cycles of DHAP (dexamethasone, cytarabine and cisplatin). At the time of ASCT, seven patients were in CR, six in PR and two had RD. After transplantation using BEAM as preparative regimen, all patients but one achieved a CR. Seven patients with minimal (<25%) residual mass at computed tomography scan received further mediastinal RT even if they had a negative Ga(67) scan. At a median follow-up of 35 months from transplantation the disease free survival is 93%. The outcome following this programme of early intensification in poor prognosis MLCL results in a high incidence of durable remissions even in patients with refractory disease.