Treatment of high-risk aggressive B-cell non-Hodgkin lymphomas with rituximab, intensive induction and high-dose consolidation: long-term analysis of the R-MegaCHOP-ESHAP-BEAM Trial

We have studied the feasibility and efficacy of intensified R-MegaCHOP-ESHAP-BEAM therapy in high-risk aggressive B-cell lymphomas. Altogether 105 patients (19-64 years) with diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBL) or follicular lymphoma grade 3 (FL3) with an age-adjusted International Prognostic Index of 2-3 were recruited. Treatment consisted of three cycles of high-dose R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), followed by three cycles of R-ESHAP (rituximab, etoposide, methylprednisolone, cytarabine, cisplatin) and high-dose consolidation with BEAM (BCNU, etoposide, cytarabine, melphalan) and autologous stem cell transplant. The 5-year progression-free survival (PFS) was 72% (DLBCL 60%, PMBL 89%) and overall survival (OS) was 74% (DLBCL 61%, PMBL 89%) after a median follow-up of 85 months. However, an independent prognostic factor was age only, with patients ≤ 45 years having 5-year PFS 90% and patients > 45 years having PFS 54%. PMBL had better prognosis than DLBCL/FL3 in patients > 45 years (PFS, 88% vs. 48%), but not in younger patients (PFS, 91% vs. 94%).

[Lymphomatoid granulomatosis - the past and present]

BACKGROUND

Lymphomatoid granulomatosis (LyG) is a rare multisystemic angiocentric and angiodestructive B lymphoproliferative disease that was first described by Liebow in 1972. Disease was then in the "gray zone" between vasculitis and lymphoproliferative disease. LyG is currently categorized as a primary B lymphoproliferative disease associated with Epstein-Barr (EB) virus according to the World Health Organization (WHO) classification of tumours. EPIDEMIOLOGY, CLINICAL COURSE AND TREATMENT: Lymphomatoid granulomatosis is a rare disease with unknown prevalence. It occurs more often in males (male : female ratio 2 : 1) between the 5th to 6th decade of life and is more frequent in Europe than in Asia. Lungs are typically the predominantly affected organ; the disease spreads predominantly by extralymphatic manner. Spleen and lymph nodes are affected at an advanced stage. The clinical features are often nonspecific. Dyspnea, cough, hemoptysis, chest pain are the most common features with/without B symptoms (fever, night sweats, weight loss) in the pulmonary involvement. The radiographic finding of the lung is very diverse, but when there are multiple bilateral nodular lesions with basal predominance in perilymphatic distribution, we should think of this disease, although LyG rarely occurs. The histopathologic examination of affected tissue (most commonly the lung) is necessary to confirm the diagnosis. The thoracoscopy is used mainly. When the pulmonary findings are without any response to antibiotics, the autoimmune cause and other granulomatous inflammations (tuberculosis, sarcoidosis, etc.) are excluded, this diagnostic performance is indicated. Prognosis is variable - from spontaneous remission to progressive disease, often with aggressive behavior. Median survival is 14 months from diagnosis and mortality rate is 60% in the first year - despite the treatment. Treatment strategy is chosen depending on the histological grade. The therapy is not yet standardized. Interferon α, rituximab, glucocorticoids, cyclophosphamide and combined immunochemotherapy have been used for the treatment. The disease may lead to pulmonary failure, fatal CNS (central nervous system) involvement and sometimes develops into progressive EB virus positive lymphoproliferative disorder.

CONCLUSION

Improvements in understanding of the biology of LyG, especially in determining the precise role of EB virus infection in its pathogenesis may lead to optimization of treatment strategies for this disease. Novel treatment modalities are urgently needed due to unfavourable prognosis. Adoptive immunotherapy appeals to be a promising approach.

The Hans algorithm failed to predict outcome in patients with diffuse large B-cell lymphoma treated with rituximab

Diffuse large B-cell lymphoma (DLBCL) consists of at least two biologically and pathogenetically different subtypes, the germinal centre B-cell (GCB) and the activated B cell type (ABC). It has been suggested that immunohistochemistry can discriminate these subtypes as well. The aim of this study was to verify the validity of the most commonly used Hans algorithm in patients with DLBCL treated with anthracycline- based chemotherapy with rituximab. Immunohistochemical staining using standard protocols was performed on formalin fixed paraffin-embedded tissues. CD20, CD5, CD23, BCL2, CD10, BCL6, MUM1 and Ki67 antibodies were applied. Out of 120 examined cases 52 patients were evaluated as GCB type and 68 patients as having non-GCB, out of a set of 99 patients treated with immunochemotherapy 45 patients with GCB and 54 patients with non-GCB DLBCL were identified. In this set of patients, there was no statistically significant difference neither in overall survival (OS) (HR 1.47 95% CI 0.51-2.63; p=0.45) nor in progression free survival (PFS) (HR 1.57, 95 % CI 0.76-3.22; p=0.731) between both groups.

[Histiocytic necrotizing lymphadenitis / Kikuchi-Fujimoto disease (HNL/K-F) and its differential diagnosis: analysis of 19 patients]

Histiocytic necrotizing lymphadenitis / Kikuchi-Fujimoto disease (HNL/K-F) is being recognized with an increasing frequency not only in the East Asia but also on the American continents and in the Europe. Still the diagnostics of HNL/K-F is not easy and difficulties with its proper classification persist. In a group of 19 patients diagnosed primarily or as consults at our department there were 12 woman and 7 men. An average age at diagnosis was 28 years, median 25 years. Cervical lymph nodes were involved in 18 patients. Bilateral lymphadenopathy was present in one patient, the remaining 17 were unilateral. Inguinal lymph node was affected in one patient. In one other patient there were enlarged retroperitoneal lymph nodes simultaneously with a cervical lymphadenopathy. The size of the lymph nodes varied between 5 mm to 32 mm. The subclassification showed the necrotizing type in 14 patients, in one there was a predominant xanthomatous tissue reaction around the necrotic areas (xanthomatous type), and in 4 patients the disease was recognized as the proliferative type without necrosis (in two with a variously intense apoptosis of the proliferating lymphocytes). Of 10 consult cases the tumor was primarily evaluated as B cell lymphoma not otherwise specified (1x), peripheral T cell lymphoma (1x), classical Hodgkin lymphoma of mixed cellularity (1x); two patients were submitted with a differential diagnosis between peripheral T cell lymphoma and HNL/K-F; in one diagnosis of probable EBV lymphadenitis and in one diagnosis HNL/K-F was made. There were no data submitted in the remaining three cases. The authors stress diagnostic features which should lead to the diagnosis of the disease and should prevent unnecessary oncological staging investigations and potential chemotherapy for a lymphoma. Among diagnostic features of HNL/K-F identification of the proliferating cells - CD8 activated lymphocytes with apoptotic decay prevail, there are frequent plasmacytoid monocytes and a striking reaction of macrophages which are CD68/myeloperoxidase positive. There are virtually no neutrophil granulocytes and there is a miminal participation of plasma cells. In case of necrotizing and xanthomatous type infectious causes are to be ruled out as well. In case we still need to distinguish HNL/K-F from a lymphoma PCR analysis of a rearrangement of the immunoreceptor gene in T cell population should be investigated.

[Histological diagnosis of Ph-negative myeloproliferative neoplasia. An overview]

A histological picture in pretreatment bone marrow trephine biopsy is an essential part of Ph-negative myeloproliferative neoplasm diagnosis according to WHO classification. Polycythaemia vera is histologically defined as a hypercellular trilinear myeloproliferation. Hypercellular haematopoiesis with granulocytic and megakaryocytic proliferation is typical for primary myelofibrosis. In essential thrombocythaemia the haematopoiesis is normocellular with proliferation of megakaryocytes only. The most important differential diagnostic features are morphology and distribution of megakaryocytes, and presence of fibrosis. In primary myelofibrosis there are typically ,dysplastic" megakaryocytes forming tight (dense) clusters, and variable extent of fibrosis, while mature megakaryocytes forming loose clusters and no fibrosis are found in essential thrombocythaemia. In reactive thrombocytosis and erythrocytosis the number of normally appearing megakaryocytes is not increased and they are not forming clusters. Prodromal (latent) phases of myeloproliferative neoplasms often unrecognized by recent WHO classification criteria are discussed as well as a differential diagnosis of myeloproliferative disorders associated with thrombocytosis.

[Diagnosis and treatment of BCR/ABL-negative myeloproliferative diseases--principles and rationale of CZEMP recommendations]

In 2009, the recommendations of the Czech Collaborative Group for Ph- Myeloproliferative Diseases (CZEMP) for diagnosis and treatment of BCR/ABL-negative myeloproliferative diseases (MPD), i.e., essential thrombocythemia (ET), polycythaemia vera (PV) and primary myelofibrosis (PMF) were updated and extended. The present article gives the rationale of the recommendations in full detail. The CZEMP diagnostic criteria for ET and PMF are based on histopathological (HP) findings, which must unconditionally be in line with the given clinical and laboratory characteristics of ET or of a certain stage of PMF, respectively. The platelet count is not decisive for diagnosis. In cases lacking an adequately taken and read HP finding, the Polycythemia Vera Study Group (PVSG) criteria are recommended. The diagnosis of typical PV is based on demonstration of the V617F mutation of the JAK2 gene along with a significant increase of red cell parameters. If these are close to borderline, the demonstration of increased total red cell mass (RCM) is required. In atypical cases lacking polyglobulia or elevated RCM, the HP picture of PV (in accordance with WHO description) plus JAK2 V617F mutation is satisfactory for diagnosis, or, in cases lacking JAK2 V617F mutation, the HP picture of PV along with polyglobulia (or increased RCM) is sufficient. The treatment principles of ET and other MPDs with thrombocythemia (MPD-T; i.e., the early stages of PMF and PV) are identical. The patients are stratified by their thrombotic risk (preceding thrombosis, another thrombophilic state, jAK2 mutation), presence of disease symptoms (mainly microcirculatory), platelet count and age. Only patients up to 65 years lacking the above mentioned risks with a platelet count < 1000 x 10(9)/l are considered as low-risk and do not demand cytoreducing therapy. The others are high-risk ones and have an indication for thromboreduction. In patients older than 65 years, the potentially leukemogenic drug hydroxyurea (HU) may be used. In the younger ones, the choice is between anagrelide (ANG) or interferon-alpha (IFN). In high-risk patients, the treatment goal is to maintain platelet counts below 400, and in low-risk ones, below 600 x 10(9)/l. In PV, polycythemia itself is another thrombotic risk factor. The condition is treated by bloodletting or erythrocytaphereses. If hematocrit levels < or =45 are not achieved, cytoreductive therapy using HU in patients over 65 years, or IFN in younger individuals is required. All patients with thrombocythemia in PV are high-risk and have an indication for cytoreduction. Acetylsalicylic acid is given to all patients with MPD-T with platelets < 1000 x 10(9)/l (at higher counts, hemorrhage is imminent), and to all individuals with PV, unless contraindication is present. In case of platelet count normalization, it may be withdrawn in cases of low-risk ET or PMF, not in JAK2+ PV. The treatment of advanced stages of PMF is symptomatic, with substitution of blood derivatives being the basis. The only curative treatment is allogeneic stem cell transplantation, which should not be indicated too early seeing to its risks, but also not too late--we must not allow transition into acute leukemia, which is heralded by blasts in the blood picture. The indication is the presence of any of the following criteria: values of hemoglobin < 10 g/dl, WBC < 4 x 10(9)/l and platelets < 100 x 10(9)/l, any percentage of blasts or > or = 10% immature granulocytes in the differential picture, >1 erythroblast per 100 cells--all at repeated examinations within at least a 2-month interval, and in addition, rapid progression of hepato-/splenomegaly, presence of general symptoms of the disease, portal hypertension and extensive swellings.

Distinguishing of primary mediastinal B-cell lymphoma and diffuse large B-cell lymphoma using real-time quantitative polymerase chain reaction

Primary mediastinal B-cell lymphoma (PMBL) seems to be reliably distinguished from diffuse large B-cell lymphoma (DLBCL) with microarray technology. We measured expression of Fcer2, Pdl2 and Blk genes using real-time quantitative polymerase chain reaction (RTqPCR) on formalin fixed, paraffin embedded material (FFPE) and suggested a formula to discriminate PMBL from DLBCL. For 39/82 included patients the diagnosis of PMBL was expected clinico-pathologically. Diagnosis of 10/39 and 2/43 of clinically considered PMBLs and DLBCLs, respectively, was not genetically confirmed. Compared to confirmed PMBLs, unconfirmed ones showed clinical features similar to DLBCLs, e.g. spleen infiltration (p=0,028) and decreased invasiveness in pericardium (p=0,045). They tended to have more common infradiaphragmatic involvement, less often tumor sclerosis or fluidothorax. There were no immunohistochemical differences between genetically confirmed and unconfirmed PMBLs. New approach of distinguishing PMBL and DLBCL is presented. It is based on expression of three genes in routinely available FFPE material using RTqPCR.

[Staging of non-Hodgkin's lymphoma--recommendations of the Czech Lymphoma Study Group]

BACKGROUNDS

The Ann Arbor system is typically used for the staging of Non-Hodgkin's lymphomas. This classification was nevertheless originally developed in the 1970s for Hodgkin's lymphoma, a disease usually confined to the lymph nodes with less frequent dissemination to extralymphatic organs/tissues and extremely rare primary extranodal involvement. Non-Hodgkin's lymphomas, however, are more often associated with extralymphatic involvement and primary extranodal lymphomas are relatively common (approximately 1/3 of cases). Therefore, the value of the Ann Arbor staging system appears to be limited in these cases. An analysis of data from centres participating within the Czech Lymphoma Study Group showed that staging of Non-Hodgkin's lymphomas with extranodal involvement is not uniform.

DESIGN

At the end of 2009, a draft for a Non-Hodgkin's lymphomas staging system was put forward for use by the lymphoma register of the Czech Lymphoma Study Group with special regard paid to the involvement of extralymphatic organs/tissues. This draft was further refined following comments from members of the Czech Lymphoma Study Group committee and the final form was accepted at the meeting of the Czech Lymphoma Study Group committee in January 2010.

RESULTS

A consensus was reached at the meeting of the Czech Lymphoma Study Group committee regarding the staging of various combinations of nodal and extranodal involvement. For the purpose of suitable staging and appropriate treatment intensity, extranodal organs were divided into "major"--liver, lungs, bones, mesothelium (pleura, peritoneum, pericardium) and soft tissues. All other organs were defined as "minor".

CONCLUSION

The Ann Arbor staging system is suitable for the staging of Non-Hodgkin's lymphomas with lymph node/lymphatic tissue involvement. As regards the extralymphatic spread of the disease or primary extranodal lymphomas, this classification should rather be adapted to practical needs. The validity of the updated classification system will be assessed in both prospective and retrospective Czech Lymphoma Study Group studies.

[Personalized medicine in haematooncology--the pathologist's perspective]

The concept of personalized medicine is not only an individualized therapeutic management of a patient; its prerequisite is an individualized approach to diagnosis. Most of oncological diagnoses and a many prognostic features are provided by a pathologists. The pathologist uses not only basic histological methods, but also a morphoproteomic and morphogenomic approaches. Integral part of a contemporary oncological diagnosis is a molecular investigation of a tumour, which can both prove the presence of molecules suitable for targeted therapy, and design a molecular "patient-specific" marker for minimal residual disease monitoring.

Analysis of risk factors: the rationale of the guidelines of the Czech Hematological Society for diagnosis and treatment of chronic myeloproliferative disorders with thrombocythemia

The rationale of the Czech Hematological Society guidelines for diagnosis and treatment of Philadelphia chromosome-negative myeloproliferative disorders with thrombocythemia (MPD-T) is reviewed. For diagnosis of MPD-T, the classification according to the World Health Organization or to the Rotterdam criteria is preferred because they distinguish true essential thrombocythemia from prefibrotic or early fibrotic idiopathic myelofibrosis and prepolycythemic polycythemia vera. The histopathology-based nosological distinction provided by these classifications yields valuable information on prognosis (including the risks of transition into secondary acute myeloid leukemia and myelofibrosis). Another serious complication in MPD-T is thrombosis (arterial or venous), the main risk factors of which are age, previous thrombosis, platelet counts 350 to 2,200 x 10 (9)/L (peak at approximately 900 x 10 (9)/L) and the presence of additional thrombophilic risk factors (hereditary thrombophilia, any hypercoagulable state, cardiovascular disease). The hemorrhagic risk starts increasing progressively at platelet counts > 1,000 x 10 (9)/L. Treatment should be stratified with respect to the thrombotic and hemorrhagic risks. In high-risk patients, thromboreductive therapy is warranted. All of the cytostatic drugs, including hydroxyurea, may be leukemogenic and should be given only to patients > 60 years old, whereas anagrelide or interferon alpha are preferred in younger individuals. In low-risk patients, antiaggregation therapy is sufficient, unless the platelet count exceeds 1,000 x 10 (9)/L, which is another indication for thromboreduction. Thrombopheresis is indicated in thrombocythemia > 2,000 x 10 (9)/L.

Prognostic relevance of the FAB morphological criteria in chronic lymphocytic leukemia: correlations with IgVH gene mutational status and other prognostic markers

Morphological examination is the routine first step in the diagnosis of hematological malignancies, including chronic lymphocytic leukemia (CLL). Atypical cell morphology according to the FAB criteria is known to herald disease progression. Several years ago, it was proposed that FAB morphology at diagnosis had a considerable prognostic impact. However, this proposal has not been widely adopted in practice. Thus we questioned the prognostic value of the morphological examination, which was performed retrospectively in 88 patients out of our 110 institutional registry patients (70 males and 40 females, median age 57 yrs) with CLL at diagnosis. We related the results to the more modern prognostic markers. Atypical FAB morphology was shown to correlate with IgVH gene mutation status, trisomy of chromosome 12 and deletion of 17p detected either by conventional G-banding or by fluorescence in situ hybridization (FISH) analysis. The correlation of FAB morphology with CD38 antigen expression or with the histopathological pattern of bone marrow infiltration was not significant. Overall survival (OS) data were available for 84 morphologically examined patients. The patients with atypical morphology (64 patients) had a significantly shorter OS (103 months) than the 20 patients presenting with typical CLL morphology (237 months; p=0.03). Only the mutation status of IgVH genes correlated more closely with OS (p=0.002). Of note, there was no leukemia-related death within "unmutated" cases who had typical FAB morphology (p=0.14), and vice versa, the mutation status had a significant prognostic impact within the morphologically atypical cases (p=0.01). Thus FAB morphology and the mutation status may yield complementary prognostic information. OS was affected both by the presence of cytogenetic aberrations (p=0.03) - most adversely by deletions of 17p and 11q, and by CD38 expression (p=0.003). We conclude that careful examination of peripheral blood smears according to FAB is a simple, cheap and valuable tool in the first-line assessment of prognosis of CLL patients and should not be overlooked even in 3rd millennium when more sophisticated prognostic markers are at hand. This ought to be confirmed in larger prospective studies with multivariate analysis of data.

[Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis). Case study and a literature review]

Kikuchi-Fujimoto disease is a rare feverish disease characterised by lymphadenopathy, the most frequently cervical, exanthem, arthralgias and arthritis. It affects especially young women. Patients have high erythrocyte sedimentation rate (ES) and leucopenia, antibodies are missing. Course of the disease is usually very benign and can subside spontaneously. However, clinical picture is usually very dramatic and can suggest infectious, autoimmune or malign systemic disease; also association with some of autoimmune diseases was described. Its occurrence is sporadic in all the world, the most of cases were seen in Asia, in the Czech Republic it has not been yet described. Therapy consists in antibiotics administration followed with corticoid therapy and usually can restore patients to perfect health. However, exacerbations have also been described. We describe a case of a 60 year old man, a past top sportsman, who has never been seriously ill except sport traumas and prosthesis implantation for coxarthritis reasons. The last two years he has suffered from exanthem and leucopenia of an unclear origin. In May 2002 he become feverish and arthritis, lymphadenopathy, splenomegalia and exanthem progression, high ES rate and high serum level of C-reactive protein (CRP) appeared in him. His condition was first evaluated as septic condition (founded staphylococci in two blood cultures), however, cause of potential sepsis has not been identified. The patient was treated with antibiotics with improvement of his total health condition after second treatment regiment. A neck node biopsy was done because of suspicion on lymphoprolipherative disease and histiocytic necrotizing lymphadenitis of Kikuchi type was found. Autoantibodies assessment was completely negative. After antibiotic and corticoid therapies his clinical condition quite quickly standardized and ES rate and serum CPR level decreased. 4 month after lowering the dose of prednisolon a temporary exacerbation of the disease appeared and again disappeared after increasing the dose of corticoid.

Multiple granular cell tumour

Myoblastic myoma was first described in 1926. Immunohistochemical methods have proven the neuroectodermal origin of this tumour. It most frequently affects individuals between 30 and 60 years of age, with a significant female predominance. In most cases it is a benign solitary tumour, with multiple lesions found in 25% of cases. The malignant variant of the tumour is diagnosed in less than 3% of cases. This case report of a 30-year-old woman describes the appearance of a solid resistance between her breasts following delivery of her child, with similar findings on the neck and wrists. Histopathological examination confirmed the presence of a benign variant of myoblastic myoma.

[New aspects of MALT lymphomas of the stomach]

The knowledge about MALT lymphomas has dramatically changed in the last few years. The genesis of MALT lymphomas has become clearer, and new tools in modern diagnostics are available. This article, as a concise review, summarises the latest data and the clinical and morphological characteristics with the aspect of routine diagnostics. The characteristic translocation t(11;18) and its chimeric transcript API2-MALT1 with antiapoptotic function is emphasised.

Mantle cell lymphoma: improved diagnostics using a combined approach of immunohistochemistry and identification of t(11;14)(q13;q32) by polymerase chain reaction and fluorescence in situ hybridization

INTRODUCTION

Mantle cell lymphoma (MCL) is a clinicopathological entity characterized by an aggressive clinical course, morphological features, and overexpression of cyclin D1 due to juxtaposition of the bcl-1 locus (and CCND1 gene coding for the cyclin D1) to the IgH gene. This phenomenon is caused by t(11;14)(q13;q32). The morphological diagnosis of MCL may pose difficulties. Ancillary methods are available to support the diagnosis.

PATIENTS AND METHODS

We studied a group of 32 patients with MCL; 24 men and 8 women. The median age at the diagnosis was 64 years. We characterized the investigated group by histology, and to analyze the immunohistochemical (IHC) profile we used a panel of antibodies including anti-cyclin D1. Polymerase chain reaction (PCR) was used to detect the rearrangement of bcl-1/IgH in 26 cases (in 11 patients, the DNA was isolated from frozen tissues or from nucleated cells of bone-marrow aspirate or peripheral blood, in 15 patients we utilized paraffin-embedded material). Dual color fluorescence in situ hybridization (FISH) on interphase nuclei detecting the t(11;14)(q13;q32) was applied in all 32 cases.

RESULTS

Cyclin D1 IHC was positive in 29 of 30 cases tested (97%). In six, the result was weak and difficult to rely on to support the diagnosis. PCR revealed the fusion gene in 14 of the 26 cases (54%). The best yield was obtained from fresh and frozen samples (8 of 11 positive). Using FISH, we identified the translocation in all 32 patients, the findings being easily interpretable in 29 patients. In three cases, the intensity of red and green signals was weaker and difficult to read though the co-hybridized signals were identified. The classical pattern of the translocation was observed in 26 patients, while in 3 we found variant patterns suggesting a loss of the V segment of the IgH gene (2x) and a shift in the breakpoint region at chromosome 11 (1x).

CONCLUSION

The diagnosis of MCL should be supported by a complex laboratory approach. Interphase FISH seems a useful complementary method to morphology and IHC. It is applicable to various tissues and cells prepared as tissue imprints or histological sections.

[Large-cell diffuse B-cell lymphoma: heterogenous origin and prognosis from the aspect of modern diagnosis]

BACKGROUND

Diffuse large B-cell lymphomas represent a heterogeneous group of tumors with a different origin, morphological findings and a variable clinical prognosis. These tumors have been recently classified into two prognostically relevant subgroups differing in the gene expression. The key genes suitable for routine diagnostics of DLBCL have not been yet identified. The aim of this work was to study changes and expression of several genes and proteins participating in the genesis of DLBCL.

METHODS AND RESULTS

We analysed a group of 31 patients with diffuse large B-cell lymphomas. Basic clinical data including follow-up of the patients were available. Tumors were examined by a panel of immunohistochemical reactions with antibodies against CD20, CD79a, BCL-2, BCL-6, CD10, Ki-67 and TP53. FISH was used to detect a translocation t(14;18)(q32;q21) and/or a break in BCL6 region (3q27) suggestive of a translocation with a variable translocation partner t(3;?). PCR was utilized to detect the translocation t(14;18) and a clonal rearrangement of heavy and/or kappa chain of the immunoglobin genes.

CONCLUSIONS

The expression of BCL-2 protein appeared to correlate with a higher mortality rate. The expression of other proteins examined in the study did not correspond significantly with the clinical development of the disease. Tumors with follicular lymphoma as a component had significantly higher mortality rate than the tumors developing de novo. Moreover, higher mortality was evident in cases with higher values of the International Prognostic Index (IPI).

[Correlation of results of flow cytometry and morphologic findings in the diagnosis of malignant B-cell lymphoma]

BACKGROUND

Immunophenotyping of malignant lymphomas becomes necessary for the correct classification, for the design of therapy and for prognosis projection (WHO). Although the spectrum of classic immunohistochemical (IHC) examinations in paraffin embedded or frozen sections has recently considerably extended, IHC should preferably be combined with flow cytometry. The main advantage of flow cytometry is a synchronous application of two or more antibodies marked with various fluorochromes in one sample. The method is limited by utilizing native material only.

METHODS AND RESULTS

The flow cytometry combined with histological and IHC investigations were used in diagnosis of primary non-Hodgkin's lymphomas of B-cell origin (B-NHL) and for bone marrow staging or restaging. We studied 90 patients with confirmed or suspected B-NHL and we found a good correlation in 89% of samples of primary lymphomas and in 85% of bone marrow samples when IHC and flow cytometry results were compared. The overall efficacy of the flow cytometry determination in lymphoma infiltration of the samples was 89%.

CONCLUSIONS

Immunophenotyping utilizing flow cytometry contributes to diagnosis and classification of B-cell lymphomas in the significant proportion of investigated patients. In some cases it is even unnecessary to employ IHC examination of tissue sections. The method is especially suitable for determination of monoclonal populations of B-cells by detection of cell surface markers because it is more specific and sensitive than IHC. The immunophenotyping by flow cytometry as an auxiliary method and in correlation with morphological findings it can make the diagnosis of B-cell lymphomas faster and more specific.

[Comparison of proliferative activity in malignant lymphomas determined by immunohistologic methods with various antibodies]

Proliferation Index (PI) was evaluated in a group of 48 malignant lymphomas. Comparison of 3 antibodies showed that DAKO-EPOS Anti-PCNA/HRP and MIB-1 (Immunotech) suite to routine PI evaluation. Low figures of PI were obtained when using DAKO-EPOS Anti-Ki-67/HRP which did not even discriminate between prognostic groups of malignant lymphomas.