[Epstein-Barr virus genome positive lymphoepithelioma-like carcinoma of the stomach]. / A gyomor Epstein-Barr-vírusgenom pozitív lymphoepitheliomaszerú carcinomája.

EBV is associated with a high number of tumours and non-tumourous conditions. The rare lymphoepithelioma like carcinoma of the stomach,--just as similar tumours of foregut origin (thymus, lung, salivary gland)--are frequently EBV genom positive with the expression of only a few genes (EBV nuclear antigen 1, EBV encoded ribonucleoproteins/EBER/, latency I). On the basis of the clinicopathological analysis of two cases and literature data the authors point out the male predominance and the relatively favourable prognosis of the patients, furthermore the frequent cardial-subcardial localization of these tumours. Since the frequent non-lymphoepithelioma like stomach tumours,--adenocarcinomas,--show EBV genom positivity in about 1% of the cases, it is concluded that the characteristic lymphoepithelioma like histological pattern is not a sine qua non condition of EBV genom positivity. It may also be assumed, that the CD8 and TIA 1 cytotoxic lymphocytes are not virus but tumour cell specific, however not efficient, perhaps not activated. The low level of apoptotic tumour cells supports this assumption. In one of the cases a double tumour, a genom positive lymphoepithelioma like carcinoma and a genom negative adenocarcinoma, adjacent to each other was seen which speaks in favour of common carcinogenetic factors and shows that microscopic neighbourhood is not a necessary condition in viral association. The origin of the possible oncogenic effect of EBV in the absence of the transforming gene products latent membrane protein 1 and EBNA 2 in genom positive stomach carcinomas is uncertain. The significance of the presence in both cases of CD 5+ tumour cells is not clear, the study of further cases is indicated.

[Detection of minimal residual diseases in B-cell tumors using PCR specific for the immunoglobulin heavy chain gene]. / A minimális reziduális betegség kimutatása B-sejtes tumorok esetében az immunglobulin nehézlánc génre specifikus polimeráz láncreakció segítségével.

In B-cell non-Hodgkin's lymphomas (NHL), clonal rearrangement of the immunoglobulin heavy chain (IgH) gene provides a useful marker for the detection of minimal residual disease (MRD) after treatment. To explore clinical usefulness of polymerase chain reaction (PCR) analysis of clonal IgH gene rearrangement in the detection of MRD a follow up study of 10 patients with B-cell NHL have been performed. At the time of diagnosis, tumor DNAs were PCR-amplified using sense primer specific for the heavy chain variable region (VH) and antisense primer specific for the heavy chain joining region (JH) of the IgH gene. The clonal rearrangement of IgH gene detected by PCR was used as clonal marker to determine MRD after treatment. In three cases, where clinical remission was not achieved, clonal IgH gene rearrangement was detected after the treatment. In seven cases, clinical remission was achieved after induction therapy but the PCR analysis revealed clonal IgH gene rearrangement in three of the cases. In all of the three cases, where MRD was detected by PCR, clinical relapse developed after 7-28 months of the therapy. In all cases that have relapsed, the IgH gene rearrangement was identical at the time of initial diagnosis and at the relapse. This study demonstrates that PCR analysis of clonal IgH gene rearrangement is a useful method to monitor and detect MRD before clinical relapse.

Immunoglobulin V(H) gene mutational analysis suggests that blastic variant of mantle cell lymphoma derives from different stages of B-cell maturation.

To characterise the nature of the cellular origin of the blastic variant of mantle cell lymphoma (MCL-BV), we analysed the immunoglobulin (Ig) heavy chain variable region (V(H)) genes in four cases of MCL-BV. The rearranged V(H)-D J(H) genes were PCR-amplified, cloned and sequenced. In one case, the comparison of the rearranged V(H) gene sequence to known germline V(H) gene templates showed no somatic mutations suggesting a pre-germinal centre B-cell origin for tumour cells. In the other three cases, the V(H) gene sequences showed varied number of point mutations relative to the putative germline V(H) gene sequences but the point mutations were not associated with intraclonal diversification. In one of the mutated cases, the distribution and type of the mutations indicated that tumour cells had been selected by an antigen. Since somatically mutated Ig genes are expressed by B-cells that have reached a germinal centre/post-germinal centre stage of development, these findings suggest that the MCL-BV cell of origin may also be a germinal centre or a post-germinal centre B-cell. Taken together, our findings suggest that the development of MCL-BC may not be restricted to one stage of B-cell differentiation and that they may represent transformants of B-cells at different stages of ontogeny.

[Analysis of T-cell receptor gamma-gene rearrangement in lymphoproliferative disorders using polymerase chain reaction]. / A T-sejt receptor gamma-génátrendezödés vizsgálata lymphoproliferativ kórképekben polimeráz láncreakció segítségével.

T-cell non-Hodgkin's lymphomas (NHL) exhibit a clonal T-cell receptor (TCR) gamma gene rearrangement as a result of sequential assembly of their variable (V gamma) and joining (J gamma) region segments. The analysis of the TCR gamma gene rearrangements may help to differentiate reactive lymphoproliferations from T-cell NHLs. The aim of this study was to reveal the usefulness of polymerase chain reaction (PCR) analysis of the TCR gamma gene rearrangement in the diagnosis of T-cell NHLs using native and formol-paraffin embedded tissues. The PCR amplification of the TCR gamma gene was performed by the V gamma specific sense and J gamma specific antisense primer pairs. The PCR products were evaluated by polyacrilamide gel electrophoresis containing ethidium bromide. The PCR analysis of the TCR gamma gene rearrangements has been performed in 95 lymphoproliferative disorders. The PCR analysis of the TCR gamma gene showed clonal gene rearrangement in 22 cases out of the 39 T-cell NHLs and in one case out of the 12 O-cell anaplastic large cell lymphoma but no clonal rearrangements were detected in any of the 15 reactive lymphoproliferations or 13 B-cell NHLs. Thus, clonal TCR gamma gene rearrangements was detected by PCR in 58.2% of T-cell NHLs but no clonal TCR gamma gene rearrangements were shown in any of reactive lymphoproliferations of B-cell NHLs. These studied showed that the PCR amplification of the TCR gamma gene can be a powerful tool in the diagnosis of T-cell NHLs.

A dramatic accumulation of glycogen in the brown adipose tissue of rats following recovery from cold exposure.

In a morphological study of brown adipose tissue (BAT) of rats returned after exposure to cold (+5 degrees C) to neutral temperature (+25 degrees C), striking periodic acid Schiff staining was observed, indicating substantial glycogen accumulation. Enzymatic analysis revealed that the glycogen content increased from the 4.05 +/- 0.51 (micromol glucose unit per gram of tissue, mean +/- SE) control value to 57.3 +/- 9.66 when the animals were returned to neutral temperature for 24 h after a 1-week cold period. Glycogen repletion was also observed in liver and skeletal muscle; however, the glycogen levels in these tissues never exceeded the control values. The accumulation of glycogen in the BAT started by the 3rd hour of replacement and peaked by the 24th hour. This glycogen was readily utilized during the next short cold exposure of the animals. The plasma leptin concentration was reduced at the cold temperature. The hexokinase II activity in the BAT increased to 29.3 +/- 1.46 vs the 11.8 +/- 1.06 control (mU/mg protein +/- SE) after a 1-week cold exposure and this level was maintained during the return to neutral temperature. The total glycogen synthetase (GStot) and the glycogen synthetase a activity also increased after a 1-week cold exposure and increased further during the replacement. The level of GStot reached 26.9 +/- 1.39 vs 9.54 +/- 1.43 control by the 24th hour of replacement. At the same time, the glycogen phosphorylase a activity declined during the replacement. The concentration of glucose 6-phosphate (an activator of GS) decreased in the cold but returned to normal during the replacement. These changes in the BAT are in favor of glycogen synthesis.

Distinct clonal origin of low-grade MALT-type and high-grade lesions of a multifocal gastric lymphoma.

AIMS: Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma and high-grade B-cell non-Hodgkin's lymphoma (NHL) of the stomach may occur simultaneously. To determine the clonal relationship between these tumours, we compared the immunoglobulin heavy chain gene (IgH) rearrangements of low and high-grade components of a multifocal gastric NHL. METHODS AND RESULTS: The complementary determining region 3 (CDR3) of the IgH gene rearrangements were polymerase chain reaction (PCR) amplified, cloned and sequenced. The analysis of the CDR3 sequences rearranged by tumour cells of low-grade MALT and the high-grade NHL revealed different nucleic acid sequences. CONCLUSION: These findings suggest that low-grade MALT and high-grade B-cell components of multifocal gastric NHL may represent unrelated clones.

[Pathologic diagnosis of mantle cell lymphoma based on histologic, cytologic, immunohistologic and genetic characteristics]. / A köpenysejtes lymphoma patológiai diagnózisa hisztológiai, citológiai, immunhisztológiai és genetikai jellemzók alapján.

Mantle cell lymphoma (MCL) is a clinocopathologic entity representing a broad histologic and cytologic spectrum from cystic to the blastic form. The histologic, cytologic heterogeneity of MCLs may lead to diagnostic confusion. The aim of this study was to reclassify NHLs registered as centrocytic lymphoma and centrocytoid-centroblastoma by the Lymphoma Reference Centrum at the Department of Pathology, University Medical School of Pécs between 1988 and 1995. 63 of 67 selected cases have been classified as mantle cell lymphoma according to histological, cytological appearance, and the pheno- and genotype of tumour cells. 48% of the cases showed diffuse while 52% showed nodular histological pattern. 27% of diffuse MCLs composed of classic MCL cells (small to medium-size cells) 40% blastic and 33% both small and blastic lymphoma cells. In 76% of the nodular MCLs the tumour consisted of small to medium-size cells 15% blastic while 9% both small and blastic lymphoma cells. In 99% of MCL the diagnosis was supported by CD5, CD20 and CD23 positivity and in 67% by the presence of cyclin D1-overexpression. The t(11;14) chromosome translocation PCR amplification was positive in 3 of 17 cases investigated. The authors conclude that MCLs represent a heterogeneous disease based on the cytology of the tumour cells. The nodular architecture was associated with classic MCL cells while the diffuse form was more frequently associated with blastic or combined cytological appearance. The correct diagnosis of MCL could be reached by tumour cell immunophenotyping, while molecular genetic methods proved to be informative only in part of the cases studied.

EBER oligonucleotide RNA in situ hybridization in EBV associated neoplasms.

In virus associated diseases identification of viruses in cells can contribute to the understanding of the pathogenesis and may also help to establish the diagnosis. In the present communication, the effects of the microwave pretreatment (MWP) and that of the proteinase-K enzymatic predigestion (PKD) on EBER RNA oligonucleotide in situ hybridization (EBER-RNA-ISH) (EBER: Epstein-Barr-Encoded-(Early)-RNA) were studied. The efficacy of two EBV detecting methods, latent membrane protein-1 (LMP-1) immunohistochemistry and EBER-RNA-ISH were also compared. Our results show that microwave pretreatment enhances the intensity of the ISH signals and preserves significantly better the structure of the tissues compared with enzymatic predigestion. EBER-RNA-ISH, mainly in the nasopharyngeal carcinoma cases, showed a more frequent positivity than the immunohistochemical reaction for LMP-1, however in case of the Warthin's tumor only the LMP-1 protein was expressed.

[CD30 positive large T-cell primary cutaneous lymphoma]. / CD30 pozitív, nagy T-sejtes primer cutan lymphoma.

The primary cutaneous CD30 positive large cell lymphoma is a rare tumor, confined to the skin. The characteristic clinical picture is a large, often exulcerating sometimes spontan regressing tumor or nodule. Dense infiltration of large, anaplastic or non-anaplastic T or non T, non B cell of the dermis is characteristic. Generalization, lymph node or internal manifestation is rare, the prognosis is favourable. A 25-year-old male patient is presented, in whom generalised skin symptoms-itching, reddish-brownish papules with central necrosis developed. Two years later general symptoms-fever, fatigue, lymph node and spleen enlargement, increased in white blood cell count with prominent eosinophilia, increase in CD4 number occurred. The histology and immunohistology of the skin and peripheral lymph node showed large, anaplastic, CD30 positive T cell infiltration. CHOP, then BACOP treatment resulted in regression of the skin and the internal symptoms.

[Anaplastic large cell lymphoma based on our clinicopathological cases]. / Az anaplasticus nagysejtes lymphomáról, eseteink klinikopatológiai elemzése kapcsán.

CD30(Ki-1) positive anaplastic large cell lymphoma (ALCL) is a distinct entity, in which the monoclonal antibody-positivity against the CD30(Ki-1) antigen of tumour cells has a diagnostic value. The histological subtypes of ALCL show also certain clinical differences. Except for some pediatric cases and cutaneous forms clinical outcome is very unfavourable despite of the various treatment methods. In this prospective study (follow-up of 11-60, median 16 months) clinicopathological data and treatment results of fifteen adult patients with ALCL were analysed, Mean age was 46 (16-69) ys with a bimodal tendency and a distinct female: male ratio (3:2) was observed. Early clinical stages (I-II/A-B, eight patients) dominated, and two main groups could be distinguished histologically (Hodgkin-related, ALCL-HR and common type, -CT in eight and seven patients), respectively. In all histological specimens CD30 antigen expression was detected. Additional immunophenotyping was performed in five cases (two 0-variant, two of B-cell and one of T-cell origin), respectively. A bulky disease, mainly in the mediastinum was observed in six cases, and a primary gastrointestinal localization in two other patients. In the treatment of these high grade malignant lymphomas a combination of cobalt irradiation and aggressive chemotherapy was applied (in elder the CHOP-regimen, in younger patients mainly the Pro-MACE-Cyta-BOM-protocol). In one relapsed younger patient autologous bone marrow transplantation was also performed. A complete or partial remission was achieved in thirteen patients (86.6%) but six patients expired after only a short response period to therapy. Overall survival was 19, whilst disease-free survival revealed to be 15 months. Eight of their living nine patients have a durable complete remission. Due to residual mediastinal mass after radiotherapy in three cases a permanent radiological follow-up is needed. Advanced age and clinical stages are considered to be unfavourable, whilst histological subtypes were indifferent prognostic factors, as well. Favourable results in therapy and durable complete remission in younger patients are probably caused by the their better tolerance of third-line aggressive chemotherapy.

[Clonality analysis of B-cell lymphoproliferative disorders by means of immunoglobulin heavy chain polymerase reaction]. / B-sejtes lymphoproliferativ kórképek klonalitásának elemzése immunglobulin nehézlánc polimeráz láncreakció segítségével.

The majority of B-cell non-Hodgkin's lymphomas (NHL) exhibit a highly specific immunoglobulin heavy chain (IgH) gene rearrangement as a result of sequential assembly of their Ig variable (VH), diversity (D) and joining (JH) region segments. The analyses of Ig gene rearrangements in B cells may help to differentiate reactive lymphoproliferations from NHLs, and to identify of their B-cell origin. The aim of this study was to reveal the usefulness of polymerase chain reaction analysis of the Ig gene rearrangement in the diagnosis of B-cell NHLs, using native and formol-paraffin embedded samples. The authors analysed 67 biopsy samples of immunohistochemically characterized lymph nodes diagnosed at the Department of Pathology. University Medical School of Pécs, between 1993 and 1995, using IgH gene polymerase chain reaction. The 67 samples included 10 reactive lymphoproliferations, 47 B-cell, 5 T-cell NHLs and 5 Hodgkin's diseases. In 54 cases, fresh, unfixed, in 13 cases, formalin-fixed samples have been used. The polymerase chain reaction amplification of the Ig heavy chain third complementary determining region (CDR 3) was performed by IgVH specific sense and JH specific antisense primer pairs. The polymerase chain reaction products were evaluated by agarose gel electrophoresis containing ethidium bromide. Sixty-four % of fresh, unfixed and 54% of formol-paraffin fixed B-cell NHLs samples showed clonal Ig gene rearrangement. The applied polymerase chain reaction technique did not show clonal amplification in reactive lymphoproliferations, T-cell NHLs or Hodgkin's disease. The polymerase chain reaction amplification of the IgH gene can be a powerful tool in the diagnosis of monoclonal B-cell lymphoproliferative disorders.

Autoimmunity, hyporeactivity to T cell mitogens and lymphoproliferative disorders following neonatal induction of transplantation tolerance in mice.

We have reported that, in A/J (A) (H-2a) mice, a partial tolerance to C57BL/10ScSn (B10) (H-2b) skin allografts and a high incidence of lethal lymphoproliferative disorders (LPD) can be induced by the neonatal i.v. injection of 2 x 10(7) semiallogeneic (B10 x A)F1 spleen cells (SC) (Végh, P., Baranyi, L. and Jánossy, T., Cell. Immunol. 1990, 129: 56). In this study, we show that the incidence and mortality of LPD were continuously growing from 1 month of age until the end of the experiment at 1 year (64% and 36%, respectively). Based on histology, 27% of the diseased mice suffered from lymphoid malignancies. In the remaining cases (73%), reactive histopathological changes were seen in the spleen, lymph nodes (LN), liver and kidneys. The proportion of CD4+ T cells in the spleen and LN as well as that of splenic B cells decreased, while the percentages of mature and immature myeloid cells doubled. The total cell number of each (sub)population, however, was elevated in both lymphoid organs. The cells taking part in the lymphoproliferation were of host (A) and not of donor (F1) origin. Preceding the development of apparent LPD, the SC, LN cell and thymus cell suspensions of 1-month-old tolerized mice showed reduced in vitro proliferative responses to T cell and T cell-dependent B cell mitogens (Con A or PWM), while their reactivity to a T cell-independent B cell mitogen (lipopolysaccharide) was essentially unimpaired. This hyporeactivity seems to be functional, because neither histology nor immunophenotyping by flow cytometry revealed significant alterations in the spleen and thymus of such animals, apart from a slight reduction in the ratio of CD4+/CD8+ T cell subpopulations in the spleen. The in vivo T cell-mediated immune response of the tolerized mice was practically normal to third party CBA/Ca (H-2k) allografts. Antithymocyte autoantibodies (ATA) were detected in the sera of 76% of the tolerized mice at 1 month of age (i.e., even before the mass appearance of LPD). ATA as well as antinuclear Ab were present in 65% of the adult tolerized mice, independently of the presence of LPD. Taken together, in A mice neonatally injected with (B10 x A)F1 SC, a partial, specific allograft tolerance and a chronic host-vs.-graft disease-like syndrome developed. The latter is manifested in hyporeactivity to T cell mitogens, development of autoantibodies and, subsequently, in progressive LPD and lymphoid malignancies.

Expression of an adhesion molecule and homing in B-cell chronic lymphocytic leukaemia: I. Application of the HEV-binding assay to a clinical series.

High endothelial venule (HEV)-binding of peripheral blood mononuclear cells (PBMCs) from 43 patients with B-cell chronic lymphocytic leukaemia (B-CLL) was investigated with a HEV-binding in vitro assay. Immunophenotyping of HEV-adherent PBMCs proved that most of them belonged to the B-cell proliferation. B-CLL cells stringently expressed CD44 molecules (Hermes-1, -3 and H90). The patients were subgrouped according to Binet's classification, as well as according to the organ manifestations, i.e. patients with B-cell monoclonal lymphocytosis of undetermined significance (B-MLUS) and patients with lymphocytosis (LY), lymph node enlargement (LN) and splenomegaly (SM). The HEV-binding activity of the cells was the highest in Binet stage A patients and in patients with B-MLUS (p < 0.05 in B-MLUS versus B-CLL LY, LN, SM). Based on these findings it is suggested that B-CLL patients show not only a clinical and immunophenotypical heterogeneity, but a diverse function of adhesion molecules.

[Experience with results of treatment of non-Hodgkin's lymphoma]. / Gastrointestinalis nem-Hodgkin lymphomák kezelésével szerzett tapasztalataink.

Thirty primary gastrointestinal non-Hodgkin's lymphoma treated between 1983-1990 were reviewed to reveal the efficacy of various treatment strategies. The average age at the diagnosis 53.6 (18-76) years. The histologic material were evaluated according to the Kiel classification: 22 patients had high grade malignant lymphoma (centroblastoma 8, immunoblastoma 6, lymphoblastoma 2, non classifiable 5, T-cell lymphoma 1) 8 patients low grade malignant lymphoma (lymphocytic 2, immunocytic 2, MALT lymphoma 1, centrocytoma 1, non-classifiable 1, pleomorph small cell lymphoma 1). 21 were primary gastric lymphoma, 5 involved the small intestine, 2 the ileocecal region, and 2 the large intestine. According to the Ann Arbor staging system 7 patients were stage I/E, 16 patients stage II/E, 5 patients stage III/E and 2 patients stage IV/E. Every patients underwent surgical resection. After surgical treatment high grade malignancies were treated with ProMACE-COPP (9) and CHOP-Bleo (10) polychemotherapy; low grade malignancies received VEP (5) and CVP (3) chemotherapy. 23 of 30 patients achived complete remission. The patients with low grade malignancy are in remission. All but one patients with high grade malignant gastric lymphoma achieved complete remission with a median of 37 (3-81) months relapse-free survival. Out of 5 cases in the small intestine only in 1 case was remission achieved. Histological type (Kiel) and surgical resection were the most important prognostic factors.

Blood vessels in human immunodeficiency virus-related lymphoadenopathy: high endothelial venules and lymphocyte migration.

The vasculature of 25 lymph nodes of patients with human immunodeficiency virus-related lymphadenopathy was investigated morphometrically. The number of small vessels, the morphological features of high endothelial venules and the migratory index of the lymphocytes passing through the high endothelial venules, as well as the stage-dependent change of each parameter, were analysed. Twenty reactive lymph nodes served as controls. The total number of vessels in the HIV-infected lymph nodes was relatively stable. However, the small vessels with flat endothelium increased in number, while the number of high endothelial venules decreased as the disorder progressed, and the decrease in the lymphocyte migration seemed to precede the change in the morphology of high endothelial venules. The presumptive role of these alterations in the pathogenesis of the investigated disorder is emphasized.

[Results of multicenter treatment of highly malignant non-Hodgkin's lymphomas]. / Kifejezett malignitású nem Hodgkin-lymphomák multicentrikus kezelésének eredményei.

One hundred and eleven consecutive patients with highgrade non-Hodgkin's lymphoma treated in three centres between 1983 and 1988 were analysed to assess the efficacy of different types of chemotherapy. The median age at presentation was 56.9 +/- 16.6 years. According to the Kiel classification histological subtypes were: centroblastoma (n = 45), immunoblastoma (n = 17), lymphoblastoma (n = 6), T cell lymphoblastoma (n = 9), histiocytoma (n = 2), and high grade unclassified (n = 32). Patients were clinically staged, 68 patients (61%) belong to stage I-II. and 43 had widespread disease (stage III-IV.). Remission was achieved in 81 cases [70 complete (CR) and 11 partial (PR) remission], 30 patients did not respond. The most effective modality of treatment was extended field irradiation completed with chemotherapy (81% CR, 7-year overall survival 65%) followed by ProMACE-COPP chemotherapy (67% CR, 4-year survival 40%) and CHOP-Bleo chemotherapy (65% CR, 7-year survival 25%). Age and histological subtype had no prognostic relevance, whereas clinical stage proved to have significant influence on remission and survival.

Malignant lymphomas of the breast.

Primary non-Hodgkin malignant lymphomas (ml) of the breast are infrequent (0.05-0.5% of all malignant breast tumours). In the present series, 10 cases seen between 1980-1989 from the files of the Malignant Lymphoma Reference Center, Pécs, Hungary, were re-evaluated. Nine out of the 10 cases were of B-cell origin, 4/10 of low grade and 6/10 of high grade malignancy. In the latter group there were 4 centroblastic ml-s. In one of them transformation of a low grade MALT-type ml to centroblastic ml was suspected. Another high grade B-cell ml was similar to the recently described mediastinal clear cell ml, B-cell type. At presentation, 7 out of 10 patients were in clinical stage IE. In the same period (1980-1989), 5 further cases with clinical suspicion of breast tumor had reactive lesions (florid follicular hyperplasia).

[Malignant lymphomas: pathomorphology and experiment]. / A malignus lymphomákról: pathomorphologia és experimentum.

The last fifteen years have provided a significant development in pathomorphological diagnosis of malignant lymphomas (ml), in clinical fellow-up of patients and in its therapy. Diagnosis is built on functional morphological basis (immunohistology). New methods have reslited in identification of new types of mls. On the basis of high number of cases registered in Lymphoma Reference Centre, specific organic distribution new entities can be determined. Perifollicular B-cellular mls of MALT type are frequent in gastrointestinal tract and are rare in Waldeyer ring and in lymph nodes. Flow cytometric determination of DNA content of cells proved to be very useful in diagnostics of mls, so the probably determination of aneuploid and proliferative activity, respectively. These parameters are of prognostic significance. Recirculation of lymphocytes may play a role in dissemination os nHmls. It can be studied in immunomorphological (in vitro) test ased on the interaction (adherence) of lymphocytes and of endothelial cells of high endothelial postcapillary venule. Our observations present that B-cellular CLL and clonal cells of plasma cellular leukemia show endothelial adherence, while multiple cells of myeloma do not.

Immunohistochemistry in lymphoproliferative diseases.

In diagnostic pathomorphology of lymphoproliferative diseases, immunohistochemical methods are of great importance. These methods help to elucidate the following issues: reactive or malignant nature of a lesion, origin of atypical cells (lymphoreticular or other), type of malignant lymphoma (Hodgkin's disease or malignant non-Hodgkin lymphoma, NHL), grade of malignancy, T- or B-cell origin and subtype of NHLs. All results of immunohistochemistry should be carefully scrutinized in the light of routine pathomorphological findings. The possibilities of immunohistochemistry are demonstrated by two examples: 1. Origin and stage of differentiation of B-cell chronic lymphocytic leukaemia cells with special emphasis on the presence of follicular dendritic reticulum cells in the lymph nodes of a few, otherwise typical cases of CLL. 2. Description of two cases of a new type of NHL that contains intrasinusoidal B-cells. Monoclonal plasma cells with immunoglobulins of the same isotypes as those of intrasinusoidal B-cells were observed in both cases. These findings suggest that the intrasinusoidal B-cells may be plasma cell precursors.

Comprehensive epidemiological and clinicopathological survey of Hodgkin's disease in Hungary.

To determine the epidemiological pattern and some clinicopathological features of Hodgkin's disease in Hungary, the data of 233 consecutive patients with the disease from seven counties, diagnosed between January 1983 and July 1987, were analysed on the basis of data from four cancer centers. Large variations were noted in incidence rates between the different regions of Hungary. The epidemiological pattern seems to vary from those reported in developed and developing countries. A sharp rise in the incidence of Hodgkin's disease occurred at the end of the second decade of patients' lives. More of our Hodgkin's patients are at advanced clinical stages, with systemic symptoms and a histological type of mixed cellularity, at the time of diagnosis, than in the western hemisphere. On the average, there is a 6-month period between the appearance of the first sign or symptom and the diagnosis. There is a lack of data outlining the epidemiological differences in the pattern of Central Europa. The aim of this study is to supply data for the etiopathogenetic research of Hodgkin's disease, as there is an important task to improve the unfavourable home situation, and to strive for earlier diagnosis in this disease.