Immunologic and cytochemical properties of histiocytic and mixed histiocytic-lymphocytic lymphomas

Prognostic Value of the Kiel Classification of Malignant Non-hodgkin's Lymphomas

The aim of the present research was to evaluate the prognostic value of the Kiel classification of malignant non-Hodgkin's lymphomas. For this purpose a series of 100 consecutive, previously untreated adults with advanced malignant non-Hodgkin's lymphomas was analyzed. The median age of the patients was 54 years; 61 patients were males. Although the number of the various groups considered was limited, a statistically significant difference (p < 0.001) was found in the median survival of patients with lymphomas of low-grade malignancy (lymphocytic, lymphoplasmacytoid, centrocytic, centroblastic-centrocytic lymphoma) and lymphomas of high-grade malignancy (centroblastic, lymphoblastic, immunoblastic lymphoma). A difference in survival (p < 0.001) was also observed among the patients with lymphocytic lymphoma and those with centroblastic-centrocytic lymphoma, whereas no significant difference in survival was found between the histological subtypes of high-grade malignant lymphomas. Our observations support the opinion that the Kiel classification is useful in clinical practice to distinguish the histological types with a better prognosis from those with a worse one; in addition this classification appears to be of conceptual value.

Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163

Histiocytic sarcoma (HS) is a rare but controversial hematopoietic neoplasm. In the past, malignancies have been misclassified as histiocytic tumors due to overlapping histologic features and inadequate phenotypic data. CD163, a recently characterized hemoglobin scavenger receptor, appears to be a 'specific' marker of histiocytic lineage and a promising diagnostic tool for evaluating histiocytic neoplasms. Five cases of HS were studied to further elucidate the clinicopathologic features of these rare tumors and to demonstrate the diagnostic utility of CD163. Criteria for diagnosis included histologic and immunohistochemical evidence of histiocytic differentiation, CD45 positivity, and exclusion of lymphoid, epithelial, melanocytic and dendritic cell phenotype. Sites of disease included the colon (two cases), palate, inguinal lymph node, and testis. The clinical course was aggressive in 4/5 patients (survival=2-15 months). One patient with localized disease of the palate, survived 17 years after diagnosis. All patients with poor survival had tumors > or =3.5 cm. Histologically, all cases showed diffuse architecture with large, discohesive polygonal cells. Spindling of cells was focally noted. Hemophagocytosis was identified in 3/5 cases. A prominent inflammatory background was present in 4/5 tumors. All cases were immunoreactive for CD45, CD163, CD68, and lysozyme. S-100 was focally positive in 4/5 cases. Antibodies for melanocytic, epithelial, lymphoid, and dendritic cell markers were negative. Molecular studies showed monoclonal IgH gene rearrangements in three cases. Our findings suggest that HS is an uncommon neoplasm frequently extranodal in presentation and aggressive in behavior, with rare exceptions. Stage of disease and possibly tumor size are significant prognostic indicators. Molecular studies remain controversial in the diagnosis. The morphologic and phenotypic features are relatively uniform; however, the diagnosis requires exclusion of more common neoplasms by extensive immunophenotypic studies. CD163 appears to be a specific histiocytic marker and is important in establishing the diagnosis of HS.

Phenotypic and cytogenetic characteristics of a new Epstein-Barr virus negative cell line (SKW 4) derived from a B-cell lymphoma

A new Epstein-Barr virus nuclear antigen (EBNA) negative cell line SKW 4 has been established in vitro from a patient with diffuse histiocytic lymphoma. The SKW 4 seems to be an authentic human tumour cell line as evidenced by its EBV negativity, monoclonality and aneuploidy tested during early in vitro passage. The cell line expresses surface mu and kappa-chains, HLA-DR antigen, C3 and Fc receptors and B-cell lineage antigens. The karyotypic analyses demonstrated many numerical and structural aberrations. No Burkitt lymphoma associated translocations (t8;14, t2;8, t;22) were detected, but most of the markers found are those commonly associated with various types of human cancer. The SKW 4 thus represents the most common type of 'histiocytic lymphoma', that with a B-lymphoid cell phenotype, but is unique among HL derived lymphoma lines in its strong expression of a Helix pomatia A agglutinin binding surface glycoprotein of an apparent molecular weight of 75 000 daltons.

Cytochemical reactions in bovine and ovine lymphosarcoma

Cytochemical reactions with a panel of special stains were explored in peripheral blood and lymph node cells of animals with the adult, calf, and thymic types of bovine lymphosarcoma as well as lymphosarcoma in sheep induced with the bovine leukosis virus. These results were compared with normal lymphoid cells. Cytochemical methods included Sudan black B, periodic acid-Schiff, acid phosphatase and three esterases. Cells from ovine lymphosarcomas and a thymic type of bovine lymphosarcoma were distinctively positive to the alpha naphthyl acetate esterase reaction. These cytochemical reactions which were obtained with standard cytochemical methods should aid in the characterization and classification of lymphoproliferative disorders in animals, especially when combined with immunologic surface markers.

Clinical, hematologic, and pathologic features of leukemic T-cell lymphoma

Cells obtained from malignant lymph nodes and the peripheral blood of 106 patients with non-Hodgkin's lymphomas were examined for T- and B-cell characteristics. Surprisingly, 79 cases were of the T-cell type on the basis of spontaneous rosette formation with sheep erythrocytes (E-rosettes). Of the remaining cases, 15 were B-cell in nature (monoclonal S-Ig positive), seven were non T-, non B-cell and four cases were undetermined. Forty-nine (62.0%) of the T-cell malignancies were of a leukemic variety, characterized by pleomorphism in the peripheral blood cell size, and histological appearance. Most of the leukemic T-cells showed obvious lymphocytic differentiation, with condensed nuclear chromatin and scant cytoplasm, although in many of the cases, the lymphomatous infiltrate was dominated by large or pleomorphic lymphoid cells. All tumors were of a diffuse variety, and on histologic examination included a mixed type (21 cases), PDLL forms (15 cases), a large lymphoid cell type (eight cases), and WDLL forms (five cases). Although the mixed type with a pleomorphic lymphoid infiltrate was distinctive, there has been considerable variation from case to case. Clinically this unusual t-cell, leukemic variety of non-Hodgkin's lymphomas primarily involved middle-aged and elderly subjects, and was characterized by wide spread organ invasion (preferentially to the liver, spleen and skin), resistance to chemotherapy, and a poor prognosis. A mediastinal mass was not observed in all cases. The patients had a median survival of only ten months.

Immunologic characterization and ultrastructural correlations for 125 cases of B- and T-cell leukemias: studies of chronic and acute lymphocytic, prolymphocytic, lymphosarcoma cell and hairy cell leukemia, Sézary's syndrome, and other lymphoid leukemias

Peripheral blood from 125 patients (160 specimens) with various types of lymphoid leukemias was evaluated for B- and T-cell markers (E rosettes, C3 and Fc receptors, and surface immunoglobulin). B-cell leukemias (comprised 82% of the series and included chronic lymphocytic leukemia (69/71 cases), acute lymphocytic leukemia (1/18 cases), lymphosarcoma cell leukemia (15/18 cases), prolymphocytic leukemia (one case), plasma cell leukemia (one case), hairy cell leukemia (12/12 cases), and leukemic phase of "histiocytic" lymphoma and Waldenström's macroglobulinemia (one case each). Within the B-cell group, certain leukemias exhibited distinct patterns of lymphocyte surface markers. Three cases of lymphosarcoma cell leukemia revealed both T and B cell markers (E-rosette formation and monoclonal SIg). T-cell leukemias comprised 12% of the series and included chronic lymphocytic leukemia (2/71 cases), acute lymphocytic leukemia (11/18 cases), and Sézary's syndrome (2/2 cases). In eight cases of acute lymphocytic leukemia, the majority of the cells demonstrated no definable markers (non-B, non-T cell type). Ultrastructural studies, performed in selected cases, were correlated with immunologic findings. Distinctive morphologic features were observed for different variants of B- and T-cell leukemias. Neoplastic cells of T-cell leukemias revealed a greater nuclear irregularity than B-cell proliferations, as assessed by the nuclear contour index (ratio of circumference to the square root of the nuclear area). The cytoplasmic feature most predictive of immunologic cell type was abundant rough endoplasmic reticulum, suggesting plasmacytoid differentiation, observed in some B-cell proliferations.

Immunohistological studies on primary reticulosis of the canine brain

Brains of 17 dogs with primary reticulosis, and of two with metastatic and one with primary lymphosarcoma, were examined by immunohistologic techniques with antisera against the major immunoglobulin classes of the dog. On the basis of immunoglobulin in tumour cells, two reticuloses were reclassified as primary lymphosarcomas of the brain. The tumour cells in three other dogs with neoplastic reticulosis and in six dogs with microgliomatosis did not contained immunoglobulin. Many cells in inflammatory reticulosis were immunoglobulin-bearing. Although some of these lesions could have been lymphosarcomas, insufficient data were available to ascertain either an inflammatory or a neoplastic nature. It was concluded that some lesions previously classified as reticulosis are in fact primary histiocytic lymphosarcomas of the brain, while others may be true reticulosarcomas.

An immunocytochemical study of non-Hodgkin's lymphomas

Lymph node specimens obtained intraoperatively and/or at autopsy from 89 patients with non-Hodgkin's lymphoma were studied immunohistochemically. The peroxidase anti-peroxidase (PAP) technique was used for detecting monoclonal cytoplasmic immunoglobulin (CIg) and for determining the classes and types of immunoglobulins in the tumors. Following rigid criteria, monoclonal CIg was demonstrated in four (16%) of 25 cases of nodular, poorly differentiated lymphocytic lymphoma (NPDL); in three (14%) of 21 cases of diffuse, poorly differentiated lymphocytic lymphoma (DPDL); and in 13 (30%) of 43 cases of diffuse histiocytic lymphoma (DH). Of the four NPDL patients, two had the M kappa, one the A kappa, and one the lambda chain type. Of the three DPDL patients, one had the M kappa, one the G kappa, and one the lambda chain type. Of the 13 DH patients, five had the M kappa, four the A kappa, one the GM kappa, one the A kappa, one the G kappa, and one the kappa chain type. In two DH patients negative for cytoplasmic immunoglobulins, cytoplasmic lysozyme was present, indicating the histiomonocytic nature of the tumor cells. There was no significant difference between the overall survival rates for the DH patients with or without monoclonal CIg. In all three types of lymphoma studied, we encountered many patients (67%) who had tumor cell populations without demonstrable CIg and few patients (11%) with polyclonal CIg. There are several possible reasons why many of the patients were PAP-negative and why some had polyclonal cell populations. The PAP method may be useful in establishing the monoclonal nature of neoplastic lymphoid cell populations.

Composite lymphoma: report of a unique case

Composite lymphoma with more than one well demarcated non-Hodgkin's or Hodgkin's lymphoma in the same organ or mass is rare. Only 22 such cases, each with two lymphomas, have been reported. We describe a unique case in which there were three non-Hodgkin's lymphomas, according to the Rappaport's nomenclature, in the spleen and abdominal lymph nodes.

Malignant lymphomas as tumours of the immune system

Malignant lymphomas have traditionally been classified on solely morphological grounds. With new immunological and cytochemical techniques, it has been possible to characterize normal cells of the T-lymphocyte, B-lymphocyte, and monocyte-macrophage system. Application of these methodologies to malignant lymphomas has established their nature as neoplasms of the immune system. Within the B-lymphocyte system it is possible to identify subpopulations responsible for Burkitt's tumour, follicular (nodular) lymphomas, lymphocytic lymphomas of intermediate differentiation and well differentiated lymphocytic lymphomas. The T-lymphocyte system includes lymphoblastic lymphomas, mycosis fungoides, and Sezary's syndrome. Large-cell lymphomas are diverse, but the majority are tumours of transformed lymphocytes, usually of the B-lymphocyte system. The precise nature of the neoplastic cells of Hodgkin's disease (i.e., Reed-Sternberg cells and their mononuclear counterparts) has not yet been established. Despite previous suggestions of a B-lymphocyte or T-lymphocyte origin, recent studies with in vitro cultivation have strongly suggested derivation from the monocyte-macrophage system.

A critical analysis of the classifications of non-Hodgkin's lymphomas

The Rappaport classification of non-Hodgkin's lymphomas was proposed almost a quarter century ago, before the advent of modern immunology. This classification, which is based entirely on morphologic features, has proved its clinical usefulness. In light of recent scientific advances, however, its terminology is not appropriate. Five new classifications have been proposed recently, each claiming to have more merit than the others. The purpose of this study is to critically analyze and evaluate these newly proposed classifications to determine which classification is conceptually and scientifically acceptable as well as clinically useful. The results of the study show that there are more similarities than differences among the Rappaport. Lukes and Collins, Dorfman, British, and WHO classifications; the Kiel classification, however, is fundamentally different (Tables 8, 9, 11). None of these classifications can be used in its proposed form. Based on the analysis of these classifications, a compromise working classification is proposed which incorporates the relevant concepts and terminology from the Rappaport, Berard, Dorfman, WHO, and Lukes and Collins classifications (Tables 15, 16). The proposed compromise classification is an attempt to reconcile the various classifications, and to stimulate others to offer modifications which may bring about a final solution to the problem of classification of non-Hodgkin's lymphomas.

Non-Hodgkin's lymphomas: an ultrastructural study correlating morphology with immunologic cell type

Ultrastructural studies were performed on 40 B-cell and 14 T-cell lymphomas of non-Hodgkin's type (NHL). Most B-cell lymphomas were comprised of neoplastic cells with morphologic features compatible with a follicular center cell origin. Dendritic reticulum cells and their desmosome-associated processes, characteristic of germinal centers, were observed in all 11 cases of nodular poorly differentiated lymphocytic lymphoma and in one of two cases of nodular "histiocytic" lymphoma, but were not identified in the lymphomas with a diffuse growth pattern. Desmosomes were observed between dendritic reticulum cells and were not found between lymphoid cells. Large neoplastic cells comprising lymphomas of "histiocytic," mixed lymphocytic "histiocytic," and "undifferentiated" types were characterized ultrastructurally and immunologically as lymphoid cells. Malignant lymphomas of well and moderately well differentiated lymphocytic types (7 cases) revealed B-cell markers, and represented a distinct homogenous group of neoplasms, with electron microscopic features most closely resembling follicular cuff lymphocytes. T-cell malignancies included lymphoblastic lymphomas (3 cases), large cell ("histiocytic") lymphomas (4 cases), lymphoepithelioid cell ("Lennert's") lymphomas (2 cases), mycosis fungoides (3 cases) and diffuse poorly differentiated lymphocytic lymphomas (2 cases). A consistent finding in the T-cell proliferations was the presence of small and/or large lymphoid cells with extremely irregular and/or convoluted nuclei, which occurred in varying proportions and with variable degrees of nuclear complexity. The nuclear irregularity evident in the neoplastic T cells was distinguishable from that observed for lymphoid cells of B-cell lymphomas. In comparing the cytoplasmic features of the T- and B-cell neoplasms ultrastructurally, the only distinguishing feature was the presence of well developed granular endoplasmic reticulum with dilated cisternae, i.e., plasmacytoid features, predictive of a B cell origin.

Chronic lymphocytic leukemia in association with a second lymphoproliferative disorder: response to chemotherapy in two cases

The development of either histiocytic lymphoma or Hodgkin disease in association with pre-existing chronic lymphocytic leukemia has been described in the literature as a terminal event. We describe two patients in whom the diagnosis of a second malignant lymphoma was made during life and who achieved objective clinical response after a change in therapy to a more aggressive combination of drugs. We conclude that patients with chronic lymphocytic leukemia who have had a sudden change in their clinical course should have thorough reevaluation, looking specifically for the development of a second lymphoproliferative disorder. If this is discovered, more aggressive therapy should be initiated.

Biology of the human malignant lymphomas. IV. Functional characterization of ten diffuse histiocytic lymphoma cell lines

Ten consecutive diffuse histiocytic lymphoma (DHL) cell lines established in our laboratory were studied for the presence of Epstein-Barr virus (EBV) genomes, lysozyme, nonspecific esterase and other cytochemical reactions, phagocytic activity, cytoplasmic immunoglobulin light and heavy chains, and surface receptors to sheep erythrocytes, complement, and the Fc fragment of immunoglobulin. In agreement with previous studies performed on biopsy specimens, our results indicate that the diffuse histiocytic lymphomas, as a histopathologic entity, represent a heterogeneous group of neoplasms, the majority of which are B-lymphocyte in origin. The cell lines appear to fall into three categories based on the following criteria: 1) presence of monoclonal cytoplasmic immunoglobulins (B-lymphocytic type, 6/10 cell lines); 2) presence of non-specific esterase, phagocytic activity, and/or lysozyme (histiocytic type, 2/10 cell lines); and 3) absence of all lymphoid and histiocytic cell characteristics (null cell type, 2/10 cell lines). Despite the fact that many of the lymphoma patients had positive serologies to EBV antigens, all of the DHL cell lines were negative for the presence of EBV genomes. Both of the two B-lymphocytic type and one of the two histiocytic type lines tested were susceptible to infection with EBV, as indicated by synthesis of early antigen and also, in a small proportion of the infected cells, of viral capsid antigen. These prototypic DHL cell lines may permit the development of new criteria for the differential diagnosis and treatment of this highly malignant and diverse group of lymphomas.

Surface markers and functional properties of non-Hodgkin's lymphoma cells in relation to histology

Cells from 32 adult patients with non-Hodgkin's lymphoma were studied with respect to surface markers and functional properties in short-term culture. Twenty-six lymphomas were of B-cell origin, including all nodular and diffuse lymphocytic lymphomas. Three tumors were of T-cell origin (one histiocytic lymphoma and two undifferentiated lymphomas). In the remaining three cases (histiocytic lymphomas) the immunological nature of the tumor cells could not be determined. All reactivity to mitogenic stimuli of cells from B-cell lymphomas was due to residual normal T cells. In follicular lymphocytic lymphomas more reactive T cells prevailed among the malignant B cells than in diffuse lymphocytic lymphomas. Heterogeneity among B-cell lymphomas was indicated by differences in intensity of fluorescence with anti-Ig reagents and in stimulatory capacity in mixed lymphocyte culture. T-cell lymphomas were characterized by high percentages of T cells together with impaired responses to stimuli. The results of immunological studies correlated well with the histological classifications of Rappaport, Lukes and Lennert.

Lymphomas of the gastrointestinal tract: a study of 117 cases presenting with gastrointestinal disease

A study was made of 117 patients who presented with gastrointestinal lymphoma. The occurrence was 48 in the stomach, 37 in the small intestine, 13 in the ileocecal region, two in the appendix and 11 in the large intestine. In six cases, multiple sites in the gastrointestinal tract were involved, but in five cases this appeared to be secondary to massive mesenteric or retroperitoneal lymph node disease. Using Rappaport's classification, diffuse histiocytic lymphoma was the most frequent histologic type and constituted 60% of the cases. Nodular lymphomas comprised 10% of the total, nodular poorly differentiated lymphocytic lymphoma forming the majority of this group. Ten of the lymphomas were undifferentiated, 5 of Burkitt's type and 5 non-Burkitt's type. Five were Mediterranean-type lymphomas associated with plasma cell infiltration of the adjacent mucosa, and only two cases of primary Hodgkin's disease were encountered. Two lymphomas could not be classified. Eight percent of the cases showed plasmacytoid changes and were classified as a distinct subgroup of the parent lymphoma rather than as examples of extramedullary plasmacytoma. Gastrointestinally lymphomas occurred most frequently during the fourth to seventh decades. However, nine lymphomas occurred in children younger than 16 years of age. In comparison to adults, the childhood lymphomas showed a number of notable differences with respect to sex distribution, site of involvement and histologic type. Information concerning the extent of the disease at the time of diagnosis was available in 75 cases. Of these, 49% of the lymphomas were confined to the affected viscus and 33% had associated regional lymph node involvement; the remaining 18% had mode widespread disease. In 44 patients information on the spread of disease was available and in 48% there was extra abdominal spread. Prognosis appeared to correlate best with the stage of the disease rather than the histologic type.

CLL and diffuse histiocytic lymphoma in one patient: clonal proliferation of two different B cells

A case report is presented of a 77-year-old woman suffering from a composite lymphoma, known as Richter's Syndrome, consisting of chronic lymphocytic leukaemia (CLL) and diffuse histiocytic lymphoma. Light-microscopic investigation revealed the presence of CLL cells in the blood and bone marrow and a combination of CLL cells and large immunoblastic cells in the lymph node. Immunological investigation showed that both malignant cell types were B cells. The CLL cells carried a monoclonal surface immunoglobulin (S-Ig) micron lambda, and the immunoblastic cells had a monoclonal S-Ig micron K. These findings indicated that both clonal lymphoproliferative diseases were probably derived from different tumour stem cells.

Reticulum cell sarcoma (histiocytic lymphoma) of the orbit

The clinical and pathologic features of 13 patients with biopsy-proven reticulum cell sarcoma of the orbit are reviewed. All of the patients were adults, in contrast to many previous reports that have emphasized how common this tumor is in children. Eight patients presented with proptosis and without prior diagnosis of lymphoma, and 5 patients developed orbital deposits in the course of a known systemic lymphoma. Of the 8 patients whose orbital biopsies established the diagnosis, 4 were found concomitantly to have other sites of disease, and 4 patients developed other evidence of lymphoma from 2 to 15 months after orbital biopsy. None of the cases in this series was interpreted as a primary orbital lymphoma. The histopathologic findings, the problem of histogenesis, and the need for systemic staging of cytologically malignant orbital lymphoma are discussed.

Classification of lymphomas

Malignant lymphomas are neoplasms of cells of the lymphoreticular or immune system. Classification of these neoplasms has long been controversial and confusing. In recent years, considerable progress has been made in establishing useful and prognostically significant classifications of lymphomas. Currently, lymphomas may be divided into two main groups: Hodgkin's disease and non-Hodgkin's lymphomas. The Rye classification of Hodgkin's disease is now widely accepted and used throughout most of the world. In contrast, considerable conflict exists about the schemes of non-Hodgkin's lymphomas. The traditional classifications of non-Hodgkin's lymphomas currently used by most pathologists are based purely on morphologic grounds, and, despite the fact that they may be conceptually incorrect, they have often been shown to be useful for clinicopathologic studies. New or modern but yet untested schemes based not only on morphologic criteria, but also on recent immunologic techniques, have been proposed. This work will review the classifications of Hodgkin's disease and the non-Hodgkin's lymphomas, emphasizing the currently used schemes, describe the major modern classifications of lymphomas, and discuss and illustrate the subclasses of lymphomas and the differential diagnoses of the various types of lymphomas from nonlymphomatous proliferations which may mimic them.

Demonstration of immunoglobulin production by tumor cells in non-Hodgkin's and Hodgkin's malignant lymphomas and its significance for their classification

Combined application of morphologic, immunochemical, and immunologic methods has led to a reinterpretation of non-Hodgkin's lymphomas and to the establishment of the Kiel classification. In the present paper, the main Ig-producing entities are considered. These are: 1. Chronic lymphocytic leukemia of the B-type (B-CLL)--a proliferation of lymphocytes and a few so-called prolymphocytes and lymphoblasts. The mean tissue IgM value is slightly increased; the serum IgM level is normal or reduced. The tumor cells bear SIg, and a majority of them have a receptor for C3d but always lack CIg and are usually devoid of receptors for C3b. 2. Lymphoplasmacytoid immunocytoma--a mixed proliferation of lymphocytes and centrocytes, blast cells, plasma cells, or plasmacytoid cells. The tissue Ig content is most often (91%) and most highly increased in this group, whereas the serum Ig level is increased in only 20% of the cases. The tissue IgM of 17 cases was shown to be monoclonal by IEF. Most tumor cells have SIg and a variable numbear CIg. The tumor cells bear both complement receptor subtypes, only a receptor for C3b, or no complement receptors at all. 3. Centroblastic/centrocytic lymphoma--usually a follicular proliferation of abundant small germinal center cells (centrocytes) and some large germinal center cells (centroblasts). The tumor cells bear SIg and both complement receptor subtypes. The C3b- and C3d-positive cells are located in the follicles, as in nonneoplastic lymphatic tissue. 4. Centrocytic lymphoma--a purebred, diffuse proliferation of the small germinal center cells (centrocytes). These cells bear SIg and receptors for C3b and C3d but usually lack CIg. 5. Centroblastic lymphoma--a proliferation of the large germinal center cells (centroblasts). 6. Lymphoblastic lymphoma of Burkitt's type. 7. Immunoblastic lymphoma--a diffuse proliferation of large basophillic cells resembling immunoblasts. The tissue IgM content is increased in 60% of the cases. It proved to be monoclonal with IEF in all five cases studied. The cells of five cases with increased tissue Ig content bore SIg. Nearly half of the cases studied showed CIg. Besides non-Hodgkin's lymphomas, paraffin sections of 87 biopsies from Hodgkin's disease were investigated for CIg in Hodgkin's and Sternberg-Reed cells. These cells stained positively in 68 cases, most often for IgG, followed by IgD. In five cases of the lymphocyte-depleted type, the staining of the Hodgkin's and Sternberg-Reed cells was restricted to one light chain type.

Cytochemical profile of human haematopoietic biopsy cells and derived cell lines

Twenty-three human haematopoietic cell lines, normal and mitogen stimulated peripheral blood lymphocytes and tumour material from fresh leukaemias, myelomas and lymphomas were investigated with a panel of cytochemical reactions. Normal and mitogen stimulated lymphocytes, non-neoplastic lymphoblastoid cell lines (LCL), lymphoma lines with B-lymphocyte characteristics, chronic lymphocytic leukaemia and fresh lymphocytic lymphomas reacted weakly or negatively with all stains. T-lymphocyte acute leukaemia lines were PAS and alpha-naphtyl acetate esterase positive. Myeloma lines and fresh myelomas were strongly beta-glucoronidase positive. A histiocytic lymphoma cell line was strongly esterase positive with naphtol AS-D acetate esterase inhibited by NaF. The three fresh histiocytic lymphomas, however, reacted as the lymphocytic lymphomas suggesting a lymphoid origin. A myeloid leukaemia line was strongly positive for acid phsophatase. No major disagreement was noted between the reactivity of established neoplastic lines and the corresponding fresh biopsy cells indicating an unaltered qualitative expression of enzyme production after prolonged in vitro culture.

Acute myelomomocytic leukemia terminating in histiocytic medullary reticulosis: cytochemical, cytogenetic and electron microscopic studies

A case of acute myelomonocytic leukemia terminating in histiocytic medullary reticulosis is reported. The evolution of a single cellular clone presenting with progressive change of the morphological features of the leukemic cells towards more anaplastic elements endowed with prominent phagocytic properties is suggested on the basis of both cytochemical and chromosomal data. The histiocytic nature of the malignant proliferating cells and platelet phagocytosis has been confirmed by electron microscopic investigation. The main pathogenetic explanations of the evolutionary patterns of the disease are discussed with relation to: a) involvement of a common stem cell giving rise to different proliferative patterns of cells in a multiphasic sequence; b) release of dysplastic platelets and defective erythrocytes with massive sequestration by histioid phagocytic cells; and c) coexistence of two different disorders.

Prognostic significance of lymphocyte surface markers in adult non-Hodgkin's malignant lymphoma

Neoplastic tissues from 75 adults with non-Hodgkin's malignant lymphoma were examined for B and T lymphocyte surface markers. All nodular lymphomas were B-cell type. Of 40 diffuse lymphomas, 23 were B, 5 were T, and 12 were "null" type. Patients with nodular lymphoma survived significantly longer than those with diffuse lymphoma (P = 0-00003). For patients with diffuse lymphoma, however, surface markers provide prognostic information not obtainable by histological classification as "poorly differentiated lymphocytic" or "histiocytic". Patients whose malignant cells had B markers survived significantly longer than those whose malignant cells had no markers (P=O-008). Survival of patients with diffuse lymphoma was best predicted by a classification utilising both surface markers and histological appearances. Differences in survival among patients with B-cell and "null" or T-cell lymphomas may relfect differences in sensitivity to specific drugs.

Mononuclear cells in human synovial fluid. Identification of lymphoblasts in rheumatoid arthritis

A simple method was developed to identify large mononuclear (LMN) cells in human synovial fluid based on morphology and staining with Sudan black B. All cells were classified as monocyte-derived macrophages (MDM), lymphoblasts (LB), or synovial lining cells (SLC). Lymphoblasts were seen in 58 of 60 rheumatoid fluids (mean: 69 +/- 18% LB per LMN cells). However lymphoblasts were rarely seen in synovial fluids from patients with crystal-induced synovitis or bacterial infections.

Establishment and characterization of a human histiocytic lymphoma cell line (U-937)

A human hematopoietic cell line (U-937) with exceptional characteristics was derived from a patient with generalized histiocytic lymphoma. The morphology of the cell line was identical to that of the tumor cells in the pleural effusion from which the line was derived. Since Epstein-Barr virus (EBV) carrying diploid lymphoblastoid cell lines unrelated to the tumor population often become established in vitro from non-Burkitt lymphoma explants, several parameters were studied to discriminate the U-937 from such lines: morphology in vitro, growth characteristics, cytochemistry, surface receptor pattern, Ig production, lysozyme production, beta2-microglobulin production, presence of EBV genome and karyotype. In all these respects U-937 differed from prototype lymphoblastoid cell lines. The histiocytic origin of the cell line was shown by its capacity for lysozyme production and the strong esterase activity (naphtol AS-D acetate esterase inhibited by NaF) of the cells. It is therefore concluded that the U-937 is a neoplastic, histiocytic cell line.