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

The 2022 classifications of lymphoid neoplasms : Keynote

Classification of hematological neoplasms in the past 25 years has been generated through international efforts to achieve broad consensus among professionals. In recent years, the understanding of lymphoid neoplasms has advanced notably, particularly with the impact of genomic studies. Two classifications of these neoplasms were produced in 2022. The International Consensus Classification (ICC) was generated following the same successful process used for the third, fourth, and updated fourth editions of the World Health Organization (WHO) Classification of Hematologic Neoplasms, coordinated by a steering committee approved by the Executive Committees of the European Association for Haematopathology and the Society of Hematopathology. The topics were prepared by different working groups and subsequently discussed in the clinical advisory committee (CAC) meeting with the participation of a large group of pathologists, clinicians, and scientists who all approved the classification after reaching consensus on all topics. Simultaneously, the International Agency for Cancer Research (IARC) of the WHO has produced the fifth edition of the classification of these neoplasms with a group of professionals appointed by the agency who discussed the proposed classification in different meetings. The definition and criteria for diagnosis of many entities have been refined in both proposals. Terminology for some diseases has been adapted to the current knowledge of their biology. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many entities. Although most categories are similar in both classifications, there are also conceptual differences and differences in the diagnostic criteria for some diseases.

Non-Hodgkin's Lymphoma in the Elderly: A Retrospective Evaluation of Toxicity Related to Aggressive vs. Conservative Treatments

The outcome of 70 elderly patients aged 65 years or more (median, 71 years) with non-Hodgkin's lymphoma (NHL) treated between 1973 and 1981 with aggressive (AM) or conservative modalities (CM) was retrospectively evaluated. A significantly higher incidence of lethal and severe toxicity was observed in patients treated with AM than in those treated with CM (32 % vs 3 %, p < 0.01), with 10 % treatment related deaths in the AM group. Only 56 % of the deaths were attributed to NHL; other major causes were treatment-related deaths, infection and cardiac diseases. No significant difference in response and survival was found between AM and CM groups (complete remission rates were 35 % vs 42 %, and 10 year survival rates were 31 % vs 19 %, respectively), but the prevalence of stages III-IV in patients treated with AM makes these results meaningless. Prospective randomized trials with AM vs CM are clearly needed in elderly patients with advanced unfavorable NHL.

Imaging features of primary extranodal lymphomas

Lymphomas are generally considered tumours of lymph nodes, but up to 40% arise extranodally. This group shows distinctive pathological, radiological, and clinical features. Different subtypes of extranodal lymphoma may show sufficiently specific radiological features to be of significant value in both establishing a diagnosis of lymphoma and ascertaining the exact subtype. Rapidly evolving lymphoma classifications and emergence of new entities have, however, hampered the accurate description of these features in the literature. In this review, we discuss the radiological appearances, using a variety of imaging methods, of the full spectrum of primary extranodal lymphomas, categorized according to the current World Health Organisation classification.

[The history of lymphoma classifications with special consideration of cutaneous lymphomas]

For modern evidence-based medicine, classification systems are necessary to guarantee a uniform approach for therapy and for estimating prognosis. The comparability of clinical studies and international communication require a common language and are only possible with modern international classification systems. But because all classifications are artificial, they only mirror the current state of knowledge and may change dramatically over decades. This review discusses the history of lymphoma classifications systems with a special focus on the topic of primary cutaneous lymphomas, emphasizing special problems in terminology.

Elderly patients with non-Hodgkin's lymphoma: population-based results in The Netherlands

BACKGROUND

To compare characteristics, treatment and outcome of patients > or = 70 years with patients < 70 years in a population-based non-Hodgkin's lymphoma (NHL) registry.

PATIENTS AND METHODS

All new patients with NHL (n = 1168) in a geographically defined region in the western part of The Netherlands were registered during a nearly 10-year period. Patient, tumour and treatment characteristics, response to therapy and survival were analysed for both age groups. An age-adjusted prognostic index was determined for elderly patients with aggressive lymphoma.

RESULTS

The elderly comprised 41% of the registered patients. There were significantly more females, a preponderance of intermediate-grade histology (diffuse large B-cell lymphoma) and a lower performance status. Incomplete staging in the elderly was mostly due to the omission of a bone marrow biopsy. With respect to WF grading the complete remission rate (except for patients with low-grade/stage I NHL, patients with extranodal NHL and for patients with intermediate grade/extensive NHL) and overall survival at five years (except for patients with low-grade/stage I NHL and for patients with intermediate-grade/extensive NHL) were significantly inferior in the elderly. With respect to the R.E.A.L. Classification the exceptions were in patients with high grade MALT lymphomas (elderly good) and patients with mantle-cell and peripheral T-cell lymphomas (younger group bad too). However, once complete remission was reached, the disease-free survival did not differ significantly between the two age groups, emphasising the importance of achieving complete remission. Although 65% of the classified elderly patients presented with intermediate-grade NHL, only 26% of the elderly patients treated with chemotherapy received anthracycline-based chemotherapy. In the elderly, lymphoma (treatment-related toxicity included) contributed to death in 70% and concomitant disease (other malignancy included) in 30%, versus 78% and 22%, respectively, for the younger group (P = 0.04). The age-adjusted prognostic index, made up of the factors serum LDH, stage and Karnofsky index, showed a clear distinction between the four risk categories low, low/intermediate, intermediate/high and high, with a median survival time of 43, 20, seven and four months, respectively. For the younger group the respective numbers were 144, 45, 19 and 11 months.

CONCLUSIONS

In a population-based NHL registry the elderly, predominately female patients, formed a larger proportion of the patient group than the one usually reported in the literature. In this population-based cohort inferior remission and overall survival rates were seen in the elderly. However, obtaining complete remission was beneficial for the prognosis of this disease in the elderly. By the application of the R.E.A.L. Classification important subgroups emerge.

Non-Hodgkin's lymphoma in the elderly. I. Pathologic features at presentation

The pathologic findings of 118 patients aged 70 years or older with non-Hodgkin's lymphoma (NHL) are reported. These patients formed 27.2% of 433 consecutive cases of NHL seen in a single institution over a 5-year period. Thirty-one of 433 NHL cases were histologically not classified, whereas the remaining 402 could be classified according to the International Working Formulation (WF) of NHL for clinical usage. Immunophenotypic analyses were carried out in 112 NHL cases; of this group 28 were NHL in elderly patients. Of the 95 elderly NHL that could be classified in the histologic categories of the WF 28 cases were in the low-grade, 41 in the intermediate-grade, and 26 in the high-grade categories. Eighty-one cases had diffuse histologic types and 14 had follicular/nodular histologic types. Thirty-five cases were of the G (diffuse large cell) + H (large cell, immunoblastic) categories. No significant differences in the prevalence of the different subtypes were observed among patients younger or older than 70 years. Immunohistologically, most NHL cases in the elderly expressed B-cell phenotype. Sixty-two NHL in the elderly were extranodal at presentation. The results of this study indicate that elderly patients form a relevant proportion of patients developing NHL and thereby present a very difficult management problem. The pathologic features of NHL in the elderly does not differ significantly from those of their younger counterparts, although an increase in diffuse versus follicular histologic patterns, and in extranodal versus nodal disease was observed with advancing age.

Vimentin immunostaining in fibroblastic reticulum cells within human reactive and neoplastic lymphoid follicles

We analyzed the distribution of fibroblastic reticulum cells (FRCs), stationary cells of lymphoid tissues, as visualized by the anti-vimentin (V9) monoclonal antibody in human reactive and neoplastic lymphoid follicles, by using immunoenzymatic and immunofluorescence methods on fixed and paraffin-embedded tissue sections from 37 lymphoid specimens with reactive disorders and 10 specimens with nodular/follicular non-Hodgkin's lymphomas (NHLs). The pattern of distribution of the vimentin-positive (VIM+) FRCs was compared with that of follicular dendritic reticulum cells (DRCs) as visualized by anti-S-100 protein antibody. Elongate VIM+ FRCs intimately attached to reticulum fibers were randomly distributed in the paracortical and interfollicular areas of lymph nodes, whereas they were recognized specifically in the mantle zones of the secondary follicles, mostly in the outer margins. Germinal centers were consistently devoid of VIM+ FRCs. Comparative analysis on serial sections as well as paired immunoperoxidase and double immunofluorescence studies demonstrated that there was a sharp difference between the patterns of intrafollicular distribution of VIM+ FRCs and S-100 protein-positive (S-100+) DRCs without juxtaposition, the FRCs being confined to the mantle zones. In the 10 nodular/follicular NHLs VIM+ FRCs could be observed in the thinned mantles of neoplastic nodules displaying a corona-like pattern that accentuated the boundaries of the nodules. The results of this study support the view that the intrafollicular distribution of VIM+ FRCs is specific for the mantle zone. The different microenvironmental organization within the follicles of VIM+ FRCs and S-100+ DRCs suggests that FRCs or at least VIM+ FRCs are stationary cells strictly related to the mantle zone microenvironment, where they may play a role in supposed sustentacular and immunologic functions similar to that of DRCs in the germinal center microenvironment.

Dendritic reticulum cell-related immunostaining for laminin in follicular and diffuse B-cell lymphomas

We performed a comparative immunohistocytochemical study of the distribution patterns of laminin and follicular dendritic reticulum cells (DRCs) within their follicular microenvironment in both nodular or diffuse B-cell non Hodgkin's lymphomas (NHLs). Twenty nine cases of immunophenotypically diagnosed B-cell NHLs (19 of follicular center cell origin-FCCL- and 10 of the diffuse well differentiated lymphocytic type-WDLL-) and five reactive lymph nodes with follicular hyperplasia were analyzed by immunoperoxidase and immunofluorescence techniques. Serial frozen sections and cytospin preparations were tested either with single antibodies anti laminin and DRC-1, or paired reagents in double labeling immunofluorescence. Our results indicated consistently that within both the reactive germinal centers and the neoplastic nodules of FCCL laminin immunostaining visualized a punctate-granular pattern apart from the linear vascular basement membrane positivity. Double immunofluorescence assay demonstrated that there was a close parallelism between this laminin staining pattern and DRC-1 distribution showing a well developed DRCs meshwork; in the diffuse tumour areas of both FCCL and WDLL, laminin immunoreactivity was found only in those cases in which nests of DRCs were observed. Double immunofluorescence studies performed on cytospin preparations demonstrated that the groups of cells containing DRC-1 positive cells, contained a positivity for laminin, although within the cell the staining for DRC-1 was intense and diffuse, while that for laminin was granular and more sparse. Our results suggested that these laminin and DRC-1 positive reactive sites may be present on the same cells. Since the reduction in number or loss of both DRCs and their related immunostaining for laminin within the microenvironment was consistently associated with a loss of nodularity by lymphoma cells, whereas nodularity in reactive and neoplastic conditions was associated with a rich DRCs meshwork and the related laminin immunostaining, a trapping function of DRCs exercised in the presence of laminin should be considered.

Conversion of high grade lymphoma tumor cell line to intermediate grade with TPA and bryostatin 1 as determined by polypeptide analysis on 2D gel electrophoresis

A high-resolution two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used for total cellular polypeptide mapping of two established lymphoma cell lines; MANCA, a Burkitt's line representing a high grade lymphoma (HGL) and WSU-NHL (nodular histiocytic lymphoma) representing an intermediate grade lymphoma (IGL). Gels were digitized and analysed with an image scanning computer using the Elsie 4 system. Polypeptide mapping revealed striking similarities in 1100 polypeptide spots in both types. However, three polypeptides were unique to HGL (Molecular mass/isoelectric point (Mr/PI): 39/4.4, 35/5.6, 33/4.8), and one to IGL (95/4.7). In order to investigate the kinetics of expression of these polypeptides, the two cell lines were treated with two protein kinase C (PKC) activators, tumour promoting 12-O tetradecanoylphorbol 13-acetate (TPA) and bryostatin 1. 2D-PAGE of the treated cells revealed that the HGL line loses its unique polypeptides and expresses a new one. The new polypeptide has the same Mr and PI as that unique to the untreated IGL (95/4.7). TPA or bryostatin 1 treatment of the IGL line for 72 h induced no significant changes. Our data show a unidirectional change from HGL to IGL, supporting the clinical notion that HGL is less differentiated than IGL. It also shows the similarity in the mode of action of bryostatin 1 and TPA in inducing these polypeptide changes.

Integrated expert systems and videodisc in surgical pathology: an overview

We present an overview of our 6-year experience in the design of expert systems for anatomic pathology. Our practical goal is to help practicing pathologists with learning, teaching, and the task of diagnosis by providing them with dynamic expert knowledge by means of a personal computer. This project could only be undertaken by first addressing a scientific goal: to characterize the problem-solving strategies that expert pathologists use in making a diagnosis and to state them in the logical terms of computer science. Our approach has been to build systems first for experimentation and then for use. The result of our work is an integrated computer-based approach that handles expert knowledge as formal relationships and morphologic images and that uses a number of logical strategies to provide multiple perspectives on diagnostic tasks. Configured as a pathologist's workstation, this approach can be expected to enhance the performance of trained general pathologists and pathologists in training. Lymph node pathology has been used as the prototype domain for this research, but care has been taken to seek a generalized authoring and inference structure that can be applied to other areas of pathology by changing the contents but not the structure itself. Excursions into various surgical pathology specialties suggest that the ways the system is constructed and exercised is fundamentally robust. Such computer-based expert systems can be expected to generate a new standard in the practice of pathology--based on the "gold standard" of classical morphology, but including the coordinated use of new methods from immunology and molecular biology in a multidisciplinary approach to diagnosis when these techniques are relevant. The benefits from this technology can be expected to be widespread with the evolution, refinement, and diffusion of these systems.

Imprint cytology of non-Hodgkin's lymphomas based on a study of 212 immunologically characterized cases: correlation of touch imprints with tissue sections

The classification of non-Hodgkin's lymphomas (NHLs) has been traditionally based on analysis of histologic sections and has been supplemented more recently by immunologic marker studies. It was the purpose of the present study to illustrate, side-by-side, sections and Romanowsky-stained imprints from the same surgical specimen from practically all categories of immunophenotyped NHLs, including rare and atypical variants that were difficult to classify from the histologic sections alone. Our results indicate that imprint cytology may reveal nuclear and cytoplasmic details not discernible in even the best tissue sections and that it may be selectively helpful in contributing to the classification of NHLs. Our results also show that the relative value of imprint cytology in the classification of malignant lymphomas varies greatly among categories. Specifically, we have found that imprints assist in three ways: the recognition of plasmacytoid features in small cell lymphocytic lymphomas, the recognition of plasmacytoid immunoblastic lymphoma, and the differentiation between NHLs which may be difficult to distinguish histologically. These include (1) small lymphocytic lymphoma versus lymphocytic lymphoma of intermediate differentiation, (2) true histiocytic malignancies versus large cell malignant lymphomas with abundant cytoplasm and/or phagocytosis, (3) anaplastic myeloma versus plasmacytoid immunoblastic lymphoma, (4) large noncleaved versus plasmacytoid immunoblastic lymphoma, (5) lymphoblastic lymphoma versus diffuse small cleaved cell lymphoma, and (6) lymphoblastic lymphoma versus small noncleaved cell lymphoma. Lymph node imprints are easy to prepare and readily interpretable by those experienced in the study of abnormal blood and bone marrow films. Their value as an ancillary methodology aimed at optimal accuracy in the classification of NHLs should be recognized.

Immunoglobulin and T cell receptor gene rearrangements and in situ immunophenotyping in lymphoproliferative disorders

We investigated for rearrangements of the immunoglobulin (Ig) heavy and light chain genes and of the T cell receptor gamma (TCR gamma) and beta (TCR beta) genes 45 biopsy samples from a variety of lymphoproliferative disorders. They were diagnosed histopathologically and immunophenotypically as non-Hodgkin's lymphomas (NHLs) of the B cell type (19 cases), NHLs of the T cell type (3 cases), NHLs of "undetermined" cell type (3 cases), atypical lymphoid proliferation (1 case) and AIDS-related lymphadenopathies with florid polyclonal follicular hyperplasia (19 cases). A monoclonal proliferation of B cells was shown by DNA analysis in all 19 B cell NHLs. In two immunohistologically determined T cell NHLs (both diagnosed as mycosis fungoides) the cells had rearrangements of TCR beta gene, whereas in the third case (lymphoblastic NHL) the cells had rearrangements of Ig heavy chain and TCR gamma and TCR beta genes. None of the B cell NHLs exhibited TCR gamma and TCR beta gene rearrangement bands. All the "undetermined" cell NHLs demonstrated rearrangements of Ig heavy chain gene associated with the germ line TCR gamma and TCR beta genes; in two cases light chain gene rearrangements were also found. The atypical lymphoid proliferation, in which the differential diagnosis was between a reactive or malignant process, and two out of 19 cases of florid polyclonal follicular hyperplasia showed a clonal B cell population by DNA analysis. This study indicates that there was a strong correlation between the rearrangements of specific genes and the immunophenotype of the NHL; moreover, DNA analysis of tissue biopsy specimens from phenotypically "undetermined" cell NHLs and from equivocal lymphoid proliferation using Ig and TCR gene probes yielded an answer in the cases analyzed. The significance of clonal B cell expansions found in two AIDS-related lymphadenopathies should be interpreted with caution.

Diagnostic significance of histiocyte-related markers in malignant histiocytosis and true histiocytic lymphoma

Interrelationships of immunologic and enzymatic markers of histiocytes have been studied in malignant neoplasms of histiocytic/monocytic origin and in differential diagnostically relevant, large cell non-Hodgkin's lymphomas. Cryostat sections required for demonstrating cell surface antigens by monoclonal antibodies are inadequate for studying cellular detail, enzymatic maturation by alpha-naphthyl acetate esterase (ANAE), and demonstrating the classical cytoplasmic markers of histiocytes like lysozyme, alpha-1-antitrypsin (AT), and alpha-1-antichymotrypsin (ACT). These markers have been compared in gently fixed and vacuum paraffin-embedded material. The reactivity for monoclonal anti-human monocyte 1 (Mo 1) has also been preserved by this method. Malignant histiocytosis (MH) is characterized by a heterogeneous cell population. The mature, ANAE-positive cells with macrophage morphology usually show a diffuse cytoplasmic positivity for AT and ACT. Lysozyme is moderately positive to negative in these cells, but it is more efficient than these markers in revealing smaller cells resembling monocytes by focal positivity in the cytoplasm. The expression of Factor XIIIa (F-XIIIa) is connected with the phagocytic activation of histiocytic cells. F-XIIIa positive cells usually form a minority of the neoplastic population in MH, but the large cytophagocytic marcophages are invariably positive. Reactive macrophages in large cell non-Hodgkin's lymphomas are characterized by a coexpression of ANAE, AT, ACT, lysozyme, F-XIIIa and Mo 1. Typical cases of true histiocytic lymphoma (THL) are made up of a homogeneous population showing the above mature, phagocytizing phenotype. In MH, Mo 1 and ANAE recognize different subpopulations. The reciprocal relation of these markers is an abnormal phenotypic feature. The results presented in this article prove the diagnostic value of ANAE and lysozyme in confirming the histiocytic differentiation of malignant cells. Monoclonal anti-human monocyte 1 is useful for identifying the immature component in MH. Factor XIIIa can be considered a functional marker of mature phagocytic histiocytes and an aid in the diagnosis of THL.

A clinico-pathological and prognostic analysis of non-Hodgkin lymphoma. A study of 203 patients

In a retrospective analysis of 203 patients with non-Hodgkin lymphoma (NHL) treated between 1975 and 1985, the relationship between pathology, clinical presentation and course, was studied, using the Kiel classification. This classification was a much better predictor of prognosis than clinical stage and within the different pathology groups there was no significant difference between the stages concerning the survival rate. In the group with low grade malignancy this latter was positively associated with nodular architecture, bone marrow involvement and complete or partial response to therapy. In the high grade group, the survival was positively correlated to complete remission, but no plateau was seen in the survival curve. All extranodal sites had poor survival. For both grades, age (greater than 60 years), systemic symptoms and biologic signs (Ann Arbor 'B' and 'b') were unfavorable prognostic factors.

T-cell lymphomas in adults: a clinicopathological study of eighteen cases

Eighteen cases of adult T-cell lymphoma have been studied with respect to clinical presentation, response to treatment, histology, enzyme histochemistry, immunocytochemistry, and gene rearrangement. Seven cases (39 per cent) presented at extra-nodal sites, and the age range was from 18 to 79. Treatment was with combination chemotherapy in most cases, and 11 of the 18 patients died within the three year follow-up period. The lymphomas were classified morphologically into six types; T-lymphoblastic lymphoma (TLL), angioimmunoblastic lymphadenopathy (AIL)-like T-cell lymphoma, T-zone lymphoma, pleomorphic mixed medium and large cell T-cell lymphoma (PMMLC), pleomorphic large cell T-cell lymphoma (PLC), and monomorphic large cell T-cell lymphoma (MLC). Enzyme histochemistry was found to be of limited value in the identification of T-cell lymphomas. Immunocytochemistry showed a degree of correlation between the immunological profile and morphology, with cases in the PLC and MLC groups showing limited expression of T-cell antigens. Re-arrangement of the beta chain of the T-cell receptor gene was detected in 12 of the 14 cases studied, and all showed germ-line immunoglobulin genes. The study emphasizes the varied morphological and clinical appearances of adult T-cell lymphoma.

Non-Hodgkin's lymphomas in the elderly: prospective studies with specifically devised chemotherapy regimens in 66 patients

The results of 2 consecutive and prospective trials with specifically devised chemotherapy regimens in elderly patients (pts) with non-Hodgkin's lymphoma (NHL) are reported. Between August 1979 and September 1984, 66 pts aged 70 or older (median 75 years) with NHL entered 2 consecutive trials, the former with single agent teniposide 100 mg/m2 i.v. weekly (41 pts), the latter with etoposide and prednimustine (E + P), 100 mg/m p.o. for 5 days every 21 days (25 pts). Forty-five pts were previously untreated, 21 previously treated. Forty-seven pts were of the intermediate and high grade groups according to the Working Formulation; 19 pts were of the low grade; 57 pts were stages III and IV, 9 pts were stages I and II. The median performance status was 70 (range 30-100). The objective response rate in the 66 evaluable pts is 53% with 38% CR; the 3-year overall, disease-free and CR survivals are 21, 12 and 40% respectively. The objective response rate in the 45 previously untreated pts is 58% with 42% CR; the 3-year overall, disease-free and CR survivals are 24, 16 and 58% respectively. The overall toxicity was mild. Severe toxicity (grade III and IV according to WHO criteria) was observed only in 16/498 courses (3.2%), with 1 toxic death (grade IV leucopenia). We experienced the usefulness of a properly orientated clinical approach to elderly pts with NHL. We suggest that a combination regimen like E + P, suitable for oral administration, may be safely employed in a large fraction of pts with NHL.

A morphologic study of childhood lymphoma of the undifferentiated type. The Pediatric Oncology Group experience

A retrospective analysis of 49 cases of undifferentiated non-Hodgkin's lymphoma, registered through the Pediatric Oncology Group's randomized clinical trials between 1976 and 1982, suggests that the histologic distinction between Burkitt's and non-Burkitt's tumor is clinicopathologically irrelevant in children. Patients with undifferentiated lymphoma were stratified morphologically into three subtypes: Burkitt's (B; 18 patients); non-Burkitt's (NB; 21 patients); and small noncleaved, not-otherwise-specified (NOS; 10 patients). Median age at presentation was 10 years for B; 12 years for NB; 6 years for NOS; and 10 years overall. Univariate analysis of clinical and laboratory data at presentation, yielded no significant differences between B, and NB patients. Complete remissions were obtained in 75% of the patients, and there were no significant differences in complete remission rate among the different morphologic subtypes of undifferentiated lymphoma. There were no significant differences in the estimated disease free survival between B, and NB patients. No morphologic parameters were identified that were predictive of prognosis.

A morphologic study of childhood lymphoma of the lymphoblastic type. The pediatric Oncology Group experience

For this study 227 non-Hodgkin's lymphomas, registered through the Pediatric Oncology Group clinical studies between 1976 and 1982, were morphologically subclassified into major histologic types and subtypes, and their histopathologic and clinical features were compared. These lymphomas were distributed primarily into only three of the recognized major histologic types: lymphoblastic (LB), 106 (47%); undifferentiated (DU), 49 (21%); and diffuse histiocytic (DH), 72 (32%). These patient groups were found to differ in several ways: the LB lymphomas contained most of the patients under two years of age; the LB lymphomas tended to present in higher clinical stages; the LB lymphomas tended to involve lymph node groups and the bone marrow more often than did the DU and DH lymphomas; and the DU lymphomas had a greater tendency for gastrointestinal tract and other major organ system involvement. The complete remission rate of 96%, for the LB lymphomas was better than for either the DU or the DH lymphomas. The disease-free survival of the LB lymphomas was significantly better than the DU group, but not the DH group. The LB were histologically divisible into three subtypes: convoluted (C), nonconvoluted (NC), and large cell variant (LCV). The C and NC subtypes preferentially involved the mediastinum and peripheral lymph nodes initially, while the LCV tended to involve the abdomen. However, none of the subtypes differed in clinical stage. The complete remission, and the disease-free survival rates between these subtypes were not statistically different.

Non-Hodgkin's lymphoma in the elderly. A retrospective clinicopathologic study of 50 patients

The pathologic and clinical findings of 50 patients aged 65 or older (median, 71.5 years) with non-Hodgkin's lymphomas (NHL) are reported. These patients formed 27% of all cases of NHL seen in a single institution over a 7-year period. Forty patients presented with nodal and 10 with extranodal NHL. According to the Ann Arbor system, 20 were clinical and/or pathologic Stages I and II, and 30 were Stages III and IV; of the 10 patients presenting with extranodal NHL, 8 were Stages I and II. Histologically, 84% of the cases were of the intermediate and high-grade groups according to the Working Formulation; diffuse histiocytic was the most frequent histotype (34%) according to the Rappaport classification. The pattern was diffuse in 94% of the cases. Five patients received no treatment; treatments were conservative (monochemotherapy and/or local radiotherapy) in 19 patients and aggressive (polychemotherapy and/or extended-field radiotherapy) in 26. Four patients of the latter group died of toxicity; 22 patients died of lymphoma and 13 of other causes; the other 11 (22%) patients are still alive. The overall median survival was 2.2 years. A significantly better survival was observed in patients with Stages I and II (P less than 0.025) and in those with intermediate grade (P less than 0.05) when compared with patients having Stages III and IV and high-grade histology, respectively. Apparently, no significant difference both in response and survival was found between the groups of patients which arbitrarily underwent conservative or aggressive treatments on the basis of their general conditions. Randomized clinical trials should be designed in order to draw more significant conclusions on the correct management of elderly patients with NHL.

Extranodal oral lymphoma. Part I. A morphologic and immunoperoxidase study of 34 cases

Thirty-four cases of oral lymphoma were classified by the Lukes-Collins system on the basis of morphology and immunoperoxidase staining. Ninety-seven percent of these were morphologically identified as B-cell neoplasms: 6% SCFCC, 9% LCFCC, 26% SNCFCC, 24% LNCFCC, 12% IBS, and 18% malignant plasma cell proliferations. Monoclonal immunoperoxidase staining for cytoplasmic immunoglobulin was positive in 41% of the cases overall, but 100% of the cases of immunoblastic sarcoma and malignant plasma cell lesions stained positively.

Morphological and immunohistochemical characteristics of T-cell malignant lymphomas in the west of Scotland

Sixteen cases of T-cell malignant lymphoma are described. They represent the experience of a single pathology department in recent years and serve to illustrate several of the reasons why recognition of T-cell differentiation is important in the classification of lymphomas.

Malignant histiocytosis complicating rheumatoid arthritis: report of four cases

Four patients with rheumatoid arthritis developed a similar type of lymphoreticular tumour. The morphology and immunocytochemical findings suggested that this was a form of malignant histiocytosis: there may be an important correlation between this tumour and rheumatoid arthritis.

Immunoblastic sarcoma of T- and B-cell types: morphologic description and comparison

Immunoblastic sarcoma (IBS) is a large cell lymphoma conceptually related to transformed T and B lymphocytes of the extrafollicular compartment of the immune system (immunoblasts). This light microscopic study of a series of 47 immunologically defined cases of IBS was undertaken in an attempt to define more precisely the morphologic features of the T- and B-cell subtypes. A remarkable morphologic spectrum characterized T-IBS (31 cases), which could be divided into two main groups: 1) tumors composed of varying mixtures of small, medium-sized, and large transformed cells; and 2) tumors with more homogeneous populations of medium-sized or large transformed cells. These cells, in all sizes, generally had abundant pale-staining cytoplasm, delicate nuclear membranes, finely dispersed chromatin, and one to several, small or medium-sized, prominent nucleoli. A distinctive background of small, irregular lymphocytes was frequently present. Plasmacytoid differentiation, seen most consistently as amphophilic staining of the cytoplasm, generally characterized B-IBS (16 cases). B-IBS similarly showed a morphologic spectrum that occurred in two main forms: 1) tumors consisting of a spectrum of transformed cells, with the smaller cells often showing the most striking plasmacytoid differentiation; and 2) tumors consisting predominantly of medium-sized to large transformed cells with varying degrees of plasmacytoid differentiation. With this constellation of features, all but two cases of T-IBS and one case of B-IBS were morphologically distinguishable.

Comparison of the working formulation of non-Hodgkin's lymphoma with the Rappaport, Kiel, and Lukes & Collins classifications. Translational value and prognostic significance based on review of 658 patients treated at a single institution

Six hundred fifty-eight cases of previously untreated non-Hodgkin's lymphoma seen between 1970 and 1979 at the Medical Department, the Finsen Institute, were the basis for a comparative study of the prognostic value of the Rappaport, Kiel, and Lukes & Collins classifications and the new translation system, the Working Formulation of Non-Hodgkin's Lymphoma. Each histopathologic system proved equally effective in separating patients into subgroups with a spectrum of prognoses ranging from a median survival of less than 1 year to greater than 7 years. The established classifications were compared with the Working Formulation in order to evaluate its translational value. The Working Formulation was more similar to the Rappaport and the Lukes & Collins systems than to the Kiel system, since 82%, 89%, and 75% of the cases, respectively, were translatable following the guidelines outlined in the National Cancer Institute (NCI)-sponsored study. Similarities among the four systems were demonstrated in lymphomas with follicular growth pattern, and in diffuse lymphomas composed of small mature appearing lymphocytes or small cleaved lymphocytes. Incongruity among the systems was more marked in lymphomas composed of large lymphoid cells or in lymphomas of mixed cellular composition. A comparison was performed for each classification against the Working Formulation. All such subdivided subsets were tested for prognostic heterogeneity and the following conclusions were reached: the diffuse poorly differentiated lymphocytic category of Rappaport was separated into two subgroups (malignant lymphoma [ML] small cleaved cell and ML lymphoblastic) with different prognoses (P = 0.01); the diffuse "histiocytic" lymphomas were prognostically homogeneous, since none of the newer systems were able to identify subpopulations with significantly different prognoses; the subtypes of the Kiel classification were prognostically homogeneous; the only weakness of the Lukes & Collins classification was the undefined cell subtype, encompassing two populations with different prognoses; and (5) the importance of follicular growth pattern was confirmed for small cleaved cell and mixed cell cytology, whereas large cell cytology implied a poor prognosis regardless of pattern. By the use of the Cox regression model it could be demonstrated that the Working Formulation can substitute any of the established classifications in terms of prognostic value.

Immunoblastic lymphoma involving the bone marrow in a patient with alpha chain disease. Clinical and immunoelectron microscopic study

A patient is reported who had disseminated immunoblastic proliferation that emerged during the course of alpha chain disease. This proliferation was characterized by overt marrow invasion together with osseous and neurologic manifestations. On immunoelectron microscopic study, the malignant immunoblasts displayed varying degrees of cytoplasmic maturation and constituted a morphologic spectrum of alpha-chain-synthesizing cells, ranging from immature blasts without endoplasmic reticulum development to relatively mature plasmablasts; alpha chain was not expressed at the surface of these cells. The general features of the overt malignant stage of alpha chain disease are reviewed in reference to this unusual case. The implications of the cellular findings are discussed with regard to the maturation stage of malignant immunoblasts.

Immunodeficiency and prognosis in patients with non-Hodgkin's lymphomas

Monocyte depleted blood lymphocyte subpopulations, their functions and relation to prognosis were studied in 68 untreated adult patients with non-Hodgkin's lymphomas classified according to the Kiel nomenclature. The median observation time was 48 months (range 41-60). The mean total blood lymphocyte and T (SRBC-rosetting) cell counts were significantly decreased as compared with age-matched controls (n = 57). Twenty-five per cent of the patients had a monoclonal blood B lymphocyte population. The spontaneous lymphocyte DNA synthesis, measured as incorporation of 14C-thymidine, was increased and the response to mitogen and antigen stimulation was decreased. Blood lymphocyte counts and functions before treatment were not related to the rates of remission or survival.

Cytosine arabinoside transport and metabolism in acute leukemias and T cell lymphoblastic lymphoma

Cytosine arabinoside (araC) has proven efficacy in acute myeloid leukemia (AML), but its place in the treatment of acute lymphoblastic leukemia (ALL) and T lymphoblastic lymphoma is uncertain. The therapeutic potential of araC has been assessed in patients with AML, ALL, and T lymphoblastic lymphoma by measuring the conversion of araC to its active metabolite, the 5'-triphosphate of araC (araCTP), in purified blasts from patients as well as in normal polymorphs and lymphocytes. In all leukemias, araCTP was the major intracellular metabolite of araC. The highest araCTP formation was in blasts from T lymphoblastic lymphoma, which formed threefold more nucleotide than myeloblasts, and in turn myeloblasts formed twofold more araCTP than lymphoblasts from ALL. The mean araCTP formation in myeloblasts was sixfold greater than polymorphs, but in contrast, lymphoblasts and lymphocytes formed low and similar amounts of this nucleotide. Reasons for the sixfold range in araCTP accumulation in the various leukemic blasts were studied. The mean size of myeloblasts was 35-70% larger than lymphoblasts when compared on the basis of protein or intracellular water content, but T lymphoblastic lymphoma blasts and lymphoblasts were the same size. Activities of deoxycytidine kinase, deoxycytidylate deaminase, and pyrimidine nucleoside monophosphate kinase were not different between any of the leukemic cell types. The number of nucleoside transport sites on blasts was estimated by measuring the equilibrium binding of [3H]nitrobenzylthioinosine (NBMPR), which binds with high affinity to the transporter. Scatchard analysis yielded mean values of 27,500 sites/cell for T lymphoblastic lymphoma blasts, 10,000 sites/cell for myeloblasts, and 2,300 sites/cell for lymphoblasts. Our previous work has shown that araC influx correlates with the maximum number of 3H-NBMPR binding sites in leukemic and normal white cells. A strong correlation was observed between the number of nucleoside transport sites per leukemic blast cell and the accumulation of intracellular araCTP from extracellular araC at 1 microM. Membrane transport of araC at the low concentrations (approximately 1 microM), which are achieved therapeutically, is a major rate-limiting step in its conversion to araCTP by leukemic blast cells. Myeloblasts form more araCTP than lymphoblasts because of both higher nucleoside transport capacity and larger cell size. The highest nucleoside transport capacity and largest conversion of araC to araCTP is in T lymphoblastic lymphoma, which suggests that araC may be effective in the treatment of this disease.

Classification of non-Hodgkin's lymphomas. Reproducibility of major classification systems. NCI non-Hodgkin's Classification Project Writing Committee

An international, multi-institutional, clinical, pathologic study of 1175 cases of non-Hodgkin's lymphoma sponsored by the National Cancer Institute has offered a unique opportunity to investigate issues of reproducibility and agreement in pathologic classification. Teams of experienced hematopathologists reviewed all 1175 cases, with the "experts" utilizing their own classification system and the experienced panelists utilizing all six of the histopathologic classification systems. The fact that 20% of the slides were randomly repeated for a second interpretation allowed assessment of the reproducibility of any one given pathologist. In addition, the agreement between and among pathologists was evaluated. Results of this retrospective study showed that both experts and panelists were able to identify follicular (nodular) or other indolent lymphomas with 95% probability of concurrence between initial and later interpretations. Moreover, individual pathologists agreed with others in identifying and classifying these follicular features with approximately 90% probability of agreement. The reproducibility for individual pathologists, based on the 20% of cases that were randomly repeated, varied from a probability 0.53 to 0.93. Comparisons of intersystem predictability demonstrated that no one system predicted for any of the other systems within any major degree of reliability. This inability to "translate" from one system to another is thought to be a reflection of the problems of both interpathologist agreement and intrapathologist reproducibility. Flaws in study design are discussed and the usage of the working formulation of non-Hodgkin's lymphomas, in addition to classification by traditional schemas, is strongly encouraged.

Immunological detection of covert leukaemic spread in mediastinal T-cell lymphoblastic lymphoma

A double immunofluorescence assay for terminal transferase (TdT) and surface membrane T-cell differentiation markers, defined by monoclonal antibodies, was used to analyse peripheral blood and bone marrow from patients with mediastinal T-cell lymphoma with clinically localized disease. In 2 patients, at diagnosis and during two subsequent relapses, cells with abnormal immunological phenotype were detected in low numbers in the peripheral blood, which contained no morphologically abnormal cells on any occasion. Bone marrow was uninvolved by immunological criteria on 3 of 4 examinations. The findings suggest that morphologically undectable T-lymphoblasts escape from the site of disease origin in the thymus in patients with lymphoblastic lymphoma, leading to "seeding" of sites such as bone marrow and central nervous system. Furthermore, the techniques described appear to be potentially very useful for the monitoring of lymphoblastic lymphoma patients for early prediction of disease relapse.

Stereological analysis of non-Hodgkins lymphomas

A detailed stereological analysis was carried out on 30 lymph nodes at 2 ultrastructural levels. They were classified as follows: 10 were reactive lymph nodes, 10 were of low-grade non-Hodgkins lymphomas and 10 were of high-grade non-Hodgkins lymphomas. The mean and median values and interquartile ranges of nuclear profile diameter, nuclear volume, volume of cytoplasm, cell volume and absolute number of ribosomes were recorded for each case. The model proved very efficient in establishing several significant differences between the highgrade and lowgrade lymphomas and between the highgrade lymphomas and reactive lymph nodes but did not discriminate between lowgrade lymphomas and reactive nodes, nor did it distinguish neoplastic cells from reactive cells in the neoplastic group. The significance of these findings is discussed.

Nuclear morphologic and morphometric analyses of large noncleaved cell and immunoblastic non-Hodgkin's lymphomas

Both morphologically and immunologically, non-Hodgkin's lymphoma (NHL) of the large cell type has been shown to be a heterogeneous category. However, the homogeneity of the nuclear parameters, particularly size and condensed chromatin organization, used to classify this subtype of NHL has not been investigated. In fact, objective morphologic techniques have not been systematically applied to verify the segregation of NHL on the basis of nuclear parameters, a concept common to all current classification systems. In this study morphometric image analysis was used to compare the nuclei in 20 specimens from NHLs of the large cell type with those in mantle zone and germinal center lymphocytes from lymph nodes with reactive hyperplasia. Results of the assessment of mean nuclear area in large cell lymphomas revealed that this class is also heterogeneous, with some of the specimens having a nuclear size in the upper range of that for normal small lymphocytes. In addition, in only a few of these specimens was the mean nuclear area within the range of that for fully transformed germinal center lymphocytes. The majority of large cell lymphomas have a nuclear size more characteristic of partially transformed lymphocytes in germinal centers. In addition to indicating inconsistencies in the current diagnostic criteria used in NHL classifications, the results indicate reasons for interobserver variations in clinicopathologic trials; the validity of nuclear size as a prognostic indicator and the biologic basis for classifying NHL as a reflection of normal lymphocyte transformation are also questioned. In terms of patient management, the classifications of NHL currently used require objective reappraisal.

Patterns of bone marrow involvement in chronic lymphocytic leukemia and small lymphocytic (well differentiated) non-Hodgkin's lymphoma. Its clinical significance in relation to their differential diagnosis and prognosis

Forty-eight patients with chronic lymphocytic leukemia (CLL), and 12 patients with small (well differentiated) lymphocytic lymphoma (WDL) were histologically evaluated for their pattern of bone marrow (BM) involvement. Four different types of BM infiltration were recognized: nodular (N), interstitial (I), nodular and interstitial (mixed) and diffuse (D). The pattern of BM involvement was compared with the clinical, laboratory, and survival status in all patients. The extent of the disease in CLL patients, was determined by the Rai and the International Workshop on CLL Staging Systems, while in WDL patients the Ann Arbor staging system was used. In the CLL group the N pattern was found in 8%, the I in 33%, the mixed in 31%, and the D in 27% of the patients. Based on the International Workshop on CLL Staging System, the I pattern of BM involvement was more frequently found in Stage A (56%), the mixed in Stage B (68%), and the D in Stage C disease (90%). All CLL patients with D pattern required treatment from the beginning, contrary to CLL patients with the other patterns, in whom therapy was required in less than 50%. Similarly, deaths were more common in the D pattern in whom therapy pattern than in the other patterns. In the WDL patients BM involvement was found in 4 of 12, (33%) and its pattern of positivity was always nodular, although most patients (10 of 12) had advanced disease. It is concluded that the frequency of BM involvement may contribute in the differential diagnosis of WDL from CLL. In addition, the pattern of BM infiltration correlates very well with the International Staging System for CLL, and the pattern of BM positivity in CLL patients also has prognostic significance.

A phase II trial of teniposide (VM 26) in advanced non-Hodgkin's lymphoma, with emphasis on the treatment of elderly patients

Fifty-four patients entered a phase II trial of teniposide (VM 26) in Stage III (35 patients) and stage IV (19 patients) non-Hodgkin's lymphoma (NHL) classified according to modified Rappaport system. The median age was 71 years (range, 19-85). Thirty-two patients were previously treated at least with combination chemotherapy and radiotherapy, whereas 22 were elderly (range, 70-85 years) untreated patients with a median Karnofsky score of 70. VM 26 was given by IV infusion at 100 mg/m2 weekly for at least 3 doses in "unfavorable" histologic subtypes, and for at least 6 to 9 doses in "favorable" subtypes, prior to the evaluation of response. The overall objective response rate was 43% in the 51 evaluable patients. The median duration of the 12 complete responses (CRs) was 7+ months (26+ to 2). According to the histology, VM 26 was very effective in the six patients with diffuse "histiocytic" (DH) subtype (four CRs, one partial response [PR]), and in the 8 patients with mycosis fungoides (MF) (two CRs, two PRs). Diffuse lymphocytic poorly differentiated and lymphoblastic NHL were less sensitive subtypes to VM 26. Among the 20 evaluable elderly patients a 50% objective response rate was obtained with five CRs. Four CRs and one PR were obtained in the five patients with DH subtype; no response was obtained in the only patient with MF. Toxicity, usually hematologic, was mild, even in elderly patients; neurotoxicity occurred in four instances. VM 26 seemed to be an effective and well-tolerated drug in advanced NHL; this drug should be further evaluated as first line chemotherapy in elderly (greater than or equal to 70 years) previously untreated patients with poor general conditions and DH histology.

NHL-3 protocol six-drug combination chemotherapy for non-hodgkin's lymphoma

Combination chemotherapy and radiotherapy (RT) were administered to 73 adults with non-Hodgkin's lymphoma (NHL). Ten cycles of the following drugs were given: intravenous Adriamycin (doxorubicin) (25 mg/m2), cyclophosphamide (700 mg/m2) and vincristine (1.5 mg/m2) on day 1; arabinosylcytosine (100 mg/m2) and methotrexate (10 mg/m2) on days 3 to 5; and oral prednisone (60 mg/m2) on days 1 to 5. Radiotherapy was given to resistant or initially bulky disease (2000 rad). Patients were also randomized to receive pseudomonas vaccine or no immunotherapy. Of 61 evaluable patients, 33 (54%) achieved a complete response (CR) and 18 (30%) a partial response (PR). Among 44 evaluable patients with diffuse histiocytic lymphoma (DHL), 22 (50%) had a CR, and 15 (34%) a PR. For 17 evaluable patients with nodular (4) and diffuse (11) mixed and poorly differentiated lymphocytic and diffuse "undifferentiated" (2) lymphomas, CR and PR rates were 65% and 18%, respectively. No statistically significant differences in response rate or duration and survival have been observed between the patients randomized to receive pseudomonas vaccine or no immunotherapy. Median follow-up time from start of treatment was 47.5 months. Median survival for all 73 patients (including inevaluables ) and for 52 DHL patients was 30.7 months. Poor prognostic features influencing survival included: female sex (P = 0.003), poor response to therapy (CR versus PR; P = 0.001), prior chemotherapy, (P = 0.01) and high levels of lactic dehydrogenase (P = 0.001). It can be concluded that this combination of cycle and phase-active agents is of similar efficacy to other reported regimens in inducing major responses and that it has the potential to prolong disease-free survival. The analysis of prognostic factors has been used to dissect poor prognostic categories that might require different modalities of treatment.

A clinicopathologic study in advanced non-Hodgkin's lymphomas treated with sequential non-cross-resistant regimens: comparison of the working formulation with the Rappaport and Kiel classifications

One-hundred and ninety-four adult patients with histologically proven stage III and IV non-Hodgkin's lymphomas, treated with CVP (cyclophosphamide, vincristine and prednisone) alternated with ABP (adriamycin, bleomycin and prednisone), were analyzed to test the validity of the clinicoprognostic correlation offered by the working formulation in comparison with the Rappaport and Kiel classifications. Actuarial overall survival at 5 yr showed a significant difference among the three prognostic subgroups of the working formulation (low grade, 53.3%; intermediate grade, 47.5%; high grade, 27.7%). Overall survival of favorable subgroups of the Rappaport and Kiel classifications was superior to that of unfavorable prognostic groups. The percentage of systemic symptoms and bulky disease increased in patients with low-grade compared to those with intermediate-grade and intermediate-to-high-grade malignancy. The achievement of complete remission was not related to any of the prognostic groups of the Working Formulation, and no difference could be detected within the various prognostic groups of the Rappaport and Kiel classifications. Within the diffuse histiocytic lymphomas of the Rappaport classification, two groups with a different prognostic outcome were evidenced by the working formulation (G, with an overall survival of 50%, and H, with an overall survival of 26.7% at 5 yr) and by the Kiel classification. The possibility of reporting results in the three different groups of the working formulation instead of two can be considered a step forward. Within the diffuse histiocytic histology, the working formulation allows separation, as does the Kiel classification, into two main different prognostic subgroups.

Studies on the pathology of non-Hodgkin's lymphoma of childhood. I. The role of routine histopathology as a prognostic factor. A report from the Children's Cancer Study Group

Between April 1977, and August 1980, the Children's Cancer Study Group (CCSG) conducted a clinical trial of childhood non-Hodgkin's lymphoma (NHL), randomizing 256 patients to one of two treatment regimens. A 4-drug regimen (regimen 1, modified cyclophosphamide, Oncorin [vincristine], methotrexate, prednisone [COMP] ) was compared with a 10-drug regimen (regimen 2, modified LSA2-L2). Using the Rappaport classification, the review pathologist diagnosed the 213 evaluable tissue specimens as follows: lymphoblastic (LC), 73; Burkitt's tumor (BT), 40; "undifferentiated" non-Burkitt's type (NB), 67; large cell or "histiocytic" lymphoma (HI), 29; and other types (OT), 4. Concurrence in classification between the review and institutional pathologists was poor when using the above four categories; however, concurrence was 88% between the review pathologist and other hematopathologists, and 99% when classifying the specimens as lymphoblastic or nonlymphoblastic. For patients with nonlocalized disease, this randomized controlled study demonstrated a new important correlation of histopathology with the effectiveness of treatment. When analyzed without stratification into lymphoblastic and nonlymphoblastic types, the two regimens showed identical relapse free survival (RFS) curves for patients with nonlocalized involvement. However, when patients were stratified according to histologic classification, regimen 2 was superior to regimen 1 for patients with lymphoblastic lymphoma, achieving 74% RFS at 30 months compared to 31% for regimen 1 (P = 0.001). Conversely, those with nonlymphoblastic types (BT, NB, HI) treated with regimen 1 had a 58% RFS at 30 months compared to 32% for those treated on regimen 2 (P = 0.01). This study demonstrates that proper, routine histopathologic classification of NHL is the best criterion for choice of therapy in children with nonlocalized involvement. As a result of this study, all patients with nonlocalized disease, diagnosed after August 1980, were no longer randomized but were assigned to the appropriate treatment regimen based on prospective review of histopathology.

Histological, epidemiological and clinical aspects of centroblastic-centrocytic lymphomas subdivided according to the "working formulation"

A group of 424 lymphomas diagnosed as centroblastic-centrocytic lymphomas at the Lymph Node Registry in Kiel was subdivided into small (S), mixed (M) and large (L) cell groups, according to the "working formulation" proposed in a National Cancer Institute sponsored study. Histological epidemiological and clinical parameters were studied. It was found that in group S a follicular growth pattern was most frequent and in group L a follicular and diffuse growth, while group M took an intermediate position. No statistically significant differences were found in respect to epidemiological factors or overall survival. However, in the first 6 years after the diagnosis the survival in group S was better than in group M, but thereafter a reversal occurred. Group L appeared to have the worst survival throughout. Growth pattern and sclerosis were found to be of limited influence on survival within the cytological groups.

Histiocytic sarcoma (true histiocytic lymphoma): a clinicopathological study of 20 cases

Large-cell non-Hodgkin's lymphomas (T- and B-immunoblastic, centroblastic and true histiocytic lymphomas) have a heterogeneous clinical course. In the present study the clinical and morphological data of 20 cases of histiocytic sarcoma (true histiocytic lymphoma) are presented. Diagnosis was supported by immunohistochemistry, cytochemistry, rosette assays and/or electron microscopy. Although the follow-up was relatively short (up to 144 months, mean 26 months), the clinical data differed clearly from the series of large-cell non-Hodgkin lymphomas, recorded in the literature. Differences were found in age distribution with a peak in the third decade, in organ involvement showing a preference for skin, gastrointestinal tract and bone, and in response to therapy. In general, histiocytic sarcoma appears to have a more favourable response to therapy and clinical course than the other large-cell lymphomas (T- and B-immunoblastic and centroblastic lymphomas). Moreover, preliminary observations in the group of histiocytic sarcomas suggested that the presence of lysozyme and/or 5-nucleotidase and the absence of alpha 1-antitrypsin in the cytoplasm is associated with a better response to therapy and favourable clinical course.

The heterogeneity of follicular center cell lymphomas. I. Cytohistologic, immunologic, and enzymehistochemical aspects

Histologic material from 44 patients with follicular center cell lymphomas with a follicular growth pattern was divided into five groups on the basis of the predominating neoplastic cell type(s), i.e., small centrocytes with occasional centroblasts (SCC), centrocytes and few (CBCC/A) or many (CBCC/B) centroblasts, small and large centrocytes (SLCC), and small and large centroblasts (SLCB). Histologic, immunologic, and enzymehistochemical parameters as observed in these groups were compared, and follow-up material and material obtained during staging procedures were studied. Immunologic and enzymehistochemical findings confirmed both the B-cell origin and the neoplastic nature of the lymphomas, but did not yield relevant differences between the various groups. The groups with a predominance of small centrocytes or of small centrocytes and centroblasts showed the most prominent follicular growth and early dissemination to bone marrow and spleen. Histologic transformation in these groups was characterized by an increase in the number of centroblasts and a more diffuse growth pattern. The groups composed of small and large centrocytes or centroblasts tended to a more diffuse growth and had later dissemination and no histological transformation.

Adult non-Hodgkin's lymphoma. Correlation of cell surface marker phenotype with prognosis, the new working formulation, and the Rappaport and Lukes-Collins histomorphologic schemes

The interrelationships between histomorphologic classification, cell surface marker phenotype and prognosis were prospectively studied in 130 adults with non-Hodgkin's lymphomas. Within each of the classification schemes used there were certain histologic variants that exhibited heterogeneity of cell lineage as well as those that were extremely uniform. Diffuse lymphomas with cell populations consisting of large cells, or mixtures of large and small cells were the most heterogeneous phenotypically and were most resistant to precise definition of immunologic cell lineage. The new Working Formulation for Clinical Usage likewise exhibited considerable heterogeneity of phenotype even within well defined histomorphologic categories. Two immunologic phenotypic variables that conferred a significant favorable prognosis were the expression of surface membrane immunoglobulin (B derivation) and the simultaneous expression of a membrane mu and delta immunoglobulin heavy chain. The results of this study suggest that cell surface marker phenotypic determinations have well defined and potentially useful correlations with histomorphologic classification schemes, and are useful in predicting biologic behavior and prognosis. It is suggested that a knowledge of both immunologic phenotype and histomorphologic characteristics is necessary in formulating therapeutic decisions.

Lectin binding patterns in diffuse large cell lymphoma

The staining reaction of a panel of lectins in paraffin embedded lymph node specimens of diffuse large cell lymphoma was studied in relation to survival. In 47 of 49 patients, varying degrees of lectin binding were observed with Ricinus communis agglutinin (RCA), crude extract of Arachis hypogaea (c-PNA), Concanavalin ensiformis A (Con A), Triticum vulgaris A (WGA) and Phaseolus vulgaris A (PHA). Binding was either absent or only minimal with Pisum sativum A (PSA) and Lens culinaris A (LCA). Two categories of binding were observed: cell surface and cytoplasmic. Cell surface binding was seen in tumor cells, while cytoplasmic binding was observed in macrophage-histiocytes. Varying numbers of tumor cells were stained with RCA, WGA, c-PNA or PHA; but with Con A virtually no tumor cells were stained. Stromal macrophage-histiocytes were stained with RCA, WGA, or Con A in all but one case, frequently with all three lectins; c-PNA binding macrophage-histiocytes were absent in one third of the cases. With PHA the staining of stromal macrophage-histiocytes was extremely rare. Tumor cells that stained with RCA but not with c-PNA were observed in 9 of 15 patients who survived more than 2 years after diagnosis. In all 15 long-term survivors, stromal macrophage-histiocytes were positive for c-PNA. Tumor cells that reacted with c-PNA but not with RCA were seen in five patients who survived less than two years. All 16 patients whose tumors lacked c-PNA binding stromal macrophage-histiocytes in the presence of RCA binding macrophage-histiocytes were short-term survivors. These observations suggest the heterogeneity of stromal macrophage-histiocytes as well as that of tumor cells. Furthermore, the variation of lectin binding might be useful in assessing prognosis.

A new working formulation of non-Hodgkin's lymphomas. A retrospective study of the new NCI classification proposal in comparison to the Rappaport and Kiel classifications

Two hundred thirty cases of malignant non-Hodgkin's lymphomas were reclassified in a retrospective study according to the New Working Formulation for Clinical Usage of the NCI as compared to the Rappaport and Kiel classifications. The reproducibility for the individual schemes this study was 81% (Rappaport), 79% (Kiel), and 85% (New Working Formulation). In keeping with the results of the NCI international study, all lymphomas were subdivided into 3 prognostic groups: (1) low-grade malignancy (6.0 years median survival); (2) intermediate-grade malignancy (3.5 years median survival); and (3) high-grade malignancy (1.4 years median survival). The NCI-proposed New Working Formulation for Clinical Usage is thus recommended as practical and unprejudicing classification scheme for general application; however, its usefulness as tool for translating one classification scheme into another appears limited.