Non-Hodgkin's lymphoma of the gastrointestinal tract: a population-based analysis of incidence, geographic distribution, clinicopathologic presentation features, and prognosis. Danish Lymphoma Study Group.

PURPOSE: To evaluate incidence, time trends, geographic distribution, clinicopathologic presentation features, and prognostic factors for survival and relapse in gastrointestinal (GI) non-Hodgkin's lymphomas (NHLs). PATIENTS AND METHODS: Over a 9-year period (1983 to 1991), 2,446 new NHL cases were recorded in a Danish population-based NHL registry (Danish Lymphoma Study Group [LYFO]). Of these, 306 (12.5%) were GI NHL (175 gastric, 109 intestinal, and 22 both sites). LYFO registry data were used for incidence rate (IR) assessment, and time-trend and geographic distribution analysis. Relative risk (RR) values for survival and relapse were identified by multivariate analysis. RESULTS: The mean annual, age-standardized IRs for gastric and intestinal NHL were 0.71/10(5) and 0.48/10(5) per year, respectively. Age-specific IRs for both localizations showed an exponential increase as a function of age. Time-trend analysis for the period 1983 to 1991 showed stable IRs for both localizations. Intestinal NHL was more frequent in males (male-to-female ratio, 2.0 v 1.3), and had a higher occurrence of disseminated disease, constitutional symptoms, high-grade histology, and T-cell phenotype (10% v 2%). Gastric NHL had more low-grade cases (38% v 19%), and almost all were of the mucosa-associated lymphoid tissue (MALT) type. The cause-specific 5-year survival rate was 63% for gastric NHL and 49% for intestinal NHL. The Musshoff staging system was an excellent discriminator between truly localized (stage I and II1) and disseminated cases (stage II2 to IV), particularly for gastric NHL, for which no survival difference was found between surgically and conservatively stage localized cases. CONCLUSION: (1) No increase in the incidence of GI NHL was found over a 9-year observation period; (2) nonrandom spatial distribution of new GI NHL cases was observed; (3) factors that significantly increased the risk of death in gastric cases were presence of B symptoms (RR = 3.3), clinical stage is more than II1 (RR = 3.0), age more than 72 years (RR = 2.4), and elevated serum lactate dehydrogenase (s-LDH) level (RR = 2.0); and factors that increased the risk of death in intestinal cases were presence of B symptoms (RR = 3.2), age more than 58 years (RR = 2.8), and clinical stage more than I (RR = 2.1); (4) factors that significantly increased the risk of relapse in gastric cases were male sex and no radiotherapy in primary treatment; and in intestinal cases were T-cell phenotype and no surgery in primary treatment; (5) surgical staging, as opposed to thorough noninvasive staging, did not improve staging accuracy and final outcome in localized gastric NHL.

Long-term survival and development of secondary malignancies in patients with acute myeloid leukemia treated with aclarubicin or daunorubicin plus cytosine arabinoside followed by intensive consolidation chemotherapy in a Danish national phase III trial. Danish Society of Haematology Study Group on AML.

In 1991 we reported the results from a prospective randomised phase 3 trial comparing 7 days continuous infusion of cytosine arabinoside (ara-C) combined with either daunorubicin (DNR) or aclarubicin (ACR) as direct i.v. injection for 3 days as induction chemotherapy (CT) for patients with de novo acute myeloid leukemia (AML) followed by early intensive consolidation CT with two alternating cycles of high-dose ara-C and two cycles of amsacrine plus etoposide, and finally 3 days of daunomycin plus 7 days of ara-C as administered for induction of remission. A total of 174 patients with de novo AML in the age group 17-65 years were included. The patients have now been followed till death or for at least 7 years, and an evaluation of the long-term survival and the risk of developing secondary neoplasms has been made. The overall survival rate 5-years after diagnosis was 23%, and after 10 years 19%. No difference was found between the two treatment regimens in overall survival or disease-free survival (DFS). For the subgroup of 99 patients who achieved complete remission after one or two induction courses, 5- and 10-year survival rates were 35% and 31% respectively, with the highest survival rates in the age group 17-39 years (57% at 5 years) as compared with 27% in patients aged 40-60 years (P= 0.007). Seven secondary neoplasms were diagnosed simultaneously with or after the diagnosis of AML indicating a standardized incidence ratio (SIR) of 3.41, (95% CI: 1.60-7.26). In three cases the secondary neoplasms were diagnosed simultaneously with the AML diagnosis and were for that reason completely unrelated to the chemotherapy administered for AML, as the psammomatous meningeoma diagnosed after only 8 months. The remaining three neoplasms which developed subsequently did not significantly exceed the expected number, with a SIR = 1.46 (0.47-4.57). Thus, no increased risk of solid tumors causally related to the intensive chemotherapy for de novo AML was observed. However, a generally increased risk of solid tumors in patients diagnosed simultaneously with the AML diagnosis seems likely. Over 20% of the patients were alive and in complete remission 5 years after the AML diagnosis, and they have a high probability of surviving the next 5-year period.

Clinicopathological features and prognostic factors in extranodal non-Hodgkin lymphomas. Danish LYFO Study Group.

In a Danish population-based non-Hodgkin lymphoma (NHL) registry, 1257 newly diagnosed NHL cases were registered over a 5-year period. Of these, 463 (37%) were extranodal. The gastrointestinal tract was the most common site of extranodal involvement (30% of the cases). Histologically, 44% of all extranodal NHL cases had high-grade, 17% intermediate and 27% low-grade features, while 12% were unclassified. The most common histological subtype (Kiel) was the centroblastic diffuse (23% of cases). 50% of all extranodal NHL were localised (stage IE or IIE) and 27% had B symptoms. Site-specific features included a strong age-correlation for thyroid and testes lymphoma (greater than 50 years) and a high prevalence of female cases in thyroid and salivary glands lymphomas (M/F 0.14 and 0.30, respectively). Overall 7-year survival for extranodal NHL was 46% (median 4.9 years). Poor prognosis patients could be identified by the presence of one or more of the following presentation characteristics: age greater than 65 years, B symptoms, high-grade histology, disseminated disease, elevated s-IgA and hyperuricaemia. Relative risk values ranged from 2.1 for age and B symptoms to 1.7 for hyperuricaemia.

In B-cell chronic lymphocytic leukaemia chromosome 17 abnormalities and not trisomy 12 are the single most important cytogenetic abnormalities for the prognosis: a cytogenetic and immunophenotypic study of 480 unselected newly diagnosed patients.

Of 560 consecutive, newly diagnosed untreated patients with B CLL submitted for chromosome study, G-banded karyotypes could be obtained in 480 cases (86%). Of these, 345 (72%) had normal karyotypes and 135 (28%) had clonal chromosome abnormalities: trisomy 12 (+12) was found in 40 cases, 20 as +12 alone (+12single), 20 as +12 with additional abnormalities (+12complex). Other frequent findings included abnormalities of 14q, chromosome 17, 13q and 6q. The immunophenotype was typical for CLL in 358 patients (CD5+, Slg(weak), mainly FMC7-) and atypical for CLL in 122 patients (25%) (CD5-, or Slg(strong) or FMC7+). Chromosome abnormalities were found significantly more often in patients with atypical (48%) than in patients with typical CLL phenotype (22%) (P < 0.00005). Also +12complex, 14q+, del6q, and abnormalities of chromosome 17 were significantly more frequent in patients with atypical CLL phenotype, whereas +12single was found equally often in patients with typical and atypical CLL phenotype. The cytomorphology of most of the +12 patients was that of classical CLL irrespective of phenotype. In univariate survival analysis the following cytogenetic findings were significantly correlated to a poor prognosis: chromosome 17 abnormalities, 14q+, an abnormal karyotype, +12complex, more than one cytogenetic event, and the relative number of abnormal mitoses. In multivariate survival analysis chromosome 17 abnormalities were the only cytogenetic findings with independent prognostic value irrespective of immunophenotype. We conclude that in patients with typical CLL immunophenotype, chromosome abnormalities are somewhat less frequent at the time of diagnosis than hitherto believed. +12single is compatible with classical CLL, and has no prognostic influence whereas chromosome 17 abnormalities signify a poor prognosis. In patients with an atypical CLL immunophenotype, chromosome abnormalities including +12complex, 14q+, del 6q and chromosome 17 are found in about 50% of the patients, and in particular chromosome 17 abnormalities suggest a poor prognosis.

Clinicopathological features, survival and prognostic factors of primary central nervous system lymphomas: trends in incidence of primary central nervous system lymphomas and primary malignant brain tumors in a well-defined geographical area. Population-based data from the Danish Lymphoma Registry, LYFO, and the Danish Cancer Registry.

It has been claimed that Primary Central Nervous System Lymphomas (PCNSL), a rare neoplasm accounting for only a small fraction of malignant brain tumors and extranodal non-Hodgkin lymphomas (NHL), occur with increasing frequency in immunologically normal as well as in immunocompromised individuals. In an attempt to characterize the clinicopathological features, outcome and prognostic factors of PCNSL we here report our experience in a large unselected series of patients from a well-defined region. In addition, we present data on trends in incidence of PCNSL and primary malignant brain tumors in a well-defined geographical area. In a Danish population-based NHL registry (LYFO) representing a population of 2.7 million all new cases of NHL were registered during the approximate 11-year period from 1st January 1983 to 31st May 1994. Incidence data of primary malignant tumors of the brain and central nervous system in western Denmark for the period 1971-1990 have been obtained from the Danish Cancer Registry. During the approximate 11-year period 3124 new cases of NHL were registered. Of these, 1152 (37%) were extranodal and 48 were non-AIDS related PCNSL accounting for 4.2% of extranodal NHL and 1.5% of all NHL, respectively. The average annual incidence rate of non-AIDS related PCNSL during the period was 1.56 cases per million population (age range: 15-85 yrs, median: 62 yrs, M/F ratio: 1). In a 23-year period there was no trend towards an increasing incidence of non-AIDS related PCNSL in a well-defined population. PCNSL accounted for 1.7% of all primary malignant brain tumors. Incidence of primary malignant brain tumors was stable, except for age ranges over 70 years. However, diagnostic artifacts might be responsible for this apparent increase. Histologically, 85% were high grade. Using the Kiel classification centroblastic diffuse (60%) and immunoblastic lymphoma (13%) were the most common subtypes. Forty-three patients had B-cell lymphoma and no T-cell lymphoma was detected. Forty-seven cases were diagnosed pre mortem. Treatment included surgical resection (26 patients), whole brain irradiation (WBRT) (43 patients) and chemotherapy (28 patients). Median survival for those receiving either WBRT or WBRT and chemotherapy was 8 months and 20 months, respectively (p = 0.78). Overall survival was 53%, 38% and 26% at 1, 2 and 5 years. Cox-regression analysis identified only one factor having independent impact on survival in PCNSL: performances score > or = 2 (p < 0.001, RR = 5.8).

Incidence, presenting features and prognosis of low-grade B-cell non-Hodgkin's lymphomas. Population-based data from a Danish lymphoma registry.

During the period January 1983 to January 1988 1597 newly diagnosed cases of non-Hodgkin's lymphoma (NHL) were included in a Western Danish population-based NHL registry. Of these, 31% (N = 496) were low-grade NHL (LG-NHL) consisting of (Kiel): 9% lymphocytic (LY), 27% lymphoplasmacytic/-cytoid (IC), 53% follicular centroblastic/-centrocytic (CB/CCf) and 11% unclassifiable low-grade. LG-NHL (age range: 26-94 yrs, median: 64 yrs; M/F ratio: 0.8) had an age-standardised incidence rate (IR) of 2.7/10(5)/yr. Age-specific IR's showed an age-related exponential rise in all subtypes except for CB/CCf. Compared with the intermediate (IG)- and high-grade (HG) group, LG-NHL had more female cases (M/F ratio: 0.79 vs. 1.2; p = 0.0002), a higher frequency of stage III-IV disease (66% vs. 53%; p < 0.00005) and of bone marrow involvement (39% vs. 19%; p < 0.00005). A later revision of all IC cases (N = 132) distinguished 79 non-polymorphic (ICnp) from 25 polymorphic (ICp) cases; 28 cases were differently classified. In 34 LG-NHL patients histologic transformation was verified: CB/CCf to CB diffuse (22 pts) and LY to immunoblastic or CB type (6 pts). The 7-yr survival for LG-NHL was 63% (IG: 48%, HG: 38%; p < 0.00005). A Cox-regression analysis identified the following adverse prognostic factors for survival in LG-NHL: age > 50 with a relative risk (RR) of 3.2, hepatic involvement (RR = 2.1), elevated s-LDH (RR = 1.9), B-symptoms (RR = 1.8) and IC histology (ICnp+ICp) (RR = 1.7).(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome for patients with leukemia, multiple myeloma and lymphoma who relapse after high dose therapy and autologous stem cell support.

Relapses after autologous transplantation are a serious clinical problem in patients with haematological diseases. The decision making for handling of such patients is difficult and the aim of this retrospective analysis of posttransplant relapses was 1) to obtain information of practical importance for the management of future relapses and 2) to evaluate the basis for clinical phase I-II trials of salvage therapy combined with biological modifiers. Included in the study were 283 patients with acute leukemia, multiple myeloma and malignant lymphoma who relapsed after autologous transplantations during a five year period from 1989 to 1994. Chemo- and radiotherapy was given to 229 patients after relapse or due to progressive disease and the response evaluated after 90 days. Fifty four patients (24%) obtained a complete remission and 44 patients (19%) partial responses. The overall median survival from relapse was 5 months. In the group given salvage treatment the median survival was 7 months and in the 54 patients who obtained remission the median survival was 15 months. So far 6 of 14 patients in continuous complete remission have a remission time after relapse longer than the time in remission after transplantation. Survival after relapse depended upon the time from transplantation to relapse, primary disease and if salvage therapy was given. In conclusion posttransplant relapses can be treated but the strategy has to be evaluated in future clinical trials.

Otological manifestations of Wegener's granulomatosis.

The otological manifestations of Wegener's granulomatosis were studied in 13 patients; diagnosis was confirmed histologically in 10, and in 1 patient periarteritis nodosa presented similar appearances. One patient had destruction of the external ear, and several had refractory otitis externa, usually associated with otitis media: 3 patients had serous otitis media, 4 had purulent otitis media of a fairly mild course, while 6 had otitis media of a fulminant and long-lasting course, accompanied in 5 cases by cranial nerve palsy and in 2 by widespread destruction. Most patients had major sensory hearing loss. Two had short-lasting anacusis during exacerbation of the pulmonary lesions. Often, otological manifestations were the initial signs of the disease. It is important to bear this diagnosis in mind in cases of long-lasting and atypical inflammations and in the presence of peculiar constellations of symptoms from several different organ systems.

Late nervous system disorders in cured malignant lymphoma: a clinical and neuropathological study.

A 53-year-old woman was treated for and cured of low grade malignant lymphoma, localized to the neck, by irradiation and chemotherapy. One year later she developed signs of damage to the spinal cord with slight paraparesis of the lower extremities, which remained stationary for seven years. Then, new and rapidly progressive central and peripheral neurological symptoms developed. About one year later the patient died. At autopsy a malignant glioma of the right temporal lobe and radiation damage to the spinal cord were found. Lymphocytic infiltrations in the peripheral nerves and muscles of the lower extremities were also seen. A severe neurogenic atrophy was present but no relapse of malignant lymphoma was found. Depressed immune defense is suggested to be the cause of the pathological changes of the nervous system in this case. The inflammation of the peripheral nerves might be due to activation of a latent virus infection.

Wegener's granulomatosis. Long-term results of treatment.

Seventeen patients with Wegener's granulomatosis are presented. The very complex clinical features are outlined. A recently suggested new classification (ELK-classification) is applied. Fourteen patients were treated with cytotoxic agents and steroids, 12 of these receiving 6-mercaptopurine. Of the ten patients still alive, eight are in remission with treatment withdrawn in three cases. The duration of the treatment is discussed. The results are largely satisfactory, but the course of the disease is still capricious. Progression to a higher step in the ELK-classification has been observed in several cases and a number of serious sequelae to the disease are recorded. The initial symptoms of Wegener's granulomatosis are varied and uncharacteristic, and it is important to bear this disease in mind when patients with a long course of apparently trivial infections or peculiar constellations of symptoms from several organs are encountered. Repeated biopsies from the respiratory tract are important in order to establish the diagnosis, but treatment should not be delayed in cases where only a tentative diagnosis can be made on the basis of a reasonably typical clinical picture, even with a negative histological response.

[Autologous bone marrow transplantation in children with malignant diseases. Bone marrow harvest and procedure-related toxicity]. / Autolog knoglemarvstransplantation hos børn med maligne sygdomme. Knoglemarvshøst og procedurerelateret toksicitet.

The aim of this paper was to present the results of bone marrow harvest followed by cryopreservation in 22 children with various malignant diseases, and the clinical course of autologous bone marrow transplantation (ABMT) performed in 10 children (three with acute lymphoblastic leukemia (ALL), three with acute myeloblastic leukemia (AML) and four neuroblastoma stage IV (NB)). In 20/22 children the harvested bone marrow contained a sufficient number of granulocyte-macrophage-colonyforming units (GM-CFU) for later marrow reinfusion. Hematological reconstitution was obtained in all 10 children who underwent ABMT. No child died of toxicity. The median time to neutrophil count > 0.5 x 10(9)/l, thrombocyte count > 50 x 10(9)/l and to discharge from hospital were 34, 49 and 29 days respectively. Five children are alive with no evidence of active disease 11-21 months after ABMT. Five children have suffered relapse and have died. It was concluded that sufficient amounts of precursor bone marrow cells may be harvested in children during a pause in cystostatic therapy. The acute toxicity of ABMT in children with malignant diseases was only moderate.

[Non-Hodgkin lymphoma in the elderly]. / Non-Hodgkin's lymfom hos aeldre.

Within a seven year period, 1597 newly diagnosed cases of non-Hodgkins lymphoma (NHL) were included in a Danish population-based NHL-register. Of these, 602 (38%) were aged 70 or older (age range 70-94, median: 76.8) and represented the population defined as "elderly" patients in the present study. Their average annual incidence rate was 35.7/10(5), as compared to 6.6/10(5) for patients aged < 70 (overall annual incidence: 9.5/105). Localised cases (stage I and II) and extranodal manifestations were more frequent among elderly patients. The most common sites of extranodal involvement were stomach (21% of all extranodal cases) and bone marrow (16%). Histologically, follicular centroblastic/centrocytic cases were found to be less frequent (p < 0.01) in elderly patients as compared to their younger counterparts (< 70 years), who on the other hand had a lower occurrence of diffuse centroblastic cases (p < 0.01). Overall seven year survival for the elderly patient population was 35% (median: 1.7 years), and for patients aged < 70 it was 57%. This difference persisted after correction for apparently NHL-unrelated deaths (52% vs. 66% respectively, p < 0.0001). The following poor prognostic factors for elderly patients were identified by multivariate analysis: hepatic involvement, presence of B-symptoms, high-grade histology and elevated s-LDH. The corresponding relative risk values were respectively 2.4, 2.2, 1.9 and 1.6.

[Autologous bone marrow transplantation in malignant blood diseases]. / Autolog knoglemarvstransplantation ved maligne blodsygdomme.

The authors present the organisation and preliminary experience with a comprehensive autologous bone marrow transplantation (ABMT) program in patients with malignant blood diseases. The procedure involves harvesting of bone marrow from patients in complete remission, purification of mononuclear cells and cryopreservation of these at -196 degrees C. After bone marrow cultures show that a sufficient number of hemopoietic progenitor cells (CFU-GM) are present in the marrow to reconstitute the patient, he/she is conditioned with chemo- (busulphan/cyclophosphamide (Bu + Cy)) or chemo/radiotherapy (total body radiation/cyclophosphamide (TBI + Cy)) in doses equal to those commonly used in allogeneic BMT. From February 1988 to July 1990 bone marrow (BM) was harvested from 24 patients. The median yield of mononuclear cells (MNC) was 1.2 x 10(8)/kg body weight (range 0.55-3.7). After buffy coat preparation, density gradient centrifugation, cryopreservation and thawing out, 0.60 x 10(8) MNC/kg (0.18-3.3) corresponding to 9.3 x 10(4) CFU-GM/kg (2.28-144) could be recovered. Twelve patients have received transplants, five with AML (after Bu + Cy conditioning), six with lymphoblastic lymphoma and one with Hodgkin's disease (with TBI + Cy conditioning). The median number of days to obtain greater than 1.0 x 10(9) leucocytes/l, greater than 0.5 x 10(9) neutrophils/l, greater than 50 x 10(9) thrombocytes/l and last requirement for erythrocyte transfusion were 21 (12-49), 28 (10-60), 55 (21-270) and 55 (12-129) days, respectively. Four patients had sepsis and the median duration of hospitalization was 39 (22-58) days. The most severe complications were seen in the AML patients, two of whom died during the posttransplant period (one of septicemia, one of thrombocytopenic bleeding).(ABSTRACT TRUNCATED AT 250 WORDS)

[Primary cerebral non-Hodgkin's lymphomas and primary malignant brain tumors in a well-defined geographical area. Population-based data from the registry of non-Hodgkin's lymphoma in western Denmark, LYFO and the cancer registry, Kraeftens Bekaempelse]. / Primaere cerebrale non-Hodgkins lymfomer og primaere maligne hjernetumorer i et veldefineret geografisk område. Populationsbaserede data fra det vestdanske non-Hodgkins lymfom-register, LYFO, og Cancerregisteret, Kraeftens Bekaempelse.

In a Danish population-based non-Hodgkin's lymphoma (NHL) registry (LYFO) representing a population of 2.7 million all new cases of NHL were registered from 1st January 1983 to 31st May 1994. Incidence data of primary malignant tumours of the brain and central nervous system in western Denmark for the period 1971-1990 have been obtained from the Danish Cancer Registry. During the approximate 11-year period 3124 new cases of NHL were registered. Of these, 1152 (37%) were extranodal and 48 were non-AIDS related primary central nervous system lymphomas (PCNSL) accounting for 4.2% of extranodal NHL and 1.5% of all NHL, respectively. The average annual incidence rate of non-AIDS related PCNSL during the period was 1.56 cases per million population (age range: 15-85 yrs, median: 62 yrs, M/F ratio: 1). In a 23-year period there was no trend towards an increasing incidence of non-AIDS related PCNSL in a well-defined population. PCNSL accounted for 1.7% of all primary malignant brain tumours. Incidence of primary malignant brain tumours was stable, except for age ranges over 70 years. Histologically, 85% were high grade, centroblastic diffuse (60%) and immunoblastic lymphoma (13%) (Kiel classification). No T-cell lymphomas were detected. Treatment included surgical resection, whole brain irradiation (WBRT) and chemotherapy. Median survival for those receiving either WBRT or WBRT and chemotherapy was eight months and 20 months, respectively (p = 0.78). Overall survival was 53%, 38% and 26% at one, two and five years. Cox-regression analysis identified only one factor having independent impact on survival in performance score > or = 2 (PCNSL p < 0.001, RR = 5.8).

Gastric lymphomas. Clinical features, treatment and prognosis.

A retrospective analysis of 48 patients with primary, gastric lymphoma was performed. The clinical features, early symptoms and signs were found to be similar to cases of gastric carcinoma. Often surgery was necessary to confirm diagnosis. The treatment modalities surgery, radiation therapy and chemotherapy are discussed. The prognosis for this limited group of patients was a 5-year survival rate of 62 per cent, and a 10-year survival rate of 48 per cent (crude survival). Survival data from comparable series are presented.

The clinical usefulness of serum copper determinations in Hodgkin's disease. A retrospective study of 241 patients from 1963-1973.

Serum copper determinations were routinely performed in 141 men and 100 women with histologically verified Hodgkin's disease, admitted to the Radium Centre for Jutland over a 10-year-period from January 1, 1963, to January 1, 1973. The previously described variations in serum copper with the activity of the disease, increasing with progression and decreasing with improvement, were amply substantiated. Furthermore, the present study showed that the serum copper value at the first admission, before treatment, is statistically significantly correlated to the stage of the disease and consequently probably to the amount of tumor tissue. In men there was also a statistically significant correlation of se Cu to the histologic grade of the bioptic material (classification according to Lukes 1966). In women the correlation was blurred by the effect on serum copper of estrogen, mainly from contraceptive pills and pregnancy. The serum copper is regularly reduced to within normal limits at complete remission; thus, it is proposed that this parameter be included in the criteria for complete remission.

Risk factors for central nervous system involvement in non-Hodgkins-lymphoma--a multivariate analysis.

A consecutive cohort of patients with NHL was examined to identify the factors predictive of CNS-involvement with Cox's proportional hazards model in a multivariate analysis. Twenty-seven cases of CNS-involvement were found among 498 patients with NHL. Only 3 of 96 patients with low-grade lymphomas had CNS involvement, all occurring after transformation into high-grade lymphoma. In univariate analysis of 402 patients with intermediate or high-grade lymphoma, lymphoblastic histology (including Burkitt's lymphoma), age <35 years, B-symptoms, stage IV disease, testis involvement and bone marrow involvement were found to be statistically significant risk factors. Lymphoblastic histology was found to be strongly correlated to age younger than 35 years. In the multivariate analysis only lymphoblastic histology, stage IV disease and B-symptoms were found to be significantly associated with CNS involvement. It is concluded that CNS prophylaxis should be considered in all patients with lymphoblastic histology and in patients with stage IV B lymphomas other than those of low-grade types.