Primary central nervous system T-cell lymphoma. Case report

Primary peripheral T-cell central nervous system lymphoma

BACKGROUND

Primary peripheral T-cell central nervous system lymphoma (PCNSL) is a rare, aggressive tumor that arises in the craniospinal axis and has an increased risk in individuals who are immunocompromised. This lesion often mimics other benign and malignant processes on radiographic imaging, leading to misdiagnosis and delays in treatment. We present a case of a patient with a history of Sjögren's syndrome and progressive neurologic symptoms who underwent craniotomy for diagnosis.

CASE DESCRIPTION

A 61-year-old woman with a history of Sjögren's syndrome, progressive aphasia, left facial droop, and right-sided paresthesias for 4 months presented for evaluation and management. An enhancing, infiltrative lesion in the left frontal lobe with underlying vasogenic edema was appreciated and suggestive of a primary or metastatic neoplasm. The patient underwent an open biopsy for further evaluation of the lesion. Extensive histopathologic evaluation revealed a diagnosis of T-cell PCNSL. The patient was started on induction methotrexate and temozolomide followed by consolidative radiotherapy.

CONCLUSION

Autoimmune conditions are a risk factor for T-cell PCNSL development. T-cell PCNSL has radiographic and gross histologic features that are consistent with a broad differential, including gliomas and inflammatory processes. Prompt diagnosis and extensive histopathological evaluation is essential to ensure appropriate treatment.

Primary and secondary central nervous system mature T- and NK-cell lymphomas

Primary central nervous system (CNS) mature T- and NK-cell lymphomas are rare, only comprising 2% to 3% of all primary CNS lymphomas. Among them, peripheral T-cell lymphoma, not otherwise specified, anaplastic large cell lymphoma (ALCL), and extranodal NK/T-cell lymphoma (ENKTL) are the commonly reported histological subtypes. Secondary CNS T-cell lymphoma generally affects about 5% of patients with T- or NK-cell lymphoma, with some exceptions. Acute and lymphomatous subtypes of adult T-cell leukemia/lymphoma (ATLL) have high risk of CNS progression, may affect up to 20% of patients; ALK-positive ALCL with extranodal involvement >1 also has high risk of CNS progression. However, the impact and the optimal methodology of CNS prophylaxis remain unclear in systemic T-cell lymphomas. There are little data on the treatment strategy of primary and secondary CNS T-cell lymphoma. Treatment strategy derived from B-cell CNS primary lymphoma is generally used; this includes induction therapy with high-dose methotrexate-based regimens, followed by high-dose chemotherapy with autologous stem cell transplant in fit patients. There are unmet needs for patients who are not fit for intensive chemotherapy. The prognosis after CNS progression in T-cell lymphoma is dismal with the median overall survival of less than 1 year. New agents targeting T-cell lymphomas are emerging and should be tested in patients with mature T- and NK-cell lymphoma who suffer from CNS involvement.

Primary Cerebral Lymphoma: A Retrospective Study in 22 Immunocompetent Patients

Aims and background

Primary CNS lymphomas are uncommon tumors in immunocompetent patients. We describe the radiological features that should orient towards performing a biopsy and analyze the results in our series of patients.

Methods

We reviewed 22 immunocompetent patients with primary central nervous system lymphoma admitted in our Institute between 1977 and 1997. The follow-up period ranged from 2 months (patient deceased) to 69 months. Fourteen patients underwent surgical removal of the tumor and the remainder a biopsy. All patients received radiotherapy and 8 patients radiotherapy plus chemotherapy.

Results

Two of the 14 patients treated by surgical removal of the tumor died. There was no mortality related to biopsy procedures. Patients treated with radiotherapy had 1-year, 2-year and 5-year survival rates of 66%, 41.6% and 16.6%, compared to 87.5%, 62.5% and 50%, respectively, for patients who received radiotherapy and chemotherapy.

Conclusions

At present, there is no definite treatment for these highly malignant brain tumors. The most favorable results seem related to biopsy followed by radiotherapy plus chemotherapy versus surgical removal, which is related to a high risk of severe postoperative deficit for both the deep location and infiltrating nature of these lesions.

Linfoma del sistema nervoso centrale in corso di AIDS

Il linfoma primitivo cerebrale (LPC) è la più comune delle neoplasie opportunistiche del SNC in pazienti AIDS, seguito dal linfoma di Kaposi e dai gliomi, e spesso rappresenta la patologia rivelatrice della condizione di immunodeficienza acquisita.

L'incidenza dei LPC è in costante aumento nelle ultime due decadi. Attualmente rappresentano il 6,6–15,4% di tutti i tumori cerebrali primitivi contro il 3,3% registrato prima del 1978. Nei pazienti AIDS, ha una frequenza compresa fra il 3% ed il 10%. Si tratta, peraltro, di una patologia ancora relativamente rara costituendo solo lo 0,7–0,9% di tutti i linfomi.

I LPC si localizzano in prevalenza in regione sopratentoriale (90%) specialmente nella sostanza grigia periventricolare e nella sostanza bianca; la localizzazione in fossa cranica posteriore è stimata intorno al 10%. Nel LPC l'interessamento leptomeningeo non è comune riscontrandosi in circa il 12% dei casi; più raro il coinvolgimento durale, rarissimo (circa 1%) il coinvolgimento del midollo spinale. Viceversa il linfoma secondario tende ad invadere la dura madre e le leptomeningi.

Il LPC in corso di AIDS si manifesta in forma multifocale fra il 50 ed il 75%.

Dal 1991 è stata documentata una quasi costante associazione del virus di Ebstein-Barr (EBV) con il LPC il che ha indotto a considerare la possibilità di usare l'EBV come un marker diagnostico di tale patologia.

La costante presenza del EBV nel LPC in immunodepressi è in contrasto con quanto visto negli immunocompetenti ove l'associazione è modesta.

Ad una valutazione macroscopica il LPC si manifesta come massa nodulare con consistenza molto variabile da friabile a solida e superficie granulare. La lesione è frequentemente circondata da edema, comunemente diffonde alla leptomeninge e alle regioni subpiali. È multifocale nel 11–50% dei pazienti immunocompetenti e nel 41–81% dei pazienti AIDS nei quali peraltro l'incidenza di multifocalità può raggiungere il 100%.

All'analisi istologica il LPC mostra strati uniformi di cellule neoplastiche, strettamente stipate; il processo di infiltrazione si diffonde ben oltre i margini macroscopici della lesione. Necrosi ed emorragie sono molto più frequenti nei pazienti immunocompromessi.

Neuroradiologicamente le lesioni risultano tipicamente iperdense alla TC e questo aspetto è attribuito ad un alto rapporto nucleo-citoplasma ed ad un elevata cellularità fittamente stipata. Dopo mdc praticamente tutti i LPC mostrano impregnazione la cui intensità è peraltro variabile e talora così debole e indefinita da non essere apprezzata se non utilizzando appropriate finestre.

In RM nelle immagini T1 la lesione è tipicamente da ipo- ad isointensa relativamente alla sostanza grigia e produce un effetto massa modesto rispetto alle sue dimensioni.

Nei primi riferimenti della letteratura tali lesioni erano descritte quasi uniformemente iperintense in T2. Più recentemente, e probabilmente in rapporto ad un affinamento del software che ha consentito una maggiore evidenza di fini dettagli, le lesioni si documentano prevalentemente iso-ipointense alla sostanza grigia in T2, aspetto che, come alla TC, riflette l'alto rapporto nucleo- citoplasma e l'elevata cellularità fittamente stipata.

Nella popolazione non AIDS il LPC mostra quasi costantemente alla RM un impregnazione dopo mdc che risulta omogeneo nei 2/3 dei casi.

Nella popolazione AIDS il LPC mostra impregnazione nel 100% dei casi che risulta disomogeneo nel 54% dei casi, con un pattern anulare nel 46% ed uno irregolare nell '8%.

Uno degli aspetti caratteristici del LPC è la tendenza a diffondere lungo l'ependima, le meningi o entrambe. Questa dtffusione è documentata in percentuali variabili che raggiungono il 75% e si attestano al 28% per la contiguità con la superficie ependimale e 1′8% per la contiguità con la meninge.

The selective cytotoxic anti-cancer properties and proteomic analysis of Trigonella Foenum-Graecum

BACKGROUND

There are a number of dietary components that may prove useful in the prevention and treatment of cancer. In some cultures, fenugreek seeds are used to treat cancer. The current study focuses on the anticancer properties and proteomic profiles of fenugreek seeds, and is prompted by the clinical profile of a case of primary CNS T cell lymphoma that responded to fenugreek treatment and resulted in tumor regression.

METHOD

Various normal and cancer cell lines were exposed to fenugreek extract at differing concentrations (100 μg/ml, 200 μg/ml and 300 μg/ml) and at different time points (0, 24, 48, 72 and 96 hrs). Protein fingerprints of fenugreek grain/seed types, obtained from four different geographical regions, were analyzed by proteomic expression profiles.

RESULTS

We observed selective cytotoxic effects of fenugreek extract in vitro to a panel of cancer cell lines, including T-cell lymphoma. Additionally, the cluster analysis of proteomics data showed that the protein profile of the particular fenugreek used by the patient is significantly different from three other regional subtypes of fenugreek extract.

CONCLUSION

The in vitro effect of fenugreek as a substance with significant cytotoxicity to cancer cells points to the potential usefulness of fenugreek in the prevention and treatment of cancer.

Primary central nervous system lymphoma in Korea: comparison of B- and T-cell lymphomas

The great majority of primary central nervous system lymphoma (PCNSL) is known to be of B-lineage, with T-cell PCNSL (T-PCNSL) accounting for <5%. We report an unusually high incidence of T-cell lymphoma among the PCNSLs originated in a large general-care hospital in the metropolitan Seoul area. PCNSLs (n = 42) accrued from April 1995 through June 2001 were reviewed for histologic and clinical features, and immunohistochemical staining was done for CD3, CD20, CD4, CD8, Bcl-6, and CD10. Clonal rearrangements of the TCR-gamma and IgH genes were studied with semi-nested PCR in all seven cases of T-PCNSL and seven of 35 B-cell PCNSL (B-PCNSL). Formalin-fixed, paraffin-embedded specimens were used in all these studies. By immunohistochemical staining and molecular studies, seven cases (16.7%) were diagnosed as T-PCNSL, each displaying clonal rearrangement of the TCR-gamma gene, and 35 (83.3%) as B-PCNSL. Radiologically, T-PCNSL was significantly correlated with the superficial and subcortical lobar location (p <0.001), solitary mass formation (p = 0.001), presence of rim enhancement (p <0.001), and peritumoral edema (p = 0.029). Involvement of cerebrospinal fluid was observed only in B-PCNSL (n = 17) but not in T-PCNSL (p = 0.010). Histologically, T-PCNSL was characterized by a population of mixed predominantly small- and occasionally medium-sized cells (p <0.001), which were loosely scattered without forming a solid mass (p = 0.024), and perivascular infiltration was frequent (p = 0.007), in contrast to predominantly large cells of B-PCNSL, i.e., diffuse large B-cell lymphoma (DLBCL), in which the cells tended to aggregate to form monomorphous sheets (p = 0.024). In T-PCNSL, staining for CD8 was positive in five, including one with coexpression of CD4, and two were negative for CD4 and CD8. Of 24 DLBCLs tested, the pattern of Bcl-6+ tumor cells was diffusely dense, similar to that of the germinal center in nine cases (37.5%), with coexpression of CD10 in three of the nine cases. T-PCNSL accounted for 16.7% of the PCNSLs; thus, in Korea it may not be as rare as previously known. The T-PCNSL presented with certain clinical and pathologic features that were distinct from B-PCNSL and displayed preponderance of CD8 expression. DLBCL of the germinal center B-cell derivation defined by bcl-6 expression comprised 37.5% of DLBCL of the brain.

Primary central nervous system cytotoxic/suppressor T-cell lymphoma: report of a unique case and review of the literature

Peripheral T-cell lymphoma primary to the central nervous system is a rare occurrence. The authors report a case of an 89-year-old woman who presented with a 3-month history of worsening confusion and recent onset of headache, nausea and vomiting, and upper limb tremors. Computed tomography and magnetic resonance imaging examinations demonstrated a 4.5-cm solitary brain mass in the right basal ganglia with compression along the ventricular system. No other lesion was found in the patient. Histologic and immunohistochemical studies of a stereotactic biopsy of the mass showed a T-cell lymphoproliferative lesion positive for CD3, CD8, CD57, and T-cell intracellular antigen 1 and negative for CD4, CD56, CD30, anaplastic lymphoma kinase, and CD20. A monoclonal T-cell receptor-gamma gene rearrangement was detected by polymerase chain reaction analysis of genomic DNA isolated from paraffin-embedded tumor tissue sections. These findings were consistent with peripheral T-cell lymphoma of cytotoxic/suppressor phenotype, resembling the phenotype of T-cell large granular cell leukemia. To the authors' best knowledge, this represents the first reported case of primary brain T-cell lymphoma with a cytotoxic/suppressor immunophenotype. A brief review of the literature of primary brain T-cell lymphoma is also presented.

Intraocular lymphoma: a series of 14 patients with clinicopathological features and treatment outcomes

AIMS

To assess the clinical features, pathology, mortality (systemic outcome) and ocular complications (visual outcome) of a cohort of patients treated for intraocular lymphoma.

METHODS

Retrospective case analysis of medical records and review of pathology of a consecutive series of patients presenting with intraocular lymphoma in Melbourne over 11 years between 1990 and 2000. Categorical factors influencing survival were examined by the Kaplan-Meier estimator and groups compared with the log rank test.

RESULTS

A total of 14 patients were included. The median age of onset of symptoms was 62.5 years. Most were male (64%) and had bilateral eye involvement (64%). The commonest presentation was vitritis in 12 patients, with a median delay of 4 months before diagnosis. In all, 10 patients had B-cell lymphoma, three patients T-cell lymphoma and one null-cell. Four patients had prior systemic lymphoma. Eight patients had primary central nervous system non-Hodgkin's lymphoma (PCNSL). Treatment included combined radiation to the eye and chemotherapy in 10 patients. Complications of radiotherapy included cataract in five (50%), dry eyes in four (40%), punctate keratopathy in two (20%), radiation retinopathy in two (20%), and optic atrophy in one (10%). A total of 11 patients died of lymphoma (79%). One has residual ocular disease, while two have survived for more than 5 years from initial presentation. Although currently disease free, one of these has a poor visual outcome with acuity less than 6/60 secondary to ocular complications of treatment.

CONCLUSIONS

Our study had 29% with prior systemic lymphoma, 57% associated with PCNSL and 14% with intraocular disease only. Overall survival is low (21%) and relapses common in those surviving beyond 12 months. Visual outcome in survivors is very poor due, in large part, to significant complications from radiotherapy.

Primary Ki-1 lymphoma in the central nervous system

Large cell anaplastic malignant lymphoma with Ki-1 (CD30) antigen is a new entity among human non-Hodgkin's malignant lymphomas according Updated Kiel Classification and is also a very rare subtype in primary central nervous system (CNS) malignant lymphomas. The precise clinical characteristics and the significance of Ki-1 antigen have yet to be clarified. The authors herein report a case of Ki-1 positive primary T-cell CNS malignant lymphoma. A 49-year-old man presented with multiple mass lesions in the brain on MRI. Immunohistochemical investigations of biopsy specimens from the superior medullary velum revealed a large cell anaplastic T-cell lymphoma positive for Ki-1 antigen. After administering extensive chemo-radiotherapy, the patient has survived for more than 42 months after the onset of symptoms.

Primary T-cell lymphoma of the brain in children: a case report and literature review

Described here are the clinical features and results of treatment in a 10-year-old Saudi Arabian girl with primary T-cell lymphoma of the central nervous system. At presentation the patient had nystagmus and ataxia. The diagnosis was established by tissue biopsy obtained from the cerebellum. Therapy included cranio-spinal irradiation and combination chemotherapy of a systemic high dose of methotrexate, cytosine, arabinoside, and L-asparaginase. Remission was obtained easily but was interrupted by a local intracranial relapse 57 months after diagnosis (37 months after cessation of therapy; at present the patient is still alive and receiving palliative treatment). This report is warranted because of the rarity of this condition in children.

Increased levels of CSF soluble CD27 in patients with primary central nervous system lymphoma

The aim of this study is to determine the diagnostic value of cerebrospinal fluid (CSF) soluble CD27 (sCD27) as a tumor marker for primary central nervous system lymphoma (PCNSL). We examined sCD27 levels in CSF obtained from various types of brain tumor patients. Forty-two patients were studied (including 12 PCNSL patients) who had not received any therapy for their tumors. In all PCNSL cases, CSF sCD27 levels were more than 15 U/ml (median 84.5 U/ml, range 17-484 U/ml) and in other brain tumor cases, CSF sCD27 levels were all less than 15 U/ml. Our data suggest that CSF sCD27 levels are useful to distinguish PCNSL from other brain tumors.

Primary central nervous system lymphoma of T-cell origin: description of two cases and review of the literature

Primary lymphomas of the central nervous system (PLCNS) of T-cell lineage are unusual. It has been suggested that T-cell PLCNS, compared to those of B-cell origin, present some differences in relation to age of presentation, gender, location of the tumor and survival. We describe two cases with T-cell PLCNS and review 22 parenchymatous T-cell PLCNS reported in the English literature. Age, gender and survival of the whole series of 24 T-cell PLCNS did not differ from that reported in large series of PLCNS where the great majority were of B-cell origin. In contrast, a location in the posterior fossa was found in 54% of T-cell PLCNS, whereas this location ranged from 12 go 29% in series of, mostly B-cell, PLCNS. T-cell PLCNS had a higher frequency (33%) of the histologic low grade small lymphocytic lymphoma than B-cell PLCNS (5%). Analysis of six T-cell PLCNS long-term survivors showed that half of them had low grade lymphomas. We conclude that T-cell PLCNS do not differ from those of B-cell origin in age of presentation or gender, but they have a preference to develop in the posterior fossa and a higher frequency of low grade histology which would probably explain the longer survival in some patients.

Primary cerebral non-Hodgkin's lymphoma (PCNSL): a review of new trends in management

Primary central nervous system lymphoma (PCNSL) is a rare tumor but it is rising in incidence in both AIDS and non AIDS populations. It is a non-Hodgkin's lymphoma that usually presents itself as a brain tumor, but leptomeninges, eyes and also spinal cord are frequently affected. The management of PCNSL patients has evolved in the last years. The role of surgery has been restricted for diagnosis only because the exeresis of the tumor is ineffective owing to its multifocal and infiltrative nature. Therefore, stereotactic biopsy is the way of choice for documenting the diagnosis. The standard treatment was radiotherapy started after diagnosis and followed by chemotherapy at recurrence. PCNSL is radiosensitive and chemosensitive: about 70% of patients respond to one or other of these treatment modalities but usually PCNSL recurs locally after radiotherapy. More recently the inclusion of high doses ARA-C and Methotrexate delivered prior radiotherapy have shown significant high responses and prolonged survivals.

Primary Ki-1-positive T-cell lymphoma of the brain--an aggressive subtype of lymphoma: case report and review of the literature

BACKGROUND

By detection of the Ki-1 antigen, Stein (1985) defined a new entity of anaplastic large cell lymphoma [24]. Apart from our case, only four further cases of Ki-1 positive primary central nervous system lymphoma (PCNSL) have been reported in the literature to date.

CASE REPORT

A 63-year-old man presented with two frontal and parietal mass lesions and one ring lesion on computed tomography scan. Clinically, no evidence of brain metastases or abscesses could be found. Immunohistochemical investigations of biopsy specimens revealed a large cell anaplastic T-cell lymphoma positive to Ki-1 antigen. In spite of all therapeutic efforts, the patient died less than 3 months after the onset of symptoms.

DISCUSSION

In all cases the clinical course was very rapid, suggesting that Ki-1 positive PCNSL might form an aggressive subtype of lymphomas. Since the radiologic appearance was atypical and clinical diagnosis was not possible, diagnostic biopsy for immunohistochemical diagnosis should be performed.

Primary T-cell lymphoma of the cerebellum. A case report

Most primary CNS non-Hodgkin lymphomas are of B-cell lineage. Only a very few immunocytochemically well documented cases of T-cell lymphomas have been reported. We report a case of a high malignant T-cell lymphoma localized primarily to the vermis of the cerebellum and compare the characteristics of the clinicopathological presentation with those of B-cell lymphomas as well as with the other T-cell lymphomas reported.

Primary central nervous system T-cell lymphoma with a predominant CD8 immunophenotype

BACKGROUND

Primary T-cell lymphomas of the central nervous system are uncommon neoplasms.

METHODS

A case of a primary central nervous system T-cell lymphoma in a 66-year-old female who died 8 months after surgery is described. The biopsy specimen was evaluated by routine histology, immunohistochemistry, flow cytometry, and Southern blotting/DNA hybridization.

RESULTS

The neoplasm was composed of pleomorphic medium and large cells. Virtually all of the neoplastic cells reacted with antibodies to CD3, CD5, and CD8. Multiple rearranged bands were detected with the T-cell receptor beta-chain gene probe.

CONCLUSION

To the authors' knowledge, this is the first description of a primary central nervous system T-cell lymphoma composed of a predominant population of CD8-expressing T cells, and the first case confirmed by Southern blotting/DNA hybridization.

Pathology with clinical correlations of primary central nervous system non-Hodgkin's lymphoma. The Massachusetts General Hospital experience 1958-1989

BACKGROUND

Primary central nervous system non-Hodgkin's lymphoma (NHL-CNS) is an enigmatic disease of uncertain origin. At the Massachusetts General Hospital, 104 patients with NHL-CNS were seen from 1958 through 1989. An impression of changes in the frequency of diagnosis, character of the tumors, and therapy for this disease prompted this study of the pathologic features, clinical data, and natural history of this tumor in these 104 patients.

METHODS

Histologic slides (neurosurgical specimens and autopsy tissues) were available for 99 patients. The tumors were classified by the Working Formulation classification. Immunostaining data and all clinical data were retrieved from the relevant offices and hospital charts.

RESULTS

Primary central nervous system non-Hodgkin's lymphoma tripled in frequency (5.66 cases per year in 1978-89 versus 1.75 cases per year in 1958-77) and now represents 6.6% of all primary brain neoplasms (versus 3.3% before 1978; chi 2 = 17.52, P < 0.01). For the 99 tumors histologically classified, 89% were high grade. Intermediate grade lymphomas, once the second most common subtype, have disappeared since 1983. All tumors had diffuse architecture; 77% (including all 11 patients with acquired immune deficiency syndrome) were large cell subtypes. Two cases were intravascular lymphoma. With one exception, all of the 41 tumors evaluated were B-cell types; 32 of 40 had monotypic surface immunoglobulin. There was 1 T-cell lymphoma. Of 64 tumor recurrences, 29 were at the initially defined site; 12 were in the leptomeninges, 29 were in other sites in the neuraxis, and 8 were in systemic sites. Systemic metastases have not occurred since 1984. Median survival for the 68 patients who survived after diagnostic surgery and for whom follow-up information could be obtained was 19 months; 9 months for those with high grade tumors and 30.5 months for those with intermediate grade tumors. This difference was not significant (P = 0.13). A separate set of seven patients had focal tumorlike lymphoid infiltrates composed of benign-appearing lymphocytes, which were associated with good long term survival. The differential histologic diagnosis of NHL-CNS was occasionally difficult, and the spectrum of this differential was broader than generally stated.

CONCLUSIONS

Primary central nervous system non-Hodgkin's lymphoma has increased in frequency even in nonimunocompromised patient populations. This increase has been accompanied by the disappearance of intermediate grade histologic types, suggesting a fundamental shift in the biology of the neoplasms. The introduction of chemotherapeutic regimens appears to have altered the natural history such that systemic metastases outside the central nervous system no longer occur, and there are now some long term survivors of this formerly uniformly fatal disease.

Non-Hodgkin lymphomas of the central nervous system. Clinico-pathologic and immunohistochemical study of 147 cases

We report on data gathered from five European centres regarding 147 primary non-Hodgkin Lymphomas (NHLs) of the Central Nervous System (CNS) in HIV-negative patients. The results lead us to make the following considerations: i) there has been a significant and progressive increase in the frequency of observation of this pathology during the course of the last two decades; ii) the pathology lacks specific characteristic symptoms; iii) the radiological profile, as observed by CAT and/or MNR, most frequently corresponds to an isodense or slightly hyperdense lesion which has clear margins and is capable of assuming the contrast medium homogeneously; iv) the tumour most often has a single supratentorial localisation; v) high grade B-cell lymphomas account for 66% of the observations, low grade B-cell varieties being relatively rare and cases of T-cell derivation exceptional (6/147); vi) immunohistochemistry allows the differential diagnoses with respect to primitive or secondary non-lymphoid tumours, and provides confirmation of the histogenetic assessment made on morphological grounds; vii) the course of the disease is not significantly influenced by the histotype, the phenotype, the number of lesions present or the chemotherapy regimen, but rather by the employment of combined surgery and radio- or radiochemotherapy. This study represents the largest series of CNS NHLs so far reported, and as such, provides precise clinico-pathological indications which were only partially obtainable from the relatively small previously published series. Some concluding remarks are made as to the genesis of CNS NHLs, along with some practical suggestions for reaching a better understanding of their complex biology.

Primary T-cell malignant lymphoma of the central nervous system. Histological, immunohistochemical and ultrastructural study of a case

Most primary malignant lymphomas (ML) of the central nervous system (CNS) are derived from B-cells, whereas T-malignant lymphomas (T-ML) primarily arising in the CNS are extremely rare. We report on a patient with a primary T-ML of the CNS localised in the posterior fossa. On the basis of histological, ultrastructural and immunohistochemical studies, this tumour was classified as a pleomorphic T-ML, medium and large cell type with peripheral helper/inducer T-cell phenotype (CD 1-, CD 2+, CD 3+, CD 5+, CD 7-, CD 4+, CD 8-, CD 19-, CD 22-, UCHL 1+/CD 45 RO, L 26-/CD 20, LN 1-/CDW75, LN 2-/CD 74, MB 2-). Furthermore, the positivity of the markers CD 25 and HLA-DR on many medium-sized and large lymphoma cells suggests activation of these cells. The nuclear marker of proliferative activity Ki-67 was expressed in some large cells, whereas the natural killer cell-related markers CD 16 and Leu 7/CD 57 did not react with lymphoma cells. This study emphasises the value of extensive immunohistochemical investigations on frozen and paraffin sections in order to identify and characterize the T-cell malignancies, particularly in their rare CNS location.

Primary central nervous system lymphoma

Primary central nervous system lymphomas (PCNSL) are uncommon neoplasms accounting for less than 2% of brain tumours. Their incidence appears to be increasing across a wide age range, in both immunocompetent and immunosuppressed populations. Particular risk groups include those with congenital and acquired immunodeficiencies and transplant recipients. The spread of the AIDS epidemic has seen large numbers of complicating PCNSL develop. Epstein-Barr virus infection appears to play a role in the development of these lymphomas in the immunosuppressed population. The aetiology of these tumours in the immunocompetent is uncertain. Their tendency to remain within the nervous system is not well understood but may be a function of CNS binding molecules carried by lymphocytes. Clinically PCNSL may present with a wide variety of signs and symptoms and has a capacity to mimic many other neurological conditions. Radiologically they appear as hyperdense homogenous deposits in subcortical white matter. Although most lesions are intermediate or high grade B cell lymphomas, T cell lymphomas are being recognised with increasing frequency. Immunohistochemistry and genotypic analysis have an important role in accurately characterising PCNSL, particularly in stereotactic biopsies. Involvement of multiple areas of the neuraxis, the eye and multiple intracranial sites can occur in the absence of obvious systemic lymphoma. The role of surgery in their treatment is uncertain. A combination of radiotherapy and chemotherapy can increase the length of survival. The prognosis, however, remains poor in comparison with nodal lymphomas, and particularly so in those with AIDS.

Primary cerebral lymphoma: report of 24 patients and review of the literature

A retrospective study of 24 patients with primary non-Hodgkin's cerebral lymphoma (non-immunocompromised) is presented. All patients were seen at the Royal Preston Hospital, Lancashire between 1976 and 1991. Fifteen patients were over the age of 50 years (range 27-84). The commonest clinical presentation, seen in 16 patients was of an expanding space-occupying lesion. The diagnosis was suspected from the radiological findings but confirmation in every case was by histological examination of biopsy or necropsy material. The tumours were treated either by surgical excision or by biopsy and radiotherapy. Chemotherapy was given in two patients. Despite these measures the mean survival time was 3.6 months. The clinical radiological and pathological features of these tumours are highlighted with particular emphasis on the use of stereotactic biopsy, immunohistochemistry and chemotherapy in diagnosis and treatment.

Primary central nervous system lymphomas--an update

Primary CNS lymphomas (PCNSL), until recently representing about 1% of all brain tumors, show dramatically increased incidence both in high-risk groups (immunocompromised, AIDS) and in the general population. They are extranodal diffuse non-Hodgkin's lymphomas, the morphology and classification of which are identical to those of systemic lymphomas, although PCNSL show different biological behavior and diagnosis according to the New Working Formulation and updated Kiel classification may be difficult. The majority are large B cell variants of high-grade malignancy; low-grade subtypes and T cell lymphomas are rare. Sixty per cent occur in the supratentorial space (hemispheres, periventricular) and 12% in the posterior fossa; 30% are multiple (50%-70% in AIDS). PCNSL show a male preponderance with a peak incidence in the 5th-7th decade (3rd-4th in AIDS). The duration of diffuse or focal clinical symptoms averages 1-2 months. Computed tomography and magnetic resonance imaging scans show single or multiple or diffuse, often typical lesions. Diagnosis is achieved by evaluation of stereotactic biopsy material or cerebrospinal fluid cytology using immunocytological markers. Current therapy in immunocompetent patients, radiation plus corticosteroids and pre- or postradiation polychemotherapy, shows response rates of 85% with a median survival of 17-44 months, a prognosis similar to that for glioblastoma. Meningeal PCNSL is treated with intrathecal methotrexate or cytosine arabinoside. Transliquoral seeding of PCNSL is frequent, distant metastases occurring in 6%-8%. Therapy of AIDS-related PCNSL makes use of radiation and corticosteroids, and rarely of chemotherapy. The pathogenesis of PCNSL is unknown, but Epstein-Barr virus may be a contributory factor.