Primary central nervous system lymphoma in acquired immune deficiency syndrome. A clinical and pathologic study with results of treatment with radiation

A comparison of survival of patients treated for AIDS-related central nervous system lymphoma with and without tissue diagnosis

PURPOSE

This is a retrospective review of the treatment outcome of radiation therapy (RT) in acquired immune-deficiency syndrome (AIDS) patients with presumed primary central nervous system (CNS) non-Hodgkin's lymphoma (NHL), with and without tissue verification.

METHODS AND MATERIALS

Twenty-seven patients with AIDS-related CNS NHL were treated between 1986 and 1992. They were divided into two groups. Group 1 consisted of nine patients with a positive histology for NHL. They were treated with dexamethasone (DXM) and whole brain RT. Group 2 consisted of 18 patients who, because of unique circumstances, were treated without histologic confirmation of NHL. Rapid clinical and/or radiologic response to DXM and whole-brain RT was interpreted as NHL.

RESULTS

For group 1, the response rate was 87.5%, mean survival 6.1 months, and median survival 4.5 months. For group 2, the response rate was 72.2%, mean survival 5.2 months, and median survival 4.5 months. The overall response rate was 76.9%, mean survival 5.8 months, and median survival 4.5 months.

CONCLUSIONS

In instances where a tissue diagnosis cannot be established, a positive response to an empiric trial of DXM and RT to 20 Gy may constitute presumptive evidence of NHL.

Malignant lymphomas in patients with HIV infection

During the last two decades, the occurrence of non-Hodgkin's lymphoma (NHLs) has been increasing both in the general population, in which their incidence doubled, and in people with human immunodeficiency virus (HIV) infection, in whom a 100-fold increase has been observed since the onset of the AIDS epidemic. HIV infected patients are living longer owing to advances in antiretroviral therapy and treatment of prophylaxis against opportunistic infections but because of their immunodeficiency they are at high risk of cancers, especially NHL. The natural history of cancers in patients with HIV infection differs from that of the general population. Unusual aspects of tumor localization, growth behaviour and therapeutical response, distinguish tumors in patients with from those without HIV infection. The pathologic and virological aspects of HIV-related tumors are peculiar and a pathological classification of HIV associated systemic lymphomas based on the morphological features of the two main types, i.e. blastic and anaplastic cell lymphomas has been formulated. The treatment of HIV-related neoplasms is controversial as it is not clear whether conventional therapy and in particular chemotherapy is able to modify the natural history of these malignancies in HIV setting. Moreover the treatment of HIV-related tumors presents several problems, due to the aggressive behaviours of tumors and because of immunosuppressive chemotherapy employed in patients with immunodeficiency.

Non-Hodgkin's lymphomas (NHL)

This synthesis of the literature on radiotherapy for non-Hodgkin's lymphomas is based on 158 scientific articles, including 16 randomized studies, 18 prospective studies, and 90 retrospective studies. These studies involve 14,137 patients. Non-Hodgkin's lymphomas are highly radiosensitive, and local recurrence following radiotherapy is unusual. Radiotherapy probably cures approximately 50% of both low-grade and high-grade malignant NHL at stage I. Involved field is apparently sufficient, however, higher doses are required for high-grade malignant lymphomas. Chemotherapy is recommended for stage II. Consolidation radiotherapy after chemotherapy may increase the number of complete remissions. The value of adjuvant radiotherapy has not been confirmed. Radiotherapy plays a limited role at stages III and IV. Radiotherapy is clearly indicated for extranodal localized disease in the skin and in the orbit of the eye. It is important to identify groups and subgroups in whom radiotherapy alone is sufficient, ie, the risk for distant recurrence is small. MALT lymphoma belongs to this group. Radiotherapy is often valuable in palliative situations.

Pathogenesis and classification of primary central nervous system lymphoma: an update

Primary central nervous system lymphoma has undergone a remarkable increase in incidence over the last decade, both in immunosuppressed and immunocompetent individuals. Its clinicopathologic evaluation requires knowledge of current hematopathologic systems for lymphoma classification, as well as specific understanding of unique central nervous system determinants. In immunocompromised individuals, the tumor has a constant association with Epstein-Barr virus. The form of Epstein-Barr virus in these tumors appears to be predominantly latent, however, the precise mechanism relating virus to tumor pathogenesis is still unclear. In immunocompetent patients, risk factors and oncogenic associations are completely unknown. Critical to the formation of these tumors is the trafficking of B-cells, whether pre- or post-transformation, across the blood-brain barrier. These B-cell migrations may require perturbations to the barrier that originate in or around neural parenchyma, such as localized injury or infection.

Additional experience with empiric radiotherapy for presumed human immunodeficiency virus-associated primary central nervous system lymphoma

BACKGROUND

In light of the steadily improving capability to treat opportunistic infections, the authors reviewed their recent experience with short course empiric radiotherapy for the treatment of human immunodeficiency virus (HIV)-associated presumed central nervous system (CNS) lymphoma.

METHODS

Medical records were reviewed of 32 previously unreported HIV-infected patients who had computed tomography and/or magnetic resonance imaging findings consistent with lymphoma, whose lesions had failed to respond to antitoxoplasmosis therapy and therefore subsequently treated with empiric radiotherapy to the cranium and meninges, nearly always 3000 cGy in 10 fractions.

RESULTS

The majority of patients were in poor general condition (median Karnofsky score = 50) when radiotherapy was initiated. Fifty percent improved during or after radiation. Median survival was 2.1 months.

CONCLUSIONS

Despite progress made in the past several years in the treatment of opportunistic infections and brief clinical response to radiotherapy, patients with acquired immunodeficiency syndrome who have a presumed diagnosis of CNS lymphoma continue to have extremely poor survival. Early biopsy in patients with lesions that fail to respond to empiric antitoxoplasmosis treatment or with lesions radiographically most consistent with lymphoma may improve outcome.

Multifocal inflammatory leukoencephalopathy associated with levamisole and 5-fluorouracil: case report

Levamisole and 5-fluorouracil have now become the standard chemotherapeutic regimen for patients with Stage III colon carcinoma. A case of multifocal inflammatory leukoencephalopathy secondary to levamisole alone or combination of levamisole and 5-fluorouracil is reported. Magnetic resonance imaging with gadolinium demonstrated multifocal contrast-enhancing frontal, parietal, occipital, and periventricular white matter lesions. A stereotactic biopsy revealed reactive gliosis and macrophage infiltration, without evidence of metastatic tumor. Despite continuation of 5-fluorouracil, resolution of contrast-enhancing lesions on magnetic resonance imaging without further neurological sequelae occurred when levamisole was stopped. The patient died with evidence of systemic metastasis 6 months later. Autopsy examination of the brain revealed multifocal demyelinating lesions, with no evidence of metastatic tumor. Immunoperoxidase studies of demyelinated lesions demonstrated infiltrating macrophages strongly positive for Class II antigens, interleukin-6, and interleukin-1 alpha. Surrounding astrocytes were positive for granulocyte macrophage colony-stimulating factor. Small numbers of perivascular T cells were present. This patient represents the first autopsy documented case of levamisole associated multifocal inflammatory leukoencephalopathy.

Long survival in patients with acquired immune deficiency syndrome-related primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is the most common brain tumor occurring in patients with acquired immune deficiency syndrome (AIDS). After diagnosis of PCNSL, the median survival time is 2-5 months with treatment with whole brain irradiation (WBI).

METHODS

Four (of approximately 40) patients with AIDS and PCNSL seen by the University of California, San Diego (UCSD) Neuro-Oncology service were treated with multimodal therapy, including WBI with hydroxyurea, followed by 3 cycles of procarbazine/lomustine/vincristine (PCV) chemotherapy.

RESULTS

Survival after tumor diagnosis ranged from 11 to 16 months, with a median of 13.5 months.

CONCLUSION

Selected patients with AIDS and PCNSL may have long survival when treated with multimodal therapy.

Stereotactic biopsy in cerebral lesions of AIDS

The experiences with stereotactic biopsies in 121 patients with AIDS compared to 142 non-AIDS patients are presented. In the AIDS group most of the tumors (38) were lymphomas (34). Other frequent diagnoses have been progressive multifocal leukoencephalopathy (20) and toxoplasmosis (16)--although most AIDS patients already had been treated for toxoplasmosis, and those who responded to it did not undergo biopsy. Initially among the AIDS patients there was a tendency of delayed intracranial bleeding (4 cases, 3 of them fatal). After initiation of a prophylactic coagulopathy protocol no other such complications have occurred in the following 70 biopsies.

The neurologic complications of human immunodeficiency virus infection

The physician caring for HIV-1-infected patients must have a good working knowledge of the broad spectrum of neurologic diseases that occur in association with this infection. As with any other neurologic disorder, the site of the neuraxis that is affected must be properly identified. In HIV-1-infected persons, more than one site may be involved simultaneously, such as the coexistence of myelopathy and peripheral neuropathy, often resulting in a confusing array of neurologic signs and symptoms. The frequent occurrence of two or more diseases affecting the neuraxis, such as progressive multifocal leukoencephalopathy and toxoplasmosis, further complicates the picture. With the AIDS patient, the physician cannot rely on the clinical adage that all attempts should be made to ascribe the patient's problems to one disease. Often, it is not the case. As with other illnesses, the approach to the HIV-1-infected person with neurologic disease needs to be thorough and fluid. After rendering a diagnosis and embarking on therapy, the physician needs to be open minded about the possibility of an incorrect or additional diagnosis not previously considered. Lastly, despite all the knowledge that has been accumulated in the first decade of the AIDS epidemic, new illnesses occurring with HIV-1 infection are recognized with regularity. The physician must always bear in mind that the illness with which he or she is confronted may be one that has not been previously described.

Neuropathology of Immunosuppression

Traditionally, the brain has been considered an "immunologically privileged" organ. Under normal conditions, the blood-brain barrier (BBB) is highly effective in preventing both cellular and humoral constituents of the blood from entering the brain parenchyma. In certain pathological conditions, such as viral infections and demyelinating disorders, the BBB may become altered, activated T cells and monocytes may gain access to the brain parenchyma, and microglia may assume the functions of antigen-presenting cells and macrophages. Naturally-occurring or clinically-induced immunosuppression may dramatically alter various cellular and/or humoral aspects of the immune system. Consequently, the brain may become susceptible to disorders that would otherwise be excluded or may develop more severe manifestations of diseases, such as certain infections. This review considers the neuropathologic aspects of various conditions that may be encountered in the setting of both acquired and inherited immunosuppression. The major categories include infectious, neoplastic, vascular, and metabolic disorders. The review also briefly addresses the neuropathology of complications of chemotherapeutic agents, radiotherapy, and organ transplantation inasmuch as they often occur in the clinical setting of acquired immunosuppression.

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 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.