Primary intracranial neoplasms in patients with HIV

[Epstein-Barr virus associated central nervous system leiomyosarcoma occurring after renal transplantation: case report and review of the literature]

Central nervous system leiomyosarcomas are extremely rare, however, they became more frequent among immunodeficient patients, either in a patients infected with human immunodeficiency virus (HIV), or after organ transplantation. The data of the literature indicate that the infection by Epstein-Barr virus (EBV) plays a causal role in the development of these tumours but its precise role in the oncogenesis remains unresolved. We report a new case of EBV associated leiomyosarcoma of the left cavernous sinus occurring after renal transplantation. The epidemiological, clinical, pathological and therapeutic characteristics of these tumours are discussed.

Glioblastoma in kidney transplant recipients. Report of five cases

Five patients who developed an intracranial glioblastoma after a kidney transplant are described. All patients underwent surgical removal of the lesion and eventually radiation therapy, but none of them is still alive at follow-up. The possibility of tumours occurring in transplant recipients is a recognised entity and several series have been reported. Nevertheless, little consideration has been paid to post-transplant gliomas and a precise evaluation of this risk is still lacking. Several hypotheses have been proposed to explain a possible link. One possible factor may be the immunosuppressive state of recipients as a result of post-transplant administration of immunosuppressive drugs, as it is known that gliomas have an higher incidence in HIV-infected patients. However, it is not yet clear whether immunosuppressive drugs function as a direct transforming factor.

Human immunodeficiency virus type-1 Tat/co-activator acetyltransferase interactions inhibit p53Lys-320 acetylation and p53-responsive transcription

Patients with AIDS are at increased risk for developing various neoplasms, including Hodgkin's and non-Hodgkin's lymphomas, Kaposi's sarcomas, and anal-rectal carcinomas, suggestive that human immunodeficiency virus type-1 infection might promote establishment of AIDS-related cancers. Tat, the viral trans-activator, can be endocytosed by uninfected cells and has been shown to inhibit p53 functions, providing a candidate mechanism through which the human immunodeficiency virus type-1 might contribute to malignant transformation. Because Tat has been shown to interact with histone acetyltransferase domains of p300/cAMP-responsive element-binding protein (CREB)-binding protein and p300/CREB-binding protein-associated factor, we have investigated whether Tat might alter p53 acetylation and tumor suppressor-responsive transcription. Here, we demonstrate that both Tat and p53 co-localize with p300/CREB-binding protein-associated factor and p300 in nuclei of IMR-32 human neuroblastoma cells and in PC-12 pheochromocytoma cells. Further, p53 trans-activation of the 14-3-3varsigma promoter was markedly repressed by Tat-histone acetyltransferase interactions, and p53 acetylation by p300/CREB-binding protein-associated factor on residue Lys(320) was diminished as a result of Tat-histone acetyltransferase binding in vivo and in vitro. Tat also inhibited p53 acetylation by p300 in a dosage-dependent manner in vitro. Finally, HIV-1-infected Molt-4 cells displayed reduced p53 acetylation on lysines 320 and 373 in response to UV irradiation. Our results allude to a mechanism whereby the human immunodeficiency virus type-1 trans-activator might impair tumor suppressor functions in immune/neuronal-derived cells, thus favoring the establishment of neoplasia during AIDS.

Primary central nervous system lymphoma involving the optic chiasm in AIDS

OBJECTIVE

To report visual loss resulting from chiasmal involvement by primary central nervous system lymphoma (PCNSL).

MATERIALS AND METHODS

Case report.

RESULTS

A patient with the acquired immune deficiency syndrome (AIDS) presented with visual loss resulting from PCNSL involving the optic chiasm. The clinical findings, neuroimaging, pathology, and treatment of this patient are described.

CONCLUSIONS

Although rare, clinicians should consider PCNSL in the differential of a hypothalamic/chiasmal mass, especially in a patient with AIDS.

Central nervous system leiomyosarcoma in patients with acquired immunodeficiency syndrome. Report of two cases

Leiomyosarcomas (LMSs) of the central nervous system are extremely rare; however, they are becoming more prevalent in immunocompromised patients. The authors present the cases of two patients with acquired immunodeficiency syndrome: one with LMS of the thoracic vertebral body and the other with LMS originating from the region of the cavernous sinus. The epidemiological and histological characteristics of LMS and its association with latent Epstein-Barr virus are discussed, as well as the treatments for this neoplasm.