Cerebral toxoplasmosis in a diffuse large B cell lymphoma patient

Abstract

BackgroundToxoplasmosis is an opportunistic protozoal infection that has, until now, probably been an underestimated cause of encephalitis in patients with hematological malignancies, independent of stem cell or bone marrow transplant. T and B cell depleting regimens are probably an important risk factor for reactivation of a latent toxoplasma infection in these patients.Case reportWe describe a 62-year-old HIV-negative right-handed Caucasian female with systemic diffuse large B cell lymphoma who presented with sudden onset of high fever, headache, altered mental status, ataxia and findings of pancytopenia, a few days after receiving her final, 8th cycle of rituximab, cyclophosphamide, vincristine, doxorubicin, prednisolone (R-CHOP) chemotherapy regimen. A progression of lymphoma to the central nervous system was suspected. MRI of the head revealed multiple on T2 and fluid attenuated inversion recovery (FLAIR) hyperintense parenchymal lesions with mild surrounding edema, located in both cerebral and cerebellar hemispheres that demonstrated moderate gadolinium enhancement. The polymerase chain reaction on cerebrospinal fluid (CSF PCR) was positive for Toxoplasma gondii. The patient was diagnosed with toxoplasmic encephalitis and successfully treated with sulfadiazine, pyrimethamine and folic acid. Due to the need for maintenance therapy with rituximab for lymphoma remission, the patient now continues with secondary prophylaxis of toxoplasmosis.ConclusionsWith this case report, we wish to emphasize the need to consider cerebral toxoplasmosis in patients with hematological malignancies on immunosuppressive therapy when presenting with new neurologic deficits. In such patients, there are numerous differential diagnoses for cerebral toxoplasmosis, and the CNS lymphoma is the most difficult among all to distinguish it from. If left untreated, cerebral toxoplasmosis has a high mortality rate; therefore early recognition and treatment are of essential importance.

Neurotoxoplasmosis in a Patient with Chronic Lymphocytic Leukemia

“…Neurotoxoplasmosis remains a common cerebral opportunistic infection in patients with acquired immune deficiency syndrome. This case emphasizes the need to consider toxoplasmosis in immunocompromised patients with hematological malignancies, representing an emerging group at risk [2][3][4][5]. Early diagnosis is essential to ensure early treatment, but clinical presentation of cerebral toxoplasmosis is unspecific [4].…”

Cerebral toxoplasmosis after rituximab for pemphigus vulgaris

“…Only 4 cases of cerebral toxoplasmosis following rituximab therapy have previously been reported (Table I). 4, 5, 6, 7 Neither PML nor cerebral toxoplasmosis has been described in the context of rituximab treatment for dermatologic indications. In all cases of cerebral toxoplasmosis following rituximab therapy, patients were taking another immunosuppressant medication in addition to rituximab.…”

“…As an immunomodulator, rituximab carries a black box warning for potentially fatal infusion reactions, severe mucocutaneous reactions, hepatitis B virus reactivation, and progressive multifocal leukoencephalopathy (PML) 2 . Rarely, rituximab has been associated with cerebral toxoplasmosis infection 4, 5, 6, 7. Here we present a case of cerebral toxoplasmosis infection in a patient treated with rituximab for pemphigus vulgaris, along with a brief review of central nervous system (CNS) toxoplasmosis in the setting of rituximab therapy.…”

Cerebral Toxoplasmosis: A Case Report with Correlation of Radiographic Imaging, Surgical Pathology, and Autopsy Findings

“…Rituximab does have a good safety profile; however, concerns of increasing risk of infection are being raised. It does cause a rapid depletion of B-cells, but may also influence T-cell immunity and predispose patients to opportunistic infections (7). This exact mechanism of T-cell immunity impairment is not entirely understood at the present time.…”

“…An eccentric (asymmetric) target sign may be seen on contrast T1-weighted images, which exhibits a small enhancing nodule along the wall of the enhancing ring. This is highly specific for cerebral toxoplasmosis, but is seen in less than 30% of cases (6,7). Additionally, lesions in lymphoma tend to be more locally infiltrative and a butterfly-pattern of spread and enhancement is more suggestive of lym-phoma.…”