Final Diagnosis -- Cerebral Toxoplasmosis



In light of the parasitic nature of the lesion, HIV serology was initiated. Two independent sera were positive for anti-HIV-antibodies, and Western blot analysis confirmed the presence of specific bands. Further blood tests showed a low CD4+/CD8+ ratio, and quantitative PCR from the blood revealed a high virus load. Taken together, these findings not only established advanced HIV infection, but also founded the diagnosis of AIDS, with the cerebral lesion constituting the AIDS-defining disease (1). Only after being confronted with these results, the patient gave notice of being homosexual.

Following diagnosis, the patient was treated with pyrimethamine, sulfalene, and folate. During the entire postoperative course, there were no signs of aphasia present. A control CT scan seven weeks after surgery and five weeks following the initiation of the antiparasitic drug regimen showed an almost complete remission of the temporal lesion (Fig. 1c). At this time, antiretroviral triple therapy was started. Six months after the initial admission, the patient was free of symptoms, and the EEG focus was no more detectable. He intended to go back to work.

Toxoplasmic encephalitis is the most frequent cause of acute neurological deterioration in AIDS patients. It occurs due to reactivation following a previous inapparent infection in immune-compromised individuals (8). Although toxoplasma lesions can present as ring enhancing lesions in CT and MRI, singular manifestations are less common (3,8), especially in severely immunosuppressed patients who often present with encephalitic symptoms (8,9). In patients with an established diagnosis of AIDS, CNS symptoms, and brain masses, toxoplasmosis and primary CNS lymphoma are the most likely causes (3). It is now established that in this constellation, anti-Toxoplasma drug therapy is started, and biopsy only carried out if the patient deteriorates (7). However, gliomas have also been reported in AIDS patients (2), and in our patient, imaging was suggestive of glioma, while there was no evidence for HIV infection at the time of admission.

Our report stresses the importance of considering undiagnosed HIV infection in patients of risk groups presenting with a cerebral mass lesion. Moreover, this case underlines the value of molecular pathological tools as a supplement to conventional histological and immuno-cytochemical examinations on biopsy specimens (4,5,6). Using modern triple antiretroviral regimens, the prognosis of this condition has improved considerably over the past years.


  1. Centers for Disease Control and Prevention (1993) Revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults. Morbidity and Mortality weekly Report 41. (
  2. Chamberlain MC (1994) Gliomas in patients with aquired immune deficiency syndrome. Cancer 74: 1912-1914
  3. Dina TS (1991) Primary central nervous system lymphoma versus toxoplasmosis in AIDS. Radiology 179: 823-828
  4. Dupon M, Cazenave J, Pellegrin JL, Ragnaud JM, Cheyrou A, Fischer I, Leng B, Lacut JY (1995) Detection of toxoplasma gondii by PCR and tissue culture in cerebrospinal fluid and blood of human immunodeficiency virus-seropositive patients. J Clin Microbiol 33: 2421-2426
  5. Isenmann S, Zimmermann, DR, Wichmann W, Moll C. (1996). Tuberculoma mimicking meningioma of the falx cerebri. PCR diagnosis from mycobacterial DNA from formalin-fixed tissue. Clin Neuropathol 15: 155-158
  6. Khalifa K el-S, Roth A, Roth B, Arasteh KN, Janitschke K (1994) Value of PCR for evaluating occurrence of parasitemia in immunocompromised patients with cerebral and extracerebral toxoplasmosis. J Clin Microbiol 32: 2813-2819
  7. Luft BJ, Hafner R, Korzun AH, Leport C, Antoniskis D, Bosler EM, Bourland DD, Uttamachandani R, Fuhrer J, Jacobson J, Morlat P, Vilde JL, Remington JS (1993) Toxoplasmic encephalitis in patients with the aquired immunodeficiency syndrome. N Engl J Med 329: 995-1000
  8. Navia BA, Petito CK, Gold JWM, Cho ES, Jordan BD, Price RW (1986) Cerebral toxoplasmosis complicating the aquired immunodeficiency syndrome: clinical and neuropathological findings in 27 patients. Ann Neurol 19: 224-238
  9. Price RW (1996) Neurological complications of HIV infection. Lancet 348: 445-452

Contributed by Stefan Isenmann, MD, Christian Aepinus, MD, Martin Skalej, MD, Antje Bornemann, MD, Ernst H. Grote, MD


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