title: A comparison of imaging, clinical, and pathologic aspects of space-occupying lesions within the brain in patients with acquired immune deficiency syndrome.
abstract: Patients with acquired immune deficiency syndrome (AIDS) often have central nervous system mass lesions. Since clinical signs, symptoms, and results of imaging techniques are generally nonspecific, brain biopsy has been considered to be the optimal method for establishing a definitive diagnosis. In an effort to define better the imaging characteristics of such lesions, we retrospectively analyzed 24 patients with AIDS who had intracerebral space-occupying lesions, with subsequent definitive histologic diagnosis and/or a diagnostic response to empiric therapy for toxoplasmosis. We employed computerized tomography (CT), double-dose-delay CT (DDD-CT), and nuclear magnetic resonance imaging (NMRI) of the brain. Sixteen patients had toxoplasmosis, seven had high-grade non-Hodgkins lymphoma, and one had progressive multifocal leukoencephalopathy that was due to herpes simplex virus II (HPML). Toxoplasmosis generally occurred as multiple, small (2 cm or smaller), hypodense or isodense lesions with variable enhancement. Malignant lymphomas appeared as single lesions, always larger than 3 cm, which were isodense or hyperdense, with internal enhancement. The combined radiologic criteria of size, multiplicity, and pre- and postcontrast appearance were useful in differentiating these two pathologic processes. The best single discriminant of toxoplasmosis versus lymphoma was the average lesion size of less than 3 cm. In our experience, diagnostic brain biopsy may be averted when lesions typical of toxoplasmosis are seen. DDD-CT and NMRI may be useful in identifying lesions that are not seen optimally on routine CT.
authors.affiliation: Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033.
authors.forename: P S
authors.initials: PS
authors.lastname: Gill
authors.forename: R A
authors.initials: RA
authors.lastname: Graham
authors.forename: W
authors.initials: W
authors.lastname: Boswell
authors.forename: P
authors.initials: P
authors.lastname: Meyer
authors.forename: M
authors.initials: M
authors.lastname: Krailo
authors.forename: A M
authors.initials: AM
authors.lastname: Levine
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006561:Herpes Simplex / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014123:Toxoplasmosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology