[Acquired cerebral toxoplasmosis in adults. Clinical and neuropathologic study]

Two cases of acquired cerebral toxoplasmosis in adults are reported. In the first case no subjacent disease was found, and the neurological signs were of a meningo-encephalitic type with disorders of consciousness and a C.S.F. cellular reaction. A second case was observed in the course of the treatment of Waldenström disease by chloraminophene. The neurological signs were bifocal, and the C.S.F. showed a moderate increase of protein. In both cases C.T. scan showed contrast enhanced and hypodense areas. In the first case the enhancement was heterogenous and the hypodense area occupied the whole right hemisphere. The second case showed two ring enhancements in the left frontal and the right occipital regions. A cerebral biopsy was performed in both cases but no parasite was found. The diagnosis was presumed to be malignant lymphoma or encephalitis in the first case, glioblastoma in the second. No specific treatment was administered and the patients died within a few weeks. The complete pathological study by light and electron microscopy showed free and cystic forms of Toxoplasma Gondii. The results of the neuropathological examination and the thorough study of the biopsy specimens were compared to the pathological findings in the literature. The particular character of the necrosis and the inflammatory encephalitic reaction in the absence of the parasite may suggest the diagnosis when the clinical, biological and radiological data are compared.