Use of CT and MR imaging to distinguish intracranial lesions and to define the need for biopsy in AIDS patients

Abstract

To explore the potential usefulness of imaging studies in the diagnosis of focal central nervous system (CNS) lesions associated with acquired immunodeficiency syndrome (AIDS), the authors retrospectively examined the radiographic studies of 149 AIDS patients who presented with signs and symptoms of the three most common focal CNS lesions. Of these patients, 74 (50%) had Toxoplasma abscesses, 45 (30%) had primary CNS lymphoma, and 30 patients (20%) had progressive multifocal leukoencephalopathy (PML). Magnetic resonance (MR) imaging was more sensitive than computerized tomography (CT) in detecting lesions, especially in cases of PML. Whereas CT was unable to distinguish mass lesions caused by toxoplasmosis from those caused by lymphoma, 71% of the solitary lesions seen on MR images were lymphomas. These results indicate that empirical treatment for toxoplasmosis, the most common initial treatment for AIDS patients with neurological symptoms stemming from mass lesions, is not likely to be successful for patients with solitary lesions on MR images. Rather, early biopsy is advisable. If the presence of lymphoma is confirmed, the rapid initiation of treatment can allow prolonged high-quality survival.

Stereotactic biopsy for intracranial lesions: clinical-pathological compatibility in 60 patients

“…Regarding neoplasic lesions, the rate was 83%, while 83% were obtained considering all tissue samples. Our results are in accordance to those verified in literature, with positivity rates varying from 64 to 95%, with lower rates for inflammatory lesions or low malignancy grade lesions 5,[23][24][25][26] .…”

“…Inexperience of surgical staff can lead to bad positioning of stereotactic frame, technical difficulty to obtain tissue samples or incorrect transportation. The use of smear techniques or other pathological analysis strategies during surgical procedure increase the success rate, reducing the rate of non-relevant samples for diagnosis 25,26 .…”

Abordagem estereotáxica guiada por imagem de lesões do sistema nervoso central: precisão diagnóstica, morbidade, mortalidade

“…Considerando o diagnóstico etiológico, nossa acurácia encontra-se em 82,66%: gliose (1 caso), processo inflamatório (5 casos), tecido normal (2 casos) e alteração tecidual inconclusiva (5 casos). Analisando nossas falhas diagnósticas encontramos alguns fatores de erro: escolha do alvo a ser biopsiado, impossibilidade de confirmação por congelação no intra-operatório, e lesões em pacientes com AIDS que não se realçavam ao contraste 17,19,22,23 . Em relação a este último fator Chappell e col. em 1992 estudando 25 pacientes com AIDS submetidos a biópsia estereotáxica guiada por TC observaram que nas lesões que não realçavam após contraste venoso o índice diagnóstico foi de apenas 67% e o resultado da biópsia não influenciou o tratamento.…”

“…Os pacientes com AIDS apresentam características específicas, pois o diagnóstico radiológico apresenta erro de 20-25% 23 . Em até 50% das lesões intracranianas dos pacientes com AIDS há tratamento específico.…”

Intracranial vascular complications in AIDS

“…Чаще всего на фоне резкого понижения иммунокомпетентности (количество клеток с CD4-рецепторами менее 200/ мкл) наблюдаются оппортунистические инфекции ЦНС: токсоплазмоз, криптококковый менингит или абсцесс, цитомегаловирус (ЦМВ) и прогессирующая мультифокальная лейкоэнцефалопатия [19][20][21].…”