Presentation
Known case of HIV/AIDS presented with headache and neurological deficit of progressive nature.
Patient Data
An ill-defined irregular strongly enhancing altered signal intensity lesion with central few non-enhancing necrotic areas; is noted involving the corpus callosum extending into subependymal periventricular region of bilateral lateral ventricles and adjacent white matter of frontal and parietal lobes. The lesion is hypointense on T1 (not available), isointense on T2/FLAIR and showed restricted diffusion on DWI (not available). There is significant perilesional edema noted resulting in effacement of underlying cortical sulci.
MR spectroscopy reveals significant elevation of choline and reduction of NAA and creatine levels in the areas of enhancement. In addition there is significantly raised choline/creatine ratio of 2.9 with elevated lipid/lactate at 1.3 ppm which showed inversion on TE 135 consistant with areas of necrosis.
Imaging findings, enhancement pattern and spectroscopic findings in a known case of HIV/AIDS are suggestive of primary CNS lymphoma (PCNSL).
Case Discussion
The other differentials for this particular appearance in an immunocompromised individual may include:
-
toxoplasmosis:
- presence of subependymal spread suggests PCNSL
- significant choline peak elevation not generally observed in toxoplasmosis
- markedly elevated lipid/lactate peak seen in toxoplasmosis
- on perfusion weighted imaging (PWI) there is markedly increased rCBV seen in PCNSL which is relatively diminished in toxoplasmosis
- hemorrhage can be seen in toxoplasmosis but rarely in PCNSL
- glioblastoma multiforme:
- parenchymal and extra-axial sarcoidosis
- metastasis