Figure 1. A) Magnetic resonance imaging (MRI) of the patient's brain showing a large lesion in the left cerebellar hemisphere. B) MRI in a different plane taken at the same time. Lesions are evident in the right thalamus and the right half of the pons. C) Blood vessel in brain parenchyma with large numbers of Acanthamoeba in the perivascular space (hematoxylin and eosin stained, magnification ×100). Inset, higher magnification (×1,000) showing nuclear morphology of the ameba. The dark-stained ameba nucleus with a central nucleolus is distinctive. D) Immunofluorescent staining of perivascular brain tissue showing many amebae (magnification ×100).