PMC10070335_01
Pre- (a) and postcontrast (b) computed tomography scan of the brain revealed a 2 cm diameter hypodense nodular lesion in the right thalamus with perilesional edema causing moderate mass effect, with colliquative features inside.
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F1
Pre- and postcontrast computed tomography (CT) scans of the brain [Figure 1] revealed a 2 cm diameter hypodense nodular lesion in the right thalamus with perilesional edema causing moderate mass effect, with colliquative features inside.
Brain magnetic resonance imaging without contrast showing a right thalamic nodular lesion measuring 25 x 22 mm, with perilesional edema. The nodule appeared hypointense in fluid-attenuated inversion recovery sequences (a), isointense on T1-weighted (b) and reg-diffusion-weighted imaging sequences (c), and hypointense on T2-weighted images (d-f). The nodule and associated edema resulted in slight compression of the ipsilateral ventricle.
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F2
Brain magnetic resonance imaging (MRI) pre and post contrast [Figure 2] confirmed a right thalamic nodular lesion measuring 25 x 22 mm, with perilesional edema.
Brain MRI, post-contrast T1 weighted sequences showing irregular post-contrast enhancement particularly along the nodule walls (ring enhancement); white arrows (panel C) indicate an intranodular enhancing component (similar to "eccentric target sign").
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F3
In the coronal sections [Figure 3], there was an irregular postcontrast enhancement, especially along the nodule walls. Was also visible an inner enhancing nodule, which should have raised the suspicion of parasitic infection [Figure 3, Panel C].
Preoperative planning with 3D reconstruction to simulate the surgical trajectory avoiding functional areas and tracts (Medtronic Stealth S8, Minneapolis). A coronal trajectory was used passing lateral to the lateral ventricle wall.
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Considering the deep location in an eloquent area, it was decided to perform a neuronavigated stereotaxic biopsy [Figure 4]. Preoperative planning was conducted using three-dimensional reconstruction to simulate the surgical trajectory and avoid functional areas and tracts (StealthStation S8; Medtronic, Minneapolis, Minnesota, USA) [Figure 4].
Staining with PAS. x40. Image of brain tissue with tachyzoites in a Toxoplasma infection (a). Immunohistochemical staining showing cytomegalovirus superinfection in a patient with cerebral toxoplasmosis. Image at x40 (b).
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Rounded structures containing eosinophilic corpuscles inside the infiltrate were found, suggesting a protozoal infection, and allowing the diagnosis of cerebral toxoplasmosis [Figure 5].
Total-body computed tomography scan showing multiple small abscesses in liver, kidney and thyroid gland (red arrows), intestinal walls thickening (yellow arrow), and pleural effusion (blue arrows).
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A total-body CT scan revealed multiple abscesses (liver, kidney, and thyroid gland), intestinal walls thickening, and pleural effusion [Figure 6].