PMC8247755_01
(a) Axial plane contrast-enhanced MRI demonstrating lesion at time of initial presentation. (b) Coronal plane contrast-enhanced MRI demonstrating lesion at time of initial presentation. (c) Axial plane contrast-enhanced MRI demonstrating interval growth 1 month after initial presentation. (d) Coronal plane contrast-enhanced MRI demonstrating interval growth 1 month after initial presentation.
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F1
MRI brain demonstrated a contrast-enhancing lesion centered at the left choroidal fissure between the amygdala and cerebral peduncle [Figure 1a and b]. Repeat MRI brain demonstrated that the lesion had nearly doubled in size [Figure 1c and d].
Three-dimensional reconstruction of CT angiography. Lateral projection demonstrates contrast uptake of hypervascular lesion with no discrete arterial connection. The anterior choroidal artery is not visualized.
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F2
CTA did not demonstrate any arterial filling of the lesion [Figure 2]; although the anterior choroidal artery was not seen on that study.
PMC8247755_02
Inflammatory myofibroblastic tumor. Examination of the tumor on low magnification revealed a fairly well-demarcated cellular proliferation, demonstrating an incomplete fibrous pseudocapsule on the periphery (a, asterisk, x5). The tumor was composed of spindled cells arranged in short fascicles with a background of prominent, multifocal acute and chronic inflammation, as well as frequent blood vessels (b, x20). Tumor cells showed elongated, monotonous nuclei with small nucleoli (c, x40) and were diffusely and strongly reactive for smooth muscle actin immunohistochemistry (d, x40). (a-c) Hematoxylin and eosin. (d) Smooth muscle actin immunohistochemistry.
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F3
Microscopic examination of the tumor with hematoxylin and eosin stained sections demonstrated a proliferation of spindle cells arranged in short fascicles, with a prominent background of acute and chronic inflammation [Figure 3].
Postoperative MRI brain. (a) Diffusion-weighted imaging demonstrates a small area of restricted diffusion in the left internal capsule. (b) Fluid-attenuated inversion recovery sequence demonstrates postoperative changes of the transgyral approach to the tumor.
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F4
MRI demonstrated a small infarct of the left posterior limb of the internal capsule consistent with an anterior choroidal artery infarct [Figure 4].