case_images: PMC11813643_01
case_images: Non-contrast cranial computed tomography (CT). CT scan with sagittal (A), axial (B), coronal (C) views reveals ovoid lesions in the frontotemporal region (arachnoid cysts). No abnormalities are observed in the brainstem or cerebellum, and normal differentiation between gray and white matter is maintained.
case_images: cureus-0017-00000077343-i01.jpg
case_images: PMC11813643_01_cureus-0017-00000077343-i01.jpg
case_images: FIG1
case_images: CT findings revealed the presence of probable septated AC with possible left temporal lobe and frontal lobe displacement (Figure 1).
case_images: Brain Magnetic Resonance Imaging (MRI). Simple cranial MRI, T2-weighted coronal slices (A-C), T2-weighted axial slices (D-F). Contrast MRI axial slices in T1 weighting (G-I). The presence of arachnoid cysts occupying the region of the frontal lobes, hyperintense in T2, hypointense in T1, and without enhancement following contrast administration. The remaining cerebral hemispheres showed no evidence of space-occupying lesions, with normal convolution depth and well-differentiated sulci and fissures. Additionally, the cerebellum, cerebellar base, pons, and medulla were unremarkable with no abnormalities observed.
case_images: cureus-0017-00000077343-i02.jpg
case_images: PMC11813643_01_cureus-0017-00000077343-i02.jpg
case_images: FIG2
case_images: On the left side, the cyst measured 14.35 cm x 5.61 cm x 5.92 cm along the longitudinal, anteroposterior, and transverse axes, while on the right side it measured 11.33 cm x 5.11 cm x 4.78 cm (Figure 2).
case_images: Non-contrast cranial computed tomography (CT). CT scans with sagittal (A), axial (B), and coronal (C) views. Revealed heterogeneous lesions in the frontal region. These findings were suggestive of chronic membranes with evidence of rebleeding and a mass effect.
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case_images: PMC11813643_01_cureus-0017-00000077343-i03.jpg
case_images: FIG3
case_images: Subsequently, a follow-up CT was performed, revealing heterogeneous lesions consistent with rebleeding and a mass effect (Figure 3).
case_images: Surgical findings. The surgical image demonstrates the opening of the dura mater, revealing thick vascular membranes and a consolidated hematoma with a liquid component resembling "burnt motor oil" within the subdural space (A). Aspiration, hemostasis, and removal of a dense, fibrous vascular membrane adherent to the brain parenchyma, consistent with a hemorrhagic arachnoid cyst, were successfully performed (B). There was an absence of brain parenchyma corresponding to the frontal lobes (C).
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case_images: PMC11813643_01_cureus-0017-00000077343-i04.jpg
case_images: FIG4
case_images: Additionally, there was a loss of brain volume in the region corresponding to the frontal lobes (Figure 4).
case_images: Postoperative Non-contrast Cranial Computed Tomography (CT). CT scans with sagittal (A), axial (B), and coronal (C) views. The images revealed the presence of arachnoid cysts occupying the frontal region, without evidence of rebleeding.
case_images: cureus-0017-00000077343-i05.jpg
case_images: PMC11813643_01_cureus-0017-00000077343-i05.jpg
case_images: FIG5
case_images: It was later decided to discharge the patient in the late postoperative period, as neurological progress was satisfactory and a follow-up CT showed no evidence of rebleeding (Figure 5).