PMC8769458_01
MRI findings at the time of admission. T1-weighted sequence with gadolinium enhancement reveals a cystic mass in the right cavernous sinus (A). Fluid-attenuated inversion recovery (B), T2-weighted image (C), and T1-weighted image (D). T2-weighted image (C) shows the fluid-fluid level (arrow), and T2-weighted image (E) sequence reveals a lesion with a high-signal intensity in the left cavernous sinus. The prolactinoma is adjacent to the right cavernous sinus portion of the ICA on the T1-weighted sequence with gadolinium enhancement (F). The pituitary stalk is displaced by the compression of tumor (arrowhead). MRI: magnetic resonance imaging, ICA: internal carotid artery.
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F1
Gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) on admission revealed an abnormal right cavernous sinus, with an approximately 17 mm mass extending into the right cavernous portion of the internal carotid artery (ICA) and extending below the intracavernous ICA into the inferior cavernous sinus compartment (Knosp-Steiner classification grade 3B) (Fig. 1A-1D). A high-intensity lesion on the left side of the mass, which seemed to be a hemorrhage, was detected with T2-weighted imaging (Fig. 1E), and the hemorrhage also led to the formation of a fluid-fluid level (Fig. 1C). The tumor also decreased in size from 18.7 mm x 15.1 mm x 17.4 mm on admission (Fig. 1A and 1F) to 9.2 mm x 8.1 mm x 6.1 mm at 81 months after the commencement of medical therapy (Fig. 3G and 3H).
Angiography findings at the time of admission. Anterior-posterior (A) and lateral (B) views of right common carotid artery (ICA) angiography at the time of admission reveals no aneurysm in the cavernous portion of the ICA. ICA: internal carotid artery.
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Since a confirmed diagnosis of an aneurysm could not be made based on these findings, an angiography was performed; however, it failed to identify any specific abnormalities around the ICA (Fig. 2A and 2B).
Coronal MRI and MRA findings. Coronal T1-weighted sequence with GE images (A and B) and MRA (C) 30 months after cabergoline treatment of the prolactinoma. T1-weighted sequence with GE (A) reveals that the prolactinoma (arrowhead) extended to the lateral side of the ICA and is contiguous with the aneurysm (arrow). The coronal T1-weighted magnetic resonance images (D and E) and MRA images (F) 56 months after the initial treatment. Coronal fat suppression T1-weighted magnetic resonance images (G and H) and MRA images (I) 81 months after the initial treatment. A new aneurysm emerged in the cavernous portion of the right ICA (arrow) and has grown larger during the treatment of the prolactinoma (C, F, and I). MRI: magnetic resonance imaging, MRA: magnetic resonance angiography, GE: gadolinium enhancement, ICA: internal carotid artery, BA: basilar artery.
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Afterward, the patient's prolactin concentration progressively decreased, and the prolactin concentration was 3.2 ng/mL at 30 months (Fig. 3A and 3B), 2.6 ng/mL at 56 months (Fig. 3D and 3E), and 34.5 ng/mL at 81 months (Fig. 3G and 3H) after the commencement of cabergoline treatment. The tumor also decreased in size from 18.7 mm x 15.1 mm x 17.4 mm on admission (Fig. 1A and 1F) to 9.2 mm x 8.1 mm x 6.1 mm at 81 months after the commencement of medical therapy (Fig. 3G and 3H). However, approximately 30 months after the initiation of treatment, a brain MRI revealed a newly formed aneurysm in the cavernous segment of the right ICA (aneurysm maximum diameter: 1.8 mm) (Fig. 3C). The aneurysm continued to grow and reached a maximum diameter of 3.0 mm at 56 months and 10.4 mm at 81 months after the commencement of treatment (Fig. 3F and 3I).
Angiography findings before and after embolization of the right ICA. The aneurysm's diameter was 10.4 mm before embolization (A); after coil embolization, blood flow through the aneurysm was almost completely eliminated (B). ICA: internal carotid artery.
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The patient then underwent endovascular coil embolization, following which the aneurysm disappeared (Fig. 4).