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Two cases of pineal-region meningiomas derived from arachnoid membrane over the vein of Galen without dural attachment.

Inoue A, Ohnishi T, Kohno S, Ohtsuka Y, Nakamura Y, Mizuno Y, Kitazawa R, Ohue S - World J Surg Oncol (2015)

Bottom Line: Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus.Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus.We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Ehime University School of Medicine, 454 Shitsukawa, Toon, Ehime, 791-0295, Japan. iakihiro3@gmail.com.

ABSTRACT

Background: We present two rare cases of pineal-region meningiomas. These tumors are the first reported cases of dura-unrelated meningiomas originating from the arachnoid membrane over the vein of Galen (AMG).

Case description: In Case 1, a 37-year-old woman presented with a progressing headache. Magnetic resonance imaging (MRI) showed a large tumor in the pineal region, displacing the vein of Galen upward. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus. In Case 2, a 67-year-old man presented with dizziness. MRI demonstrated a large mass in the pineal region, displacing the vein of Galen inferiorly. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus. Both tumors were totally excised (Simpson Grade III for Case 1, Grade I for Case 2) via a left occipital transtentorial approach. No dural attachment was recognized in either case, but the tumor in Case 1 was firmly adherent to the inferior portion of the AMG, while that in Case 2 was attached to the superior portion of the AMG, but remained dissectible.

Conclusions: We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment. These tumors can be totally resected by careful dissection of the tumor from the arachnoid membrane surrounding the vein of Galen.

No MeSH data available.


Related in: MedlinePlus

Radiological imaging of the tumor in the pineal region in Case 1. a, b Gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) in Case 1 shows a well-defined tumor within the quadrigeminal cistern, compressing the dorsal part of the midbrain with resulting mild hydrocephalus (a, axial view, b sagittal view). The vein of Galen (white arrow) and splenium of the corpus callosum (white asterisk) are displaced upward and the pineal body cannot be identified. c, d Preoperative internal cerebral angiography (ICAG) shows occlusion of the vein of Galen and development of a large collateral venous channel (white arrowhead) on the right medial surface of the occipital lobe, draining into the superior sagittal sinus (c, right venous phase, d left venous phase)
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Fig1: Radiological imaging of the tumor in the pineal region in Case 1. a, b Gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) in Case 1 shows a well-defined tumor within the quadrigeminal cistern, compressing the dorsal part of the midbrain with resulting mild hydrocephalus (a, axial view, b sagittal view). The vein of Galen (white arrow) and splenium of the corpus callosum (white asterisk) are displaced upward and the pineal body cannot be identified. c, d Preoperative internal cerebral angiography (ICAG) shows occlusion of the vein of Galen and development of a large collateral venous channel (white arrowhead) on the right medial surface of the occipital lobe, draining into the superior sagittal sinus (c, right venous phase, d left venous phase)

Mentions: A 37-year-old woman visited our department after experiencing a gradually worsening headache over a 6-month period. On admission, she presented with headache and altered mental status. Brain computed tomography (CT) and gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed a homogeneously enhanced and well-defined tumor (diameter, 30 × 30 × 25 mm) in the pineal region. The tumor was located in the inferior portion of the vein of Galen, compressing the vessel upward. The splenium of the corpus callosum was also displaced superiorly (Fig. 1). Bilateral internal cerebral angiography (ICAG) revealed that apparent arterial supply was not visualized. The vein of Galen was occluded, and an upward shift of bilateral internal cerebral veins (ICVs) was not confirmed. Collateral venous flow drained through veins on the right medial surface of the occipital lobe to the superior sagittal sinus. Tumor resection was performed using a left occipital transtentorial approach (OTA). When the cerebellar tentorium was incised along the straight sinus to the free edge, a very thick and cloudy arachnoid membrane came into view, making it difficult to dissect the tumor from the vein of Galen and its tributaries. No dural attachment was seen at the falcotentorial junction or free edge of the tentorium. The tumor was firmly adherent to the inferior portion of the vein of Galen (Fig. 2a, b). The tumor was easily dissected from surrounding structures, including the brainstem, but we could not free the tumor from the attachment site that firmly adhered to the inferior thick wall surrounding the vein of Galen, resulting in a “Simpson Grade III” resection. Histological examination showed transitional meningioma, and Ki-67 (MIB-1) labeling index was low (2.6 %) (Fig. 2c). The headache was improved immediately after surgery, and no other abnormalities were identified. MRI at 3 months postoperatively did not show any tumor (Fig. 2d), and mental activity returned to near-normal. As of the time of writing, 1 year after surgery, the patient remains healthy without tumor recurrence.Fig. 1


Two cases of pineal-region meningiomas derived from arachnoid membrane over the vein of Galen without dural attachment.

Inoue A, Ohnishi T, Kohno S, Ohtsuka Y, Nakamura Y, Mizuno Y, Kitazawa R, Ohue S - World J Surg Oncol (2015)

Radiological imaging of the tumor in the pineal region in Case 1. a, b Gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) in Case 1 shows a well-defined tumor within the quadrigeminal cistern, compressing the dorsal part of the midbrain with resulting mild hydrocephalus (a, axial view, b sagittal view). The vein of Galen (white arrow) and splenium of the corpus callosum (white asterisk) are displaced upward and the pineal body cannot be identified. c, d Preoperative internal cerebral angiography (ICAG) shows occlusion of the vein of Galen and development of a large collateral venous channel (white arrowhead) on the right medial surface of the occipital lobe, draining into the superior sagittal sinus (c, right venous phase, d left venous phase)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4513678&req=5

Fig1: Radiological imaging of the tumor in the pineal region in Case 1. a, b Gadolinium-enhanced T1-weighted magnetic resonance imaging (MRI) in Case 1 shows a well-defined tumor within the quadrigeminal cistern, compressing the dorsal part of the midbrain with resulting mild hydrocephalus (a, axial view, b sagittal view). The vein of Galen (white arrow) and splenium of the corpus callosum (white asterisk) are displaced upward and the pineal body cannot be identified. c, d Preoperative internal cerebral angiography (ICAG) shows occlusion of the vein of Galen and development of a large collateral venous channel (white arrowhead) on the right medial surface of the occipital lobe, draining into the superior sagittal sinus (c, right venous phase, d left venous phase)
Mentions: A 37-year-old woman visited our department after experiencing a gradually worsening headache over a 6-month period. On admission, she presented with headache and altered mental status. Brain computed tomography (CT) and gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed a homogeneously enhanced and well-defined tumor (diameter, 30 × 30 × 25 mm) in the pineal region. The tumor was located in the inferior portion of the vein of Galen, compressing the vessel upward. The splenium of the corpus callosum was also displaced superiorly (Fig. 1). Bilateral internal cerebral angiography (ICAG) revealed that apparent arterial supply was not visualized. The vein of Galen was occluded, and an upward shift of bilateral internal cerebral veins (ICVs) was not confirmed. Collateral venous flow drained through veins on the right medial surface of the occipital lobe to the superior sagittal sinus. Tumor resection was performed using a left occipital transtentorial approach (OTA). When the cerebellar tentorium was incised along the straight sinus to the free edge, a very thick and cloudy arachnoid membrane came into view, making it difficult to dissect the tumor from the vein of Galen and its tributaries. No dural attachment was seen at the falcotentorial junction or free edge of the tentorium. The tumor was firmly adherent to the inferior portion of the vein of Galen (Fig. 2a, b). The tumor was easily dissected from surrounding structures, including the brainstem, but we could not free the tumor from the attachment site that firmly adhered to the inferior thick wall surrounding the vein of Galen, resulting in a “Simpson Grade III” resection. Histological examination showed transitional meningioma, and Ki-67 (MIB-1) labeling index was low (2.6 %) (Fig. 2c). The headache was improved immediately after surgery, and no other abnormalities were identified. MRI at 3 months postoperatively did not show any tumor (Fig. 2d), and mental activity returned to near-normal. As of the time of writing, 1 year after surgery, the patient remains healthy without tumor recurrence.Fig. 1

Bottom Line: Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus.Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus.We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Ehime University School of Medicine, 454 Shitsukawa, Toon, Ehime, 791-0295, Japan. iakihiro3@gmail.com.

ABSTRACT

Background: We present two rare cases of pineal-region meningiomas. These tumors are the first reported cases of dura-unrelated meningiomas originating from the arachnoid membrane over the vein of Galen (AMG).

Case description: In Case 1, a 37-year-old woman presented with a progressing headache. Magnetic resonance imaging (MRI) showed a large tumor in the pineal region, displacing the vein of Galen upward. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the veins on the right medial surface of the occipital lobe to the superior sagittal sinus. In Case 2, a 67-year-old man presented with dizziness. MRI demonstrated a large mass in the pineal region, displacing the vein of Galen inferiorly. Angiography disclosed occlusion of the vein of Galen, with deep venous flow draining through the collateral venous channel into the transverse sinus. Both tumors were totally excised (Simpson Grade III for Case 1, Grade I for Case 2) via a left occipital transtentorial approach. No dural attachment was recognized in either case, but the tumor in Case 1 was firmly adherent to the inferior portion of the AMG, while that in Case 2 was attached to the superior portion of the AMG, but remained dissectible.

Conclusions: We reported two cases of pineal-region meningiomas originating from the arachnoid membrane over the vein of Galen, resulting in meningioma without dural attachment. These tumors can be totally resected by careful dissection of the tumor from the arachnoid membrane surrounding the vein of Galen.

No MeSH data available.


Related in: MedlinePlus