Image of the Month

The patient underwent initial precontrast computed tomography (CT) in the emergency department. This scan demonstrated a roughly 3-cm hyperdense mass that was centered on the right cavernous sinus. Associated vasogenic edema surrounded the mass. Additional foci of hypodensity were seen in the right centrum semiovale, said Dr. Gautam R. Mirchandani, director of neuroradiology at New York Methodist Hospital.

Pre- and postcontrast magnetic resonance imaging (MRI) on the next day demonstrated a heterogeneously—but avidly enhancing—extra-axial mass that corresponded with the CT finding. Regions of hypodensity seen on CT matched areas of restricted diffusion on diffusion-weighted imaging—representing acute infarction.

Magnetic resonance angiography (MRA) did not show the middle cerebral artery in that region because of the surrounding hypervascular lesion, which degrades the signal from that region. Flow-related enhancement was seen in more distal branches, suggesting that the middle cerebral artery was not occluded within the mass, but its branches were compromised. Of note, the regions of acute infarction correspond to the vascular territory of perforating vessels that arise from the proximal middle cerebral artery.

Further assessment of the mass was performed with CT angiography (CTA) to evaluate the relationship of the middle cerebral artery to the mass and to the regions of infarction. CTA demonstrated that the middle cerebral artery was not occluded within the lesion, although it was narrowed somewhat. Perforating vessels arising from the middle cerebral artery were also narrowed, likely causing her symptoms.

Based on the imaging characteristics, the clinical team was fairly confident that the avidly enhancing, extra-axial mass represented a meningioma, and surgical resection was planned.

Intraoperatively, frozen sections revealed histology consistent with adenocarcinoma, not with meningioma. Several specimens were sent to confirm this unexpected finding.

On postoperative review of the images, the two in-house neuroradiologists separately concurred that the imaging findings were still most consistent with a meningioma. “Even on re-review, I think it was reasonable to say that this looks like a meningioma,” said Dr. Mirchandani.

This conclusion was primarily based upon the extra-axial location and the avid enhancement. In addition, the tumor mass encased the near-by vessels, rather than occluding them. There was also no evidence of local osseous erosion, which is sometimes seen with other, more aggressive tumors. The absence of a known primary tumor made the possibility of a dural-based metastasis yet less likely.

Afterward, the patient was found to have a primary lung carcinoma, which had metastatically spread to the brain.

The patient arrested during the resection and underwent a prolonged resuscitation effort. She is currently intubated and on a ventilator. The patient is receiving supportive care, as she is still too ill for removal of the lung mass or undergo chemotherapy, said Dr. Susanna Horvath, director of the stroke program at New York Methodist Hospital.

“I think the teaching point in all this is that you have to look at the whole clinical scenario,” said Dr. Horvath.

By a large margin, enhancing, extra-axial masses represent meningiomas. Dural-based metastatic deposits, while possible, are seen much less often. Angiographic imaging can be very helpful in the evaluation of ischemic disease within the brain.

Precontrast CT shows a 3-cm mass near the right cavernous sinus.

Postcontrast T MRI shows the mass to be extra-axial and avidly enhancing. White matter hyperintensity corresponds to the hypodensity on CT.

DWI shows two foci of acute infarct on the right that are also visible on CT.

CTA demonstrates that the MCA within the mass is narrowed. Photos courtesy Dr. Gautam R. Mirchandani

The patient underwent initial precontrast computed tomography (CT) in the emergency department. This scan demonstrated a roughly 3-cm hyperdense mass that was centered on the right cavernous sinus. Associated vasogenic edema surrounded the mass. Additional foci of hypodensity were seen in the right centrum semiovale, said Dr. Gautam R. Mirchandani, director of neuroradiology at New York Methodist Hospital.

Pre- and postcontrast magnetic resonance imaging (MRI) on the next day demonstrated a heterogeneously—but avidly enhancing—extra-axial mass that corresponded with the CT finding. Regions of hypodensity seen on CT matched areas of restricted diffusion on diffusion-weighted imaging—representing acute infarction.

Magnetic resonance angiography (MRA) did not show the middle cerebral artery in that region because of the surrounding hypervascular lesion, which degrades the signal from that region. Flow-related enhancement was seen in more distal branches, suggesting that the middle cerebral artery was not occluded within the mass, but its branches were compromised. Of note, the regions of acute infarction correspond to the vascular territory of perforating vessels that arise from the proximal middle cerebral artery.

Further assessment of the mass was performed with CT angiography (CTA) to evaluate the relationship of the middle cerebral artery to the mass and to the regions of infarction. CTA demonstrated that the middle cerebral artery was not occluded within the lesion, although it was narrowed somewhat. Perforating vessels arising from the middle cerebral artery were also narrowed, likely causing her symptoms.

Based on the imaging characteristics, the clinical team was fairly confident that the avidly enhancing, extra-axial mass represented a meningioma, and surgical resection was planned.

Intraoperatively, frozen sections revealed histology consistent with adenocarcinoma, not with meningioma. Several specimens were sent to confirm this unexpected finding.

On postoperative review of the images, the two in-house neuroradiologists separately concurred that the imaging findings were still most consistent with a meningioma. “Even on re-review, I think it was reasonable to say that this looks like a meningioma,” said Dr. Mirchandani.

This conclusion was primarily based upon the extra-axial location and the avid enhancement. In addition, the tumor mass encased the near-by vessels, rather than occluding them. There was also no evidence of local osseous erosion, which is sometimes seen with other, more aggressive tumors. The absence of a known primary tumor made the possibility of a dural-based metastasis yet less likely.

Afterward, the patient was found to have a primary lung carcinoma, which had metastatically spread to the brain.

The patient arrested during the resection and underwent a prolonged resuscitation effort. She is currently intubated and on a ventilator. The patient is receiving supportive care, as she is still too ill for removal of the lung mass or undergo chemotherapy, said Dr. Susanna Horvath, director of the stroke program at New York Methodist Hospital.

“I think the teaching point in all this is that you have to look at the whole clinical scenario,” said Dr. Horvath.

By a large margin, enhancing, extra-axial masses represent meningiomas. Dural-based metastatic deposits, while possible, are seen much less often. Angiographic imaging can be very helpful in the evaluation of ischemic disease within the brain.

Precontrast CT shows a 3-cm mass near the right cavernous sinus.

Postcontrast T MRI shows the mass to be extra-axial and avidly enhancing. White matter hyperintensity corresponds to the hypodensity on CT.

DWI shows two foci of acute infarct on the right that are also visible on CT.

CTA demonstrates that the MCA within the mass is narrowed. Photos courtesy Dr. Gautam R. Mirchandani

The patient underwent initial precontrast computed tomography (CT) in the emergency department. This scan demonstrated a roughly 3-cm hyperdense mass that was centered on the right cavernous sinus. Associated vasogenic edema surrounded the mass. Additional foci of hypodensity were seen in the right centrum semiovale, said Dr. Gautam R. Mirchandani, director of neuroradiology at New York Methodist Hospital.

Pre- and postcontrast magnetic resonance imaging (MRI) on the next day demonstrated a heterogeneously—but avidly enhancing—extra-axial mass that corresponded with the CT finding. Regions of hypodensity seen on CT matched areas of restricted diffusion on diffusion-weighted imaging—representing acute infarction.

Magnetic resonance angiography (MRA) did not show the middle cerebral artery in that region because of the surrounding hypervascular lesion, which degrades the signal from that region. Flow-related enhancement was seen in more distal branches, suggesting that the middle cerebral artery was not occluded within the mass, but its branches were compromised. Of note, the regions of acute infarction correspond to the vascular territory of perforating vessels that arise from the proximal middle cerebral artery.

Further assessment of the mass was performed with CT angiography (CTA) to evaluate the relationship of the middle cerebral artery to the mass and to the regions of infarction. CTA demonstrated that the middle cerebral artery was not occluded within the lesion, although it was narrowed somewhat. Perforating vessels arising from the middle cerebral artery were also narrowed, likely causing her symptoms.

Based on the imaging characteristics, the clinical team was fairly confident that the avidly enhancing, extra-axial mass represented a meningioma, and surgical resection was planned.

Intraoperatively, frozen sections revealed histology consistent with adenocarcinoma, not with meningioma. Several specimens were sent to confirm this unexpected finding.

On postoperative review of the images, the two in-house neuroradiologists separately concurred that the imaging findings were still most consistent with a meningioma. “Even on re-review, I think it was reasonable to say that this looks like a meningioma,” said Dr. Mirchandani.

This conclusion was primarily based upon the extra-axial location and the avid enhancement. In addition, the tumor mass encased the near-by vessels, rather than occluding them. There was also no evidence of local osseous erosion, which is sometimes seen with other, more aggressive tumors. The absence of a known primary tumor made the possibility of a dural-based metastasis yet less likely.

Afterward, the patient was found to have a primary lung carcinoma, which had metastatically spread to the brain.

The patient arrested during the resection and underwent a prolonged resuscitation effort. She is currently intubated and on a ventilator. The patient is receiving supportive care, as she is still too ill for removal of the lung mass or undergo chemotherapy, said Dr. Susanna Horvath, director of the stroke program at New York Methodist Hospital.

“I think the teaching point in all this is that you have to look at the whole clinical scenario,” said Dr. Horvath.

By a large margin, enhancing, extra-axial masses represent meningiomas. Dural-based metastatic deposits, while possible, are seen much less often. Angiographic imaging can be very helpful in the evaluation of ischemic disease within the brain.

Precontrast CT shows a 3-cm mass near the right cavernous sinus.

Postcontrast T MRI shows the mass to be extra-axial and avidly enhancing. White matter hyperintensity corresponds to the hypodensity on CT.

DWI shows two foci of acute infarct on the right that are also visible on CT.

CTA demonstrates that the MCA within the mass is narrowed. Photos courtesy Dr. Gautam R. Mirchandani