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Neurofibromatosis type 2

Case contributed by Bruno Di Muzio
Diagnosis certain

Presentation

Known history of neurofibromatosis.

Patient Data

Age: 20 years
Gender: Female

MRI Brain (10 years ago)

mri

Multiple meningiomas: right frontal parafalcine, right parietal convexity, left trigone, left sphenoidal wing meningioma, and left cerebellar convexity.

Bilateral acoustic neuromas.

mri

The previous right frontal and right retrosigmoid craniotomies are noted.

Multiple extra-axial masses are again noted, best evaluated on the T2 weighted imaging:

  • meningioma right parietal (stable)
  • multiple nodular meningiomas along the falx, particularly on the right, deep to the previous craniotomy
  • left acoustic schwannomas: with cystic components (similar in size to before)
  • stable soft tissue noted at the site of the previous right acoustic schwannoma excision
  • left parafalcine occipital lesion measures (stable)
  • mass adjacent to the right middle frontal gyrus has substantially increased in size

The ventricular configuration remains unremarkable. The optic nerves are grossly normal. No regions of restricted diffusion.

Conclusion:  Substantial serial growth of the right frontal lobe meningioma. The remainder of the extra-axial masses remain stable.

mri

In the cervical spine, there is a previous laminectomy at C5 to C7 levels. The spinal cord shows a central stable cleft at C7. This appears to be the main intramedullary lesion. Normal spinal cord size. In the spinal canal, the intradural nodule at posterior C1 level is stable measures 9 x 4 cm in size. In the lower cervical spine, the prominent dorsal root ganglia at bilateral C5, the large right C6 and left C8 foraminal/extraforaminal nerve sheath tumors are stable. Bilateral T1 nerve sheath tumors are stable. In the lumbar spine, numerous tiny small T2 hypointense nodules in the cauda equina are stable. Left L2 foraminal/extraforaminal nerve sheath tumor is stable. The right lumbar plexus nerve sheath tumor centered at L3 level, between psoas and quadratus lumborum is stable.

mri

Dffuse dural thickening and enhancement with multiple areas of nodular thickening and durally based masses compatible with extensive meningiomatosis.

There is a bulky disease involving the falx cerebrum, the largest component at the vertex measuring 3.8 x 2.6 x 3.9 cm, and that the left posterior parafalcine region measuring 3 x 2.1 x 5.1 cm. Tumor extensively invades and occludes the superior sagittal sinus. A non-dominant right transverse sinus and sigmoid sinus are patent.

Further bulky meningioma is centered on an expanded left cavernous sinus, bulging laterally into the middle cranial fossa, medially to involve the sella, inferiorly into the left sphenoid sinus, and posteriorly into Meckel's cave. Abnormal enhancing tumor extends through the right superior and inferior orbital fissures to involve the orbital apex and cause mild left proptosis. There is also involvement of pterygopalatine fossa, and tumor extending into the left foramen ovale. Cavernous carotid flow-voids are maintained.

Of note, there bilateral vestibular schwannomas.

Conclusion: Extensive meningiomatosis, with bulky disease along the falx with superior sagittal sinus invasion/occlusion, and a large left cavernous sinus meningioma involving skull base foramina in the orbital apex.

pathology

MICROSCOPIC DESCRIPTION: Sections show a tumor demonstrating histological features of both schwannoma and meningioma. The schwannoma component shows areas composed of short fascicles of tumor cells (Antoni A) with focal nuclear pallisading (Verocay bodies) and loose fibrillary areas (Antoni B). Tumor cells contain bland wavy nuclei with inconspicuous nucleoli.

The meningioma component shows a moderately hypercellular meningioma with a well-developed syncytial architecture. Focal psammomatous calcifications are present. Tumor cells demonstrate uniform nuclear features.

Focal dural attachment and bone invasion is noted. No mitoses, necrosis or brain invasion are seen.

Immunohistochemical results confirm a S100+ schwannoma component andEMA+ meningioma component. The progesterone receptor immunostain is  positive within both components.

DIAGNOSIS: Collision tumor (schwannoma and meningioma WHO grade I).

Case Discussion

Neurofibromatosis type 2 is defined by the presence of multiple meningiomas, schwannomas and/or ependymomas. 

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