UNCNeuro RadPath

ConferenceYueh Z. Lee, MD/PhD

October 26, 2011

Case #1

46 y/o female with history of NSCLC, who presents with confusion. History of paraspinal mass in right back/chest region, for which she received chemoradiation.

Pt transferred due to a mass found on head CT.

Operative Findings: Large frontal mass that had clearly invaded the

dura. Osseous invasion was also noted with hyperostotic effects.

Imaging Findings

CT Large enhancing hyperdense mass, edema Central necrosis

MRI Heterogenous mass with central necrosis

DDX - large solitary metastatic lesion, meningioma, hemangiopericytoma

Pre - CT Post- CT

T2 Pre –T1 Post T1

rCBV

CD99 IHC

Ewing sarcoma / peripheral PNET (p-PNET)

• Ewing sarcoma and peripheral PNET (p-PNET) are round cell sarcomas that show varying degrees of neuroectodermal differentiation and have characteristic molecular genetic abnormalities.

• Ewing sarcoma/p-PNET rarely involves the CNS.

• The molecular genetic abnormalities are chromosomal translocations involving a fusion of the EWS gene with a member of the Ets family of transcription factors, which leads to the expression of their chimeric fusion oncoproteins.

• These characteristic translocations are not found in central PNET. The common molecular abnormalities in c-PNET include isochromosome 17q and myc gene amplifications in patients with medulloblastoma or less commonly, supratentorial PNET. (Kazmi et al. Diagn Mol Pathol 2007;16:108–111)

• It is important to distinguish peripheral and central PNETs, since they are biologically different entities.

Kazmi et al. Diagn Mol Pathol 2007;16:108–111

Case #2

54 y/o female with intermittent bilateral facial numbness. Workup demonstrated sellar/clival lesion.

Prior attempt at trans-sphenoidal biopsy resulted in significant intra-op bleeding.

Imaging Findings

CT Destructive soft tissue mass extending from

sphenoid sinus with clival and sellar floor destruction

MR Heterogenous enhancing lesion in the clivus

extending into the sphenoid sinuses. The lesion abuts the pituitary gland with associated osseous destruction.

Non-con CT

T2

Post-T1 Post-T1

ACTH production adenoma as shown in immunohistochemistry stain

Case #3

56 y/o male presents with dysarthria and LUE weakness, right facial droop. His exam stabilized, and he was discharged with close follow-up. Approximately 1 week later, he was readmitted with worsening symptoms.

Case #3 Initial MRI

Randomly distributed lesions throughout the subcortical and deep white matter as above, with cystic centers and peripheral enhancement concerning for hematogenous spread of infection or metastases.

“Final” MRI Multifocal randomly distributed lesions

throughout the subcortical and deep white matter Concerning for Balo’s concentric sclerosis

Initial MRI

FLAIR Post T1

Subsequent MRI

T2 FLAIR Post –T1

Post –T1

Tumefactive Demyelinating Disease

• Tumefactive MS — presentation of MS lesion as a large mass lesion that mimics a neoplasm clinically and radiologically.

• Neurologic abnormaliites depends on size and location of lesion and may be subacute or chronic.

• The tumefactive MS lesion is typically supratentorial and often presents with hemiparesis, hemisensory loss, visual field defects, decreased consciousness, or seizures.

• Imaging features include size of the lesion >2 cm, mass effect, edema, ring enhancement, peripheral restriction on diffusion-weighted imaging (DWI), and venular enhancement.

• Most patients with tumefactive MS go on to develop typical relapsing-remitting MS. Monophasic cases occur but are uncommon.

• The pathogenesis of tumefactive MS is unknown. It has been suggested that tumefactive MS falls within the spectrum of MS rather than being an intermediate entity between MS and ADEM or a distinct variant of MS.

Wu and Lucchinetti. Semin Immunopathol (2009) 31:439–453

Case #4

40 y/o male with a chroniic left facial paresis, recently Multiple prior MRIs were negative. Subsequent recent MR demonstrated a geniculate ganglion mass.

Imaging Findings

MR Enhancing lesion seen at the level of the left

geniculate ganglion. Contiguous spread of enhancement to the lateral wall of the ipsilateral cavernous sinus and dura of the middle cranial fossa.

DDx lymphoma, or perineural spread of neoplasm, 1ry

tumor

T2

Post –T1

Post –T1

Imaging Findings

Temporal Bone CT Lesion centered at left geniculate ganglion with

stippled calcifications. Most likely DDx

Geniculate ganglion hemangioma

Non-con CT

Hemangioma of the Geniculate Ganglion (GG)

• Incidence was 0.7% in a series of1,430 intratemporal bone vascular tumors.

• Historically termed “hemangioma,” but now thought to represent a venous malformation rather than a true neoplasm.

• Speculated to arise from the rich vascular network surrounding the GG. This vascular network receives its blood supply from the petrosal artery, which is a branch of the middle meningeal artery.

• Geniculate ganglion hemangiomas present with facial nerve dysfunction at an early stage.

• Because of the relative disparity between the facial nerve dysfunction and the small size of the hemangioma, it is suggested that some of the nerve dysfunction may be due to vascular steal and nerve ischemia.

.Semaan et al. Otol Neurotol 31:665Y670, 2010