PPT - AJNR Blog
PPT - AJNR Blog
Yueh Z. Lee, MD/PhD
October 26, 2011
46 y/o female with history of NSCLC, who
presents with confusion. History of paraspinal
mass in right back/chest region, for which she
Pt transferred due to a mass found on head
Large frontal mass that had clearly invaded the
dura. Osseous invasion was also noted with
Large enhancing hyperdense mass, edema
Heterogenous mass with central necrosis
DDX - large solitary metastatic lesion,
Pre - CT
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
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
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
54 y/o female with intermittent bilateral facial
numbness. Workup demonstrated sellar/clival
Prior attempt at trans-sphenoidal biopsy
resulted in significant intra-op bleeding.
Destructive soft tissue mass extending from
sphenoid sinus with clival and sellar floor
Heterogenous enhancing lesion in the clivus
extending into the sphenoid sinuses. The lesion
abuts the pituitary gland with associated osseous
ACTH production adenoma as shown in
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.
Randomly distributed lesions throughout the
subcortical and deep white matter as above, with
cystic centers and peripheral enhancement
concerning for hematogenous spread of infection
Multifocal randomly distributed lesions
throughout the subcortical and deep white matter
Concerning for Balo’s concentric sclerosis
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
The tumefactive MS lesion is typically supratentorial and often presents with
hemiparesis, hemisensory loss, visual field defects, decreased consciousness, or
Imaging features include size of the lesion >2 cm, mass effect, edema, ring
enhancement, peripheral restriction on diffusion-weighted imaging (DWI), and venular
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
40 y/o male with a chroniic left facial paresis,
recently Multiple prior MRIs were negative.
Subsequent recent MR demonstrated a
geniculate ganglion mass.
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
lymphoma, or perineural spread of neoplasm, 1ry
Temporal Bone CT
Lesion centered at left geniculate ganglion with
Most likely DDx
Geniculate ganglion hemangioma
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
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