Case Study 50
Edward D. Plowey
Case History
 The patient is a 2 year old girl with normal birth and
developmental histories who presented with new onset
seizures. A video EEG study confirmed complex partial
seizures arising from the left frontal lobe.
 The patient underwent an MRI of the brain.
Question 1
Describe the radiologic abnormality on the following MRI.
T2 FLAIR
T1
T1 post
contrast
Answer
 There is a 4 cm left cingulate gyrus lesion with heterogenous T2
FLAIR and T1 signal abnormalities involving the cortex and
subcortical white matter. The FLAIR abnormality focally involves
the corpus callosum and crosses the midline. The lesion is
surrounded by subtle edema and exerts mild mass effect that
expands the left cingulate gyrus and displaces the falx to the right
but shows no significant effect on the left frontal horn. No clear
contrast enhancement is seen.
 With involvement of the motor strip and the corpus callosum, the
lesion was deemed unresectable. A stereotactic needle biopsy
was performed.
Question 2
What is the differential diagnosis of this non-enhancing
flair lesion in a 2 year old child?
Answer
The differential diagnosis includes:
 dysembryoplastic neuroepithelial tumour
 ganglioglioma
 diffuse glioma, low grade
 Glioneuronal hamartoma
 The radiologic features are less favorable for pleomorphic
xanthoastrocytoma and meningioangiomatosis.
Question 3
Describe the findings and render a diagnosis for the
following intraoperative consultation smear preparation.
Answer
The intraoperative smear preparation shows a glial neoplasm
comprised of spindled cells with delicate bipolar cytoplasmic
processes. The nuclear chromatin is coarsely granular. There is
prominent gliovascular structuring. There are several entrapped
normal-appearing neurons. However, high grade features (mitotic
activity, endothelial hyperplasia, necrosis) are not seen.
Intraoperative Consultation Diagnosis:
A. Neoplastic.
B. Low grade glioma.
Question 4
 Describe the findings on the H&E stained permanent
sections of the stereotactic biopsy material.
 Click here to view virtual slide.
Answer
Histologic sections demonstrate a glial neoplasm with prominent
gliovascular structuring around vessels of variable caliber. A couple
of perivascular pseudorosettes are seen in the largest fragment. The
glioma cells show spindle nuclei with granular chromatin. No mitotic
figures are seen. Endothelial hyperplasia and necrosis are not seen.
There are numerous entrapped mature neurons in the tumor. No
binucleate neurons or phenotypically indeterminate cells are seen.
Question 5
 What immunostains will you order to further characterize this
neoplasm?
Answer
 GFAP (click hyperlink to view the virtual slide)
 EMA (click hyperlink to view the virtual slide)
 Ki67 (click hyperlink to view the virtual slide)
Question 6
 What further information to these immunostains convey?
Answer
A GFAP immunostain shows reactivity in tumor cell processes of
perivascular pseudorosettes and in reactive glial processes. An EMA
immunostain shows perivascular dot-like, microlumen-type
immunoreactivity in some of the tumor cells. A Ki67 immunostain
confirms a low proliferative index of less that 1%.
Question 7
 What is the final diagnosis?
Answer
Diagnosis: ANGIOCENTRIC GLIOMA, WHO GRADE 1.
Discussion
 Angiocentric glioma is new and rare entity in the WHO
Classification of Tumors of the Central Nervous System (2007).
Angiocentric glioma usually follows a benign clinical course. Most
reported cases have been treated with gross total or subtotal
resection; a couple of cases have been treated with radiation. In
some reported cases, excision of the lesion eliminated seizures.
Only 1 reported case has shown recurrence and progression to a
high grade glioma following resection.
 Wang et al. J Neuropathol Exp Neurol. 64:875-81, 2005.
 Preusser M et al. Am J Surg Pathol. 31:1709-18, 2007.
 The histogenesis of angiocentric glioma, which shows ependymal
features, is unknown. One group of authors has suggested a
radial glia origin (Preusser et al, 2007).
Discussion
 Angiocentric glioma occurs mostly in pediatric patients and young
adults, but has been reported in elderly adults, and is usually
associated with medically intractable epilepsy.
 A similar case of a frontoparietal angiocentric glioma in a 2 year old
child with seizures has been previously reported (J Child Neurol.
24:852-6, 2009.
 A recent retrospective study by Prayson (Pathology. 42:426-31, 2010)
estimates that angiocentric glioma underlies approximately 2% of
tumor-associated medically intractable seizures in pediatric patients.
 Given the non-resectable nature of the tumor in this case, the patient
has undergone radiation therapy. A 3 month interval MRI evaluation
demonstrated stable to a slight decrease in tumor size.