A 23-year-old female with no significant medical history developed a
headache. On the evening of the following day, the headache was accompanied by
nausea and vomiting. Her mother discovered her having a seizure the following
morning and brought her immediately to the ED. She had another seizure and
vomited upon arrival to the ED, and shortly thereafter, she was sent for a
noncontrast head CT. An MRI was acquired 2 days later. Several days after these
imaging studies, the patient underwent surgery.
The noncontrast head CT demonstrates a large, roughly spherical, acute
hematoma in the left medial frontal lobe, near the falx cerebri, with
associated vasogenic edema (Figure 1). The frontal lobe cortex immediately
anterior and medial to the hematoma appears somewhat enlarged. MRI again
demonstrates the acute hematoma and vasogenic edema (Figure 2). Best seen on
the T2W images, there is abnormal signal intensity and mild expansion of the
frontal lobe cortex medial and anterior to the hematoma, corresponding to the
findings on the CT scan. On post-contrast images, there is a component of
abnormal enhancement along the medial aspect of the hematoma. The histology
slides show two distinct components of the abnormal tissue (Figure 3), one of
glial origin, the other sarcomatous.
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Figure1:
Axial noncontrast CT image of the brain shows a large hematoma in the left
frontal lobe. The hematoma contains components of varying density, suggesting
blood products of slightly varying age. There is abnormal hypodensity in the
white matter surrounding the hematoma (short white arrows), consistent with
vasogenic edema. The medial frontal lobe cortex adjacent to the hematoma is
slightly thickened (long black arrows) compared with the contralateral
side.
Photos courtesy of M. Ghesani
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Figure 2.
Axial MRIs of the brain. The hematoma seen on the CT scan is predominantly
hypointense to gray matter in the T2W image (A), and isointense on the
noncontrast T1W image (C), consistent with acute parenchymal blood products.
Also corresponding to CT findings, the adjacent medial frontal cortex is
abnormally thickened. This abnormal cortex has abnormal T2 signal
hyperintensity (white arrows in A) and heterogeneous enhancement in the
postcontrast T1W image (white arrows in B), consistent with neoplasm. There is
abnormal T2 signal hyperintensity in the white matter surrounding the hematoma
on the T2W image, hypointense on the T1W images (black arrows in A, B and
C).
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There is a wide range in the reported frequency of acute intracranial
hemorrhage as the initial presentation of cerebral neoplasm, between 9% and
42%. In the absence of trauma history, there are some radiologic and clinical
features of acute intracranial hemorrhage that may raise suspicion of an
underlying lesion such as a neoplasm or vascular malformation.
The degree of vasogenic edema surrounding an acute hematoma with
underlying neoplasm may be more pronounced, at initial imaging, than in the
setting of bland hemorrhage. Bland hemorrhage is commonly seen in the setting
of hypertension and typically located in the basal ganglia region. Lobar
hemorrhages such as those seen in the setting of amyloid angiopathy usually
affect elderly patients. Hemorrhage may present acutely in the setting of
venous sinus thrombosis and associated venous infarct. This patient is
relatively young, and the hemorrhage is in an uncommon location. Despite
proximity of the hematoma to the falx, there is no radiologic evidence of
superior sagittal sinus thrombosis. Nor are there any abnormal flow voids to
suggest an arteriovenous malformation. Most importantly, there is abnormal
enhancing tissue within the medial aspect of the frontal lobe cortex, adjacent
to the hematoma on the post-contrast MRI, suspicious for a high-grade glial
tumor. The mass was resected, and the histology of the medial frontal lobe mass
was consistent with gliosarcoma.
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Figure 3. Histologic
slides of glial (A) and sarcomatous (B) components of the gliosarcoma. The
glial component (shown at 40X) features giant multinucleated anaplastic cells.
There are multiple atypical mitoses (black arrows). The sarcomatous component
(shown at 20X) is composed of fascicles of spindle-shaped cells.
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The specific imaging characteristics of gliosarcoma may include a
heterogeneously enhancing mass. There may be dural invasion, depending on the
location of the tumor. On CT, gliosarcoma can appear as a large necrotic mass
with heterogeneous contrast enhancement mimicking glioblastoma. Another variant
can appear as a hyperdense lesion with well-defined margins and homogeneous
enhancement. There are few detailed descriptions of the MRI appearance of
gliosarcoma, as many of the case series were published before the widespread
use of MRI. However, foci of hemorrhage and necrosis have been described in
gliosarcoma, as well as marked peritumoral edema and heterogeneous appearance
on T1 and T2 weighted images.
Gliosarcoma is a rare glioblastoma variant that features glial and
mesenchymal components, accounting for approximately 2% of all glioblastoma.
WHO describes gliosarcoma as a well-circumscribed lesion with clearly
identifiable biphasic glial and metaplastic mesenchymal components. Gliosarcoma
has been described as being most common in the temporal lobe. Other small
series cite the frontal lobe as the most common location. Gliosarcoma is almost
never infratentorial in location. The histiogenesis of gliosarcoma is
uncertain, and there are several theories in the literature for the origins of
the sarcomatous component.
Gliosarcoma presents most commonly between the 4th through 7th decades
with a male-to-female predominance of 2:1. Presenting symptoms are similar to
those of any space-occupying lesion and include aphasia, headache, seizures and
cognitive decline. Similar to glioblastoma multiforme, gliosarcoma has a poor
prognosis, due mainly to the high frequency of local recurrence. If untreated,
the prognosis is approximately 4 months. There is a slightly better prognosis
with treatment, approximately 6 to 10 months. Compared with glioblastoma,
extracranial metastases from gliosarcoma occur more frequently and are often
found to have only the sarcomatous components. Metastases to cervical lymph
nodes, spleen, skin, adrenal glands, kidneys, oral mucosa, bone marrow, skull,
ribs and the spine have all been reported.
Munir Ghesani, MD, is an attending radiologist at St.
Luke’s-Roosevelt Hospital Center, and Beth Israel Medical Center and a
HemOnc Today section editor. He is an associate clinical professor of radiology
at Columbia University College of Physicians and Surgeons.
Lauren Moomjian, MD, is a radiology resident at St
Luke’s-Roosevelt Hospital Center, New York.
Daniel Meltzer, MD is an assistant attending physician in radiology
at St Luke-Roosevelt Hospital Center and Beth Israel Medical Center and
Assistant Professor of Clinical Radiology at Albert Einstein College of
Medicine, New York.
For more information:
- Han SJ. J Neurooncol. 2010;96:313-320.
- Koul R. J HK Coll Radiology. 2008;11:116-121.
- Meis JM. Cancer. 1991;67:2342-2348.
- Pakos EE. J Neurooncol. 2005;74:301-304.
- Schrader B. Acta Neurochir (Wien). 2000;142:979-985.