Cavernous hemangiomas and cavernomas are vascular tumors with nearly similar pathophysiologies,
and they have been labeled interchangeably in the past but have a few subtle differences.[1] They are benign tumors, most commonly intraparenchymal. Extra-axial cavernous hemangiomas
account for only 0.4 to 2% of all intracranial vascular malformations.[2] Extra-axial cavernous hemangiomas most commonly arise in the middle cranial fossa
in or near the cavernous sinus.[3] Other locations such as the convexity, posterior fossa, and anterior cranial fossa
are very rare.[4] Only 15 cases of convexity-based dural cavernous hemangiomas have been reported
till date ([Table 1]). The most common differential diagnosis of a well-defined, dural-based tumor is
a convexity meningioma. We hereby report a case of large dural-based frontal convexity
cavernous hemangioma mimicking a convexity meningioma.
Table 1
Literature review of reported cases of dural-based convexity cavernous hemangiomas
|
Authors
|
Year
|
Site
|
Age (y)/Sex
|
Seizures
|
Hemorrhage
|
Headache
|
Neurologic deficits
|
Treatment
|
|
Source: Modified with permission from Di Vitantonio et al.[19]
|
|
Ito et al
|
1978
|
Parietal convexity
|
NR
|
NR
|
NR
|
NR
|
NR
|
NR
|
|
Kunishio et al
|
1986
|
NR
|
61/F
|
No
|
No
|
No
|
Yes
|
Surgery
|
|
Perry et al
|
1993
|
Parietal convexity
|
77/F
|
Yes
|
No
|
No
|
No
|
Surgery
|
|
Revuelta et al
|
1994
|
Occipital convexity
|
66/M
|
No
|
No
|
Yes
|
No
|
Surgery
|
|
Lewis et al
|
1994
|
Parietal convexity
|
36/F
|
No
|
No
|
Yes
|
Yes
|
Surgery
|
|
Suzuki et al
|
1996
|
Frontal convexity
|
78/F
|
No
|
Yes
|
No
|
Yes
|
Surgery
|
|
Hyodo et al
|
2000
|
Parieto-occipital convexity
|
77/M
|
No
|
No
|
No
|
Yes
|
Surgery
|
|
Shen et al
|
2000
|
Parietal convexity
|
18/F
|
No
|
No
|
Yes
|
Yes
|
Surgery
|
|
McKechnie et al
|
1998
|
Occipital convexity
|
47/F
|
No
|
No
|
NO
|
Yes
|
Surgery
|
|
Hwang et al
|
2009
|
Frontal convexity
|
61/M
|
No
|
Yes
|
Yes
|
Yes
|
Surgery
|
|
Joshi et al
|
2009
|
Parieto-occipital convexity
|
15/M
|
No
|
No
|
Yes
|
No
|
Surgery
|
|
Sakakibara et al
|
2010
|
Frontoparietal convexity
|
59/M
|
No
|
No
|
No
|
Yes
|
Surgery
|
|
Yonezawa et al
|
2014
|
NR
|
78/F
|
No
|
No
|
Yes
|
No
|
Surgery
|
|
Di Vitantonio H et al
|
2015
|
Frontal convexity
|
30/F
|
No
|
No
|
Yes
|
No
|
Surgery
|
|
Pelluru et al
|
2018
|
Temporoparietal convexity
|
26/M
|
Yes
|
No
|
No
|
No
|
Surgery
|
A 22-year-old woman presented with complaints of five episodes of seizures since 4
months and headache since 3 months. The seizures were partial in onset involving left
side of the body with secondary generalization. At admission, the patient was conscious,
oriented, and obeying commands with a Glasgow coma scale of 15 points. There were
no neurodeficits. Computed tomography (CT) scan was performed, which showed a contrast-enhancing,
dural-based, homogenous, well-circumscribed lesion having a maximum diameter of 5.5
cm in the right frontal convexity ([Fig. 1]). On magnetic resonance imaging (MRI), the lesion was found to be isointense on
T1 and homogenously hyperintense on T2 with brilliant postcontrast enhancement. However,
there was no obvious dural tail sign, and the central core of the lesion showed increased
T2 intensity than the periphery of the tumor ([Fig. 1]). There was also perilesional edema with significant mass effect. On imaging studies,
a provisional diagnosis of a frontal convexity meningioma was made. The patient was
planned for right frontal craniotomy and Simpson's grade 1 resection of the lesion.
Intraoperatively it was observed that the tumor was adherent to the convexity dura
mater. The tumor was extremely vascular, reddish brown, with adequate plane between
the tumor and the surrounding edematous parenchyma with small arterial feeders and
areas of adhesions. The tumor was excised en bloc, and tumor resection was confirmed
on postoperative CT scan ([Fig. 2]). Unlike a convexity meningioma, the tumor did not lose its vascularity even after
disconnecting the involved dural island from the surrounding dura mater. On histopathologic
analysis, the tumor showed varying sized blood vessels with intraluminal red cells
on an acellular hyalinized stromal background ([Fig. 3]). On immunohistochemistry, the tumor cells were CD34-positive suggesting an endothelial
origin. There were occasional foci of dystrophic calcification. The diagnosis of a
cavernous hemangioma was confirmed. The patient had an uneventful postoperative course
and is seizure free for the past 2 years. Follow-up imaging has shown no residual
lesion or recurrence.
Fig. 1 Preoperative radiological imaging (CT and MRI) showing a well-circumscribed, contrast-enhancing,
dural-based lesion in the right frontal region.
Fig. 2 Postoperative CT scan axial image showing complete excision of the lesion.
Fig. 3 Pathology specimen (A) and the postoperative hematoxylin and eosin stain slides (B) of the cavernous hemangioma.
Cavernous malformations belong to a spectrum of vascular malformations wherein the
vasculature forms cisterns or caverns without a proper medial and adventitial wall
to these cisterns leading to chances of recurrent hemorrhages within these malformations.
They account for 10 to 15% of all central nervous system vascular anomalies.[1] Two separate entities have been included in the spectrum of cavernous malformations:
cavernomas and cavernous hemangiomas. Cavernomas tend to be familial, multiple, with
perilesional hemosiderin rings and higher hemorrhagic propensity as compared with
cavernous hemangiomas. Therefore, cavernomas present most commonly with sequelae of
bleeding like seizures and focal neurologic deficits, whereas cavernous hemangiomas
can go unnoticed until they reach large sizes and cause mass effect.[1] The most common location for cavernomas is supratentorial and intraparenchymal.[1] The pathologic hallmarks of cavernomas are the presence of sinusoids with a single
layer of endothelium and thin collagenous wall with lack of smooth muscle fibers and
elastic fibers. There are classic leaky sinusoids with hemosiderin staining and gliotic
reaction in the adjacent brain.[5] Cavernous hemangiomas, on the other hand, most commonly occur in the middle cranial
fossa and sellar region, in close relation with the cavernous sinus. Cavernous hemangiomas
of the cavernous sinus have been classified histopathologically into two subgroups
based on operative findings: type A, having thin-walled vascular channels, associated
with severe bleeding and type B, having well-formed vessels with solid parenchyma.
The hemosiderin rings give cavernomas the classic “popcorn” or “berry” appearance
due to loss of signal. The T1- and T2-weighted signals vary depending on the age of
the hemorrhage. Gradient echo and susceptibility-weighted images can detect small,
multiple cavernomas with higher sensitivity.[6] In contrast, cavernous hemangiomas are hypointense on T1-weighted, uniformly hyperintense
on T2-weighted imaging and show brilliant gadolinium contrast enhancement. The lack
of hemosiderin-ring signal loss and the occasional presence of a dural tail with dural
base can be misleading. After review of the literature, only 15 cases of dural-based
convexity cavernous hemangiomas have been reported in literature.[1]
[2]
[3]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19] ([Table 1]). Cases of extracranial temporalis muscle cavernous hemangiomas have been reported
before.[20] Most cases reported were diagnosed as convexity meningiomas, due to their similar
radiologic features. In the reported cases, there was only slightly higher female
prevalence (8:7). Eight patients were older than 60 years, whereas only two cases
were reported younger than 20 years of age. Only two cases reported seizures as the
presenting features, and only two cases had hemorrhage as an imaging finding. All
reported patients have undergone surgery.
All current evidence indicates that treatment of choice for these lesions is total
surgical removal. However, like any other vascular malformation, stereotactic radiosurgery
represents a therapeutic option. Cavernous hemangiomas in the middle fossa can be
challenging because of their location and high vascular supply, and hence preoperative
radiation and embolization are recommended to reduce operative complications.[7]
[12] However, because the working diagnosis of a convexity meningioma is mostly made
before operating these tumors, surgery has been performed without any preoperative
intervention in most cases. Simpson's grade 1 removal with resection of the involved
dura is recommended for these tumors. On suspicion that the tumor may not actually
be a meningioma during surgery, it is imperative that the tumor be excised as whole,
because the risk of bleeding is much higher than in a meningioma. The tumor capsule
should be left intact. Careful coagulation of the exposed part of the tumor can help
shrink the tumor and separate it from the adjoining parenchyma. In cases in which
complete removal is not possible, it is advisable to treat the lesion with radio surgery
after histopathologic confirmation.[2]
[12] Complete resection of the tumor is possible with minimal blood loss and appears
to be curative.[10] A possibility of a cavernous hemangioma should be kept in mind when a radiologic
diagnosis of a convexity meningioma is made. Unlike cavernomas that have a propensity
of recurrent hemorrhage, cavernous hemangiomas are clinically silent until they attain
a large size and usually present with mass effect. Complete resection of these lesions
is the treatment of choice. Breach in the tumor capsule should be avoided during surgery,
as these tumors are highly vascular.
