Key-words:
Cavernous venous malformations - idiopathic orbital inflammation - orbital
Introduction
Cavernous venous malformations (CVMs) of the orbit, formerly known as orbital cavernous
hemangiomas, are the most common, primary, orbital lesions of adults.[[1]] CVMs occur more often in middle-aged women.[[2]] Typically, orbital CVMs are slow-growing and noninfiltrative lesions. The most
common presenting complaints are retrobulbar or periorbital pain and visual loss,[[2]] while the most common presenting sign is proptosis. CVMs are usually located in
the intraconal space.[[2]]
We report a rare case of a bilateral orbital CVM with an intralesional hemorrhage
in the left eye mimicking an idiopathic orbital inflammation.
Case Report
A 60-year-old woman presented with severe headache and visual loss in the left eye
for 2 days. Initially having the headache at the left temporal region and around the
left eye, she had developed the visual loss in the left eye after a few hours. The
patient denied having pain on eye movement, fever, jaw claudication, or weight loss.
She also reported no history of autoimmune diseases or recent trauma.
The patient went to her primary care hospital. A computed tomography (CT) scan of
the orbit revealed a left orbital-apex mass adhering to the left superior rectus and
medial rectus muscles and a right orbital apex mass [[Figure 1]]. She was diagnosed as having an orbital pseudotumor and was referred to our hospital
for further management. Her visual acuity in the right eye was 20/40 and counting
fingers in the left eye. An eye examination found a relative afferent pupillary defect
as well as a mild limitation of the lateral rectus movement in the left eye. There
was no lid swelling or proptosis, and the fundus and disc appeared normal. We observed
that the patient also had a blue–green soft nodule on her left cheek [[Figure 2]]. We reviewed her CT scan and noticed a homogeneous lesion on her left cheek [[Figure 3]]. Consequently, we thought the cheek lesion might be a hemangioma related to her
orbital lesions. We requested magnetic resonance imaging (MRI) of the brain and orbit.
Figure 1: The computed tomography scan of the orbit showed a homogeneous, enhancing mass at
the left orbital apex (Fig 1.a) adhering to the left superior rectus (Fig1.b) and
medial rectus muscles (Fig1.a) and causing lateral compression on the left optic nerve
(arrow). Furthermore, there was a small enhancing nodule at the right orbital apex
(Fig 1.a, arrow head)
Figure 2: A blue-green soft nodule was present on the left cheek
Figure 3: A homogeneous lesion at the infraorbital area of the left cheek was just lateral
to the left nasal ala (arrow)
The MRI scans revealed an ill-defined intraconal mass at the medial portion of the
left orbit causing a lateral pressure effect on the left optic nerve. The mass had
an iso-to-low signal intensity (SI) on T1W, a low SI on T2W, and peripheral patchy
enhancement. The mass involved part of the left superior oblique and left medial rectus
muscles. However, part of the central portion showed a particularly low SI on T2W
without enhancement, which was suspicious of a hemorrhagic component. Moreover, there
was another small, lobulated, intraconal nodule at the right orbital apex that had
a low SI on T1W and a high SI on T2W with homogeneous enhancement. It was located
just lateral to the right optic nerve without intraocular muscle involvement [[Figure 4]].
Figure 4: The magnetic resonance imaging scan revealed that an ill-defined, intraconal mass
at the medial portion of the left orbit (arrow) was causing a lateral pressure effect
on the optic nerve. The mass showed iso-to-low signal intensity on T1W, low signal
intensity on T2W, and peripheral patchy enhancement. It involved part of the left
superior oblique and left medial rectus muscles. However, some central portions displayed
a very low signal intensity on T2W without enhancement, suspicious of a hemorrhagic
component. There was another lobulated, intraconal nodule at the right orbital apex
with homogeneous enhancement (arrow head)
A neurosurgeon was consulted for tissue diagnosis and management of the lesion in
the left orbit. The patient underwent left craniotomy and orbitotomy with the aid
of CT navigation. The finding was a pink, ill-defined, soft, sticky, and easily bleeding
mass at the medial region of the left orbital apex. There were some old blood clots
and a few large blood vessels supplying the mass. The mass adhered to the left medial
rectus muscle, the left superior oblique muscle, and the optic nerve. Tumor removal
was performed. The pathology showed collapsed, thin-walled, vascular channels associated
with a dilated area containing organized thrombus, all of which were compatible with
a hemangioma with an intralesional hemorrhage [[Figure 5]]. The patient was diagnosed as having a CVM with an intralesional hemorrhage at
the left orbital apex. Two days after the surgery, her vision improved from counting
fingers to 20/500 in the left eye. The best-corrected visual acuity of the left eye
20/50 was achieved 1 month postoperatively, and there was no pain nor any limitation
of the patient's eye movement. She attended all follow-up sessions. Two years after
the procedure, her visual acuity was 20/25 in both the eyes. An MRI scan at that time
revealed no change in the CVM in the right eye and no residual tumor in the left eye.
Figure 5: (a) Hematoxylin and eosin staining revealed collapsed, thin-walled, vascular channels
(*) associated with organized thrombus. (b) CD31 staining highlighted the endothelial
cells of the collapsed lumen (arrow head). (c) Smooth muscle actin (SMA) staining
highlighted the smooth muscle cells in the vascular wall
Discussion
We presented a patient with an acute visual loss and pain around the left eye. The
clinical features and orbital imaging of this patient suggested an idiopathic orbital
inflammation. However, we noticed identical that painless lesions were present at
both the right orbit and the left cheek. This observation led us to consider that
the lesions might instead be part of a multiple CVM. After reviewing the patient's
CT scans, we confirmed diagnosis with an MRI scan and a pathology investigation.
Multiple CVMs and bilateral orbital CVMs are rare. This patient had a bilateral orbital
CVM and another CVM on the left cheek. In this case, the lesion was at the orbital
apex, which is a rare location for a CVM. The acute onset of the symptoms in this
patient related to an intralesional hemorrhage in the CVM. The expansion of the intralesional
hemorrhage in the CVM compressed the optic nerve in the very restricted space of the
orbital apex, causing an acute visual loss and orbital pain.
An acute intralesional hemorrhage of an orbital CVM is rare,[[3]] with only a few cases having been reported.[[4]],[[5]],[[6]],[[7]] Interestingly, most of the acute lesions were in the left eye.[[4]],[[5]],[[6]],[[7]] The mechanism of intralesional hemorrhaging of an orbital CVM remains unclear.
It may be caused by inflammation of the small capillaries within the CVM. this would
obstruct the blood circulation and thereby induce a hemorrhage.[[6]] However, a study by Rootman et al. revealed very little inflammation in the histologic
features of intralesional hemorrhages, and they postulated that the cause of the thrombosis
was a vascular stasis eddy formation that induced hypercellularity and stromal changes.[[2]] As the pathology investigation of our patient did not reveal the presence of inflammatory
cells, we concluded that the cause of the thrombosis in our case was slow hemodynamics
in the CVM.
The asymptomatic orbital CVM in the right orbit of this patient did not need surgical
treatment. The CVM may have been related to the blue rubber bleb nevus syndrome.[[8]] Our patient was investigated for other CVMs in the body; fortunately, none were
found.
An orbital CVM can present with an acute and painful visual loss that mimics another
orbital disease, idiopathic orbital inflammation. A careful history and examination,
including a thorough review of orbital imaging, should result in a correct diagnosis
and proper management.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms.
In the form the patient(s) has/have given his/her/their consent for his/her/their
images and other clinical information to be reported in the journal. The patients
understand that their names and initials will not be published and due efforts will
be made to conceal their identity, but anonymity cannot bechrological order guaranteed.
