we present spontaneous retrobulbar hemorrhage in a 52-year - old woman with history of breast cancer and tamoxifen intake which was first thought to be an orbital metastasis .
a 52-year - old woman with history of breast cancer and tamoxifen intake was referred due to severe proptosis and visual loss .
after exploration , multiple fragments of dark brown mass in the retrobulbar area were excised .
spontaneous retrobulbar hemorrhage is a rare condition that may have unknown etiologies , and its symptoms may mimic orbital metastasis . since both breast cancer and tamoxifen intake can cause coagulation disorders , they might be possible causes for retrobulbar hemorrhage in this case .
retrobulbar hemorrhage may occur spontaneously or as a subsequent of a distinct etiology . some etiologies known until now include orbital vascular anomalies , subsequent trauma , surgery around the orbit , and systemic disease such as coagulopathy , toxic conditions , and uncontrolled hypertension .
herein , we present a case of spontaneous retrobulbar hemorrhage that developed symptoms mimicking orbital mass and did not have known etiology except history of breast cancer and tamoxifen intake .
a 52-year - old woman with history of breast cancer was referred to oculoplastic service , farabi eye hospital , tehran , iran for evaluating proptosis .
a compressive orbital mass was detected in her mri and was taken to the neurologic department .
she had complained of acute ocular pain and progressive visual loss in her left eye from 2 weeks earlier . she had been using tamoxifen since 5 years earlier after mastectomy due to her right breast cancer .
she had no history of other systemic disease or trauma . on examination , left eye visual acuity was finger count at 1  m , and she had a left afferent pupillary defect .
there was a severe inferolateral proptosis ( 28  mm in hertel exophthalmometry ) , secondary ptosis , and limitation of ocular motility in almost all directions , especially in elevation and adduction ( fig .  1 )
routine lab tests and hematologic tests including bleeding time , clotting time , and platelet count were within normal limits without evidence of bleeding tendency .
orbital ct scan showed an elliptical well - defined mass within the left intraconal space .
it was a high - density and homogenous consistency mass that compressed and displaced the optic nerve to the supranasal side ( fig .  2 ) .
orbital t1 weighted mri demonstrated an intraconal mass extending to the orbital apex that had a hypointense layer around the hyperintense mass without enhancement ( fig . 
weighted mr scan , the intraconal mass was isointense but the superior part of the mass was hyperintense , and the other part that was near the orbital apex was hypointense ( fig . 
the patient underwent supralateral lid crease orbitotomy . while opening the mass , at first a yellowish liquid was depleted , and then gelatinous , semiclotted blood was removed .
finally , a solid mass that was similar to a hard blood clot remained ( fig .  4 ) .
visual acuity dramatically improved to 20/30 one week after operation , and other clinical symptoms and signs improved completely .
spontaneous retrobulbar hemorrhage without known etiology is rare . in many case reports differentiation between retrobulbar hematoma and tumor metastasis according to clinical symptoms has been impossible .
metastatic breast cancer is the leading cause of orbital metastasis and is responsible for 4853% of orbital metastatic tumors .
imaging such as ct scan and mri plays an important role to differentiate between metastatic breast cancer and retrobulbar hematoma .
there are multiple characteristic features to diagnose metastatic breast cancer in mri and ct scan , including diffuse intraconal lesions , intra - muscle masses , and diffuse enhancement of retro - bulbar fat with abnormal heterogenous hypointensity and fibrotic infiltration and bone destruction contagious to the mass .
but in our case , axial t1 weighted mri obtained 15 days after beginning of symptoms demonstrated a halo of low signal mass surrounding a high signal mass .
these findings express a hematoma that has started to undergo physical changes and biochemical hemoglobin lysis . on the other hand , a deeper part of the hematoma had a solid part that was hypointense both at t1 and t2 and presented like a foreign body at mri ( hypointense at t1 and t2 ) . even though it was predictable that the mass could be a hematoma considering the acute onset and multilayer nature of the mass in mri , we did not offer a needle aspiration before surgery for two reasons : firstly , the deeper part of the mass seemed to be dense and solid according to mri , so we could not aspirate it easily . secondly , the most important differential diagnosis in this patient was orbital metastasis , and needle aspiration did not seem to be a good plan for its management .
several cases of retrobulbar hemorrhage without definite etiology similar to our case has been reported.1 , 2 , 4 matsuura et  al . reported a patient with orbital discomfort and exophthalmos without concomitant trauma , which firstly has been mistaken to be an orbital tumor .
orbital ct scan revealed a round mass without enhancement , after surgical removal and diagnosis was blood cyst .
reported a 75-year - old man who presented with sudden onset visual loss , orbital pain , and exophthalmos .
patients with history of breast cancer are at higher risk for coagulation disorders compared with the healthy population .
furthermore , hypercoagulability state could be induced by different medical interventions such as hormonal agents in this group of patients .
numerous clinical studies revealed that tamoxifen could increase the risk of venous and arterial thrombosis rather than increasing bleeding tendency.6 , 8 the presented case did not have any known disease that can cause retrobulbar hemorrhage except for history of breast cancer and tamoxifen intake .
as there was not any evidence for orbital metastasis or disease recurrence in this patient , we can not easily attribute this orbital hemorrhage to them .
the second most important suspicious cause for hemorrhage in this patient could be tamoxifen , if we could consider it as a cause for chronic mild disseminated intravascular coagulopathy . as we know
, this is the first case report of spontaneous orbital hemorrhage in a patient with history of breast cancer and tamoxifen intake , so it could be considered as a basis for further research .
 purposewe present spontaneous retrobulbar hemorrhage in a 52-year - old woman with history of breast cancer and tamoxifen intake which was first thought to be an orbital metastasis.case reporta 52-year - old woman with history of breast cancer and tamoxifen intake was referred due to severe proptosis and visual loss . 
 orbital imaging showed an intra - conal mass . 
 after exploration , multiple fragments of dark brown mass in the retrobulbar area were excised . 
 microscopic diagnosis was blood clot . 
 all of clinical signs and symptoms were improved 1 week after operation.conclusionspontaneous retrobulbar hemorrhage is a rare condition that may have unknown etiologies , and its symptoms may mimic orbital metastasis . since both breast cancer and tamoxifen intake can cause coagulation disorders , they might be possible causes for retrobulbar hemorrhage in this case . 
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Case report
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