a 19-year - old man with 6-year history of chest pain and 6 months of progressive paraplegia with associated hypertension was admitted for further work up of a known mass in the thoracic spine . mri findings evidenced a thoracic tumor extending from t4 to t9 with an associated t6 vertebral fracture and a l3 metastatic lesion ( fig . iodine-123 metaiodobenzylguanidine scintigraphy ( i-123 mibg ) showed intense uptake within the same areas ( fig . 1c ) . a spinal digital subtraction angiography ( dsa ) showed a prominent tumor blush , with arterial feeders arising from the right t5 through t10 intercostal arteries . an ultrasound guided biopsy confirmed it to be a paraganglioma ( fig . 3a and 3b ) . there was no history of any associated familial syndromes and genetic testing did not display any known abnormality . a functional , malignant thoracic paraganglioma was diagnosed and sequential alpha and beta blocker was started in preparation for a staged combined treatment . the patient underwent a successful presurgical tumor embolization of arterial feeders coming from the right t7 , t8 and t9 intercostal arteries in three consecutive days , using liquid embolic material ( onyx , covidien inc . , irvine , ca ) through a 410 mm scepter - c balloon catheter ( microvention inc . , tustin , ca ) . the presurgical augmented embolization archived more than 90% reduction of the tumor blush ( fig . 2b ) . the surgical treatment consisted of two stages . in the first surgery the patient had a partial t5 , complete t6 , partial t7 laminectomy , and pedicle screw fixation of t4 , t5 , t7 , and t8 with posterolateral fusion . the surgery lasted 7.5 hours with an estimated blood loss of 700 ml . a second surgery five days later consisted of a right posterolateral thoracotomy and total gross resection of the thoracic paraganglioma ( fig . it lasted 7 hours with an estimated blood loss of 4500 ml requiring 4 units of packed blood cells , 10 units of platelets , 4 units of fresh frozen plasma and 500 ml of albumin . of note , prior to the admission the patient had an attempted tumor resection through a right thoracotomy in another hospital where the procedure was abandoned due to a significant blood loss . microscopic examination of the resected specimen showed coagulative necrosis of the tumor with the embolic material completely occluding an artery and some viable tumor cells after the embolization ( fig . the response was less intense after every intervention and was managed pharmacologically without complications ( table 1 ) . this is a case of a large thoracic , functional malignant paraganglioma treated with trans - arterial onyx embolization of its three major vascular feeders and two subsequent surgeries . there is no consensus in the definition of malignant paraganglioma and the only consistent criterion among the proposed indicators is the presence of metastatic disease . more importantly , no histological criteria have shown to be a reliable marker of aggression . the hypervascular nature of these tumors associated with other characteristics , like location and catecholamine secretion make their resection challenging . for this reason presurgical embolization can be a valuable and safe tool in the management of these tumors as it has been shown to reduce the risk of catecholamines release during surgical manipulation of the tumor , decrease the intraoperative blood loss , and decrease the number of transfusions , therefore reducing the operative time , complications and local recurrence [ 4 , 5 , 8 ] . in our case , each presurgical embolization resulted in a reduced catecholamine secretion as evidenced by the subsequent reduction in the magnitude of the hypertensive response . although there was a significant blood loss during the surgical excision of the tumor in our case , we believe that it would have been more prominent without the embolization . as discussed by other authors , the estimated blood loss and operative time are influenced by other factors other than the embolization , like invasiveness of the procedure and surgical approach . to date , only five cases of presurgical embolization of thoracic paragangliomas have been reported [ 3 , 4 , 5 , 6 , 7 ] . only one of them was functional , and differs from our case in that it was a metastatic lesion involving one vertebral level . the embolic materials reported included gelfoam and the most commonly used polyvinyl alcohol , all with positive results . ghobrial et al showed the feasibility of trans - arterial embolization with onyx in the management of spinal tumors although most of their cases represented by metastatic renal cell carcinomas . when compared with other agents , onyx demonstrated higher rates of angiographic obliteration and intraoperative bleeding reduction , although the difference did not reach statistical significance . advantages of onyx are related to its properties that permit more control and longer injections and deeper penetration through the tumor vascularity . it also gives excellent surgical handling properties that help with the tumor resection [ 8 , 10 ] . in summary , the combination of onyx with the scepter c balloon seems to be a good option when aggressive embolization of functional thoracic paraganglioma is intended .
paragangliomas are rare tumors of the endocrine system . 
 they are highly vascular and in some cases hormonally active , making their management challenging . 
 although there is strong evidence of the safety and effectiveness of preoperative embolization in the management of spinal tumors , only five cases have been reported in the setting of thoracic paragangliomas . 
 we present the case of a 19-year - old man with a large , primary , functional , malignant paraganglioma of the thoracic spine causing a vertebral fracture and spinal cord compression . to our knowledge 
 this is the first report of preoperative trans - arterial balloon augmented onyx embolization of a thoracic paraganglioma .