solitary fibrous tumor of the pleura ( sftp ) is a rare mesenchymal tumor of fibroblastic origin . sftp can be highly vascular and involves major systemic arteries , such as the subclavian . the treatment of sftp is surgical resection ; however , no standardized approach to the pre - operative evaluation of sftp has been described . herein , we report the case of a large sftp that was evaluated pre - operatively using endobronchial ultrasound ( ebus ) to assess tumor vascularization and thoracoscopy to obtain tissue samples for diagnosis . given the exceptional vascularization noted during this pre - operative assessment , interventional radiology - guided embolization of a branch of the phrenic artery were waived , as this is a retrospective case report with no identifying patient information presented . a 65-year - old healthy male with no prior past medical history presented to his primary care provider with complaints of worsening shortness of breath and cough for several months . his physical examination was significant for dullness to percussion over the right hemithorax and absent airflow on auscultation of the same area . chest x - ray revealed a dense opacification of the right lung base with marked hypoinflation of the right lung . a subsequent ct scan of the chest confirmed the presence of a large mass filling the lower right hemithorax , compressing the right lung , and causing mild mediastinal shift ( fig . the resultant histopathology revealed fibrous tissue , but was inadequate to make a definitive diagnosis . computed tomography scan and chest radiograph showing a large mass occupying the right lower hemithorax . the case was discussed with a multidisciplinary team , including members of the interventional pulmonary and thoracic surgery services . because of the tumor 's very large size and concern about proceeding with en bloc resection without definitive pathology or characterization of its blood supply , the decision was made to do further testing . medical thoracoscopy , bronchoscopy , and ebus were performed in a single diagnostic session by the interventional pulmonologist . flexible bronchoscopy was performed to exclude endobronchial involvement of the lesion . because the vascular supply of sftp often originates from the subclavian or central arteries , we used curvilinear ebus to evaluate the tumor vasculature by starting from the upper trachea . scanning , at the distal end of the bronchus intermedius , revealed a large vessel supplying the mass originating from the direction of the diaphragm . based on the anatomical location , we felt that this likely corresponded to a branch of the phrenic artery ( fig . medical thoracoscopy was then performed with a semi - rigid thoracoscope in order to obtain biopsies and inspect the surface of the tumor ( fig . single - lung ventilation was performed by placing a balloon blocker to the right main stem bronchus . then , careful blunt dissection at the 5th intercostal space ( midline axillary ) was performed . the bronchial blocker was then removed and the right lung was allowed to re - expand . the tumor 's lateral surface was examined and biopsies were obtained with flexible forceps . to obtain immediate hemostasis in a possible event of bleeding during thoracoscopic biopsy , argon plasma coagulator and a thoracic surgeon were present in thoracoscopy room . a total of 6 biopsies ranging in size from 0.3 to 1.0  cm were obtained . thoracoscopy revealed a large tumor with both vascular ( upper left ) and encapsulated ( lower left ) components . ebus ( right ) showed no endobronchial invasion but evidence of a large vessel feeding the tumor . because of both the observed vascularity of the tumor and its large size , the patient was referred for ir - guided angiography and embolization of the phrenic artery ( fig . the following day , a right thoracotomy was performed and the lesion was removed en bloc . the excised tumor measured 25 cm in diameter and weighed 2606 g , one of the largest reported in the literature ( fig . , a chest x - ray showed significant re - expansion of the right lung ( fig . the patient 's hospital course was complicated by brief new - onset atrial fibrillation with rapid ventricular response and development of a large pleural effusion . he remained afebrile and his incisions were without signs or symptoms of infection throughout his stay . the chest tubes were removed on post - operative day 8 and the patient was discharged home on post - operative day 9 . at the time of discharge , he reported marked improvement of shortness of breath and cough . angiography identified the phrenic artery as the main blood supply of the tumor ( left ) . chest radiograph on post - operative day 1 showed adequate lung re - expansion ( right ) . the excised solitary fibrous tumor of the pleural measured 25  cm in diameter and weighed 2606  g. primary tumors of the pleura are classified into two major categories : diffuse and solitary . solitary tumors are typically fibrous and not asbestos related , whereas diffuse pleural neoplasms are typically asbestos related . sftp was first described by wagner in 1870 , and defined pathologically by klemperer and rabin in 1931 . sftp occurs equally in men and women , affecting most patients in the 6th and 7th decades of life . approximately 80% of sftp are benign , and treatment for both benign and malignant tumors consists of surgical resection . whereas surgical resection is the standard treatment for sftp , the pre - operative evaluation of such tumors varies . as with our patient , percutaneous transthoracic needle biopsy of the mass often fails to yield enough tissue for diagnosis . we believe that medical thoracoscopy may provide an alternative means of obtaining adequate tissue samples . it has also been suggested that pre - operative bronchoscopy is of no utility beyond ruling out endobronchial involvement of the tumor . however , prior case reports note that sftp can be highly vascular and involve major systemic arteries , such as the subclavian , predisposing to a high risk of intra - operative complications . this has led some surgeons to recommend pre - operative angiography and potential embolization of massive sftp to reduce the risk of intra - operative bleeding and improve overall outcomes . we believe that the present ebus technology provides limited , but important information in evaluating the vasculature of large sftps . endoscopic ultrasound enodoscopy ( eus ) , on the contrary , has been used in other settings to control bleeding and embolize vessels . as higher depth ebus becomes available , this technology may mitigate the need for contrast exposure via angiogram , particularly in high - risk patients such as those with renal failure or contrast allergies . although limited to a single case , the present report is the first , up to our knowledge , to suggest that future advances in ebus technology may provide an alternative option to angiography , both diagnostically and therapeutically in the pre - operative evaluation of sftp .
abstractsolitary fibrous tumor of the pleura ( sftp ) is a rare tumor of fibroblastic origin 
 . it can be quite vascular , and its surgical management carries the risk of a major intra - operative bleed . 
 the pre - operative use of endobronchial ultrasound ( ebus ) to visualize the vascular supply of the tumor has not been reported.we report a case of a patient presenting with progressive shortness of breath and cough who was found to have a very large pleural - based tumor . 
 we describe the use of medical thoracoscopy and ebus to establish the diagnosis of sftp and to characterize the blood supply of the tumor.in the future , ebus may provide an alternative to conventional angiography for both mapping and embolizing tumor blood supply .