CervicalThorium Dioxide Granuloma ('Thorotrastoma')

Binh T. Nguyen, David M. Yousem, Richard E. Hayden, and Kathleen T. Montone

Summary: An elderly woman had an expanding cervical mass graines abated in early adulthood. During a work-up for that entrapped and compressed the adjacent cranial nerves, cerebrovascular disease in the 1970s, the patient was blood vessels, and muscles. The mass was dense on radio- noted to have a left neck mass in the same location as the graphs, extendedfrom the skull base to low neck in the prever- current lesion. The patient had surgical exploration of her tebral and parapharyngealtissues, and showed mixed intensity left neck. Although the records from this admission are on MR. A previous direct carotid arteriogram with diox- incomplete, the carotid artery and vagus nerve may have ide as the suggested the histologically proved been injured or resectedat that time. The mass could not diagnosis of a cervical granuloma ("thorotras- be completely excisedbecause of its invasiveness.Patho- toma"). logically, the mass was characterizedas "granulomatous." This massgrew through the 1970sand 1980sand increas- Index terms: Neck, magnetic resonance; Granuloma; Contrast ing neck discomfort, difficulty swallowing, and globus media, complications symptoms developed. Imaging evaluation of this patient included a barium Thorium dioxide (Thorotrast) was introduced swallow,which demonstrateda radiopaqueleft neck mass as a radiologiccontrast agent in 1928 by Radt (Fig 1A), and compressionof the left and posterior aspect (1). An estimated 10 000 to 100 000 patients of the pharynx, vallecula,and piriform sinuses.There was were injected with thorium dioxide worldwide, discoordinatedswallowing. A computed tomography (CT) with approximately4000 to 5000 patients ex- scan showed a peripherally calcified mass in the prever- posedin the UnitedStates (2). Almost all of the tebral and parapharyngeal tissues with evidence of left injected thorium dioxide is retained within the tongue atrophy and vocal cord paralysis (Fig 1B). On body; about 60%is depositedin the , 19%in magnetic resonance(MR), the mass showedmixed inten- sity on pulse sequences, the , and 27% in the reticuloendothelial all thought to representhemor- rhage (Fig 1C-E). A low-intensity peripheral wall system of (3). corre- the marrow The radioactiv- spondedto calcificationseen on CT. An MR angiogram did ity of thorium dioxide and its retention in the not show the left common, internal, or external carotid liver and bone marrow account for the high rate arteries(Fig 1F). of hepatic neoplasmsand blood dyscrasiasas- Becauseof continued growth and discomfort of the left sociatedwith this agent, use of which was dis- neck mass, resectionof the lesion was performed. During continuedin the earlv 1950s. surgery, the mass was noted to be calcified and fibrotic peripherally with a necrotic center. The carotid vessels Case Report could not be identifiedwithin the mass. Pathologicexam- ination revealed granulomatous inflammation associated A 64-year-old white woman presented with difficulty with extensive dense fibrosis, calcification, and the pres- breathing and an enlarging left neck mass. On examina- ence of granular brown pigmented foreign material con- tion, she had inspiratory stridor worseningwith phonation, sistent with thorium dioxide deposits (Fig 1G). Thorium left-sideddeviation of the larynx, left vocal cord paralysis, dioxide was discoveredto be the contrast agent used for a left Horner syndrome, and a large, fixed left neck mass the arteriogramsin 1943. extending from the mastoid tip to the lower neck. The patient's medical history was significant for long- standing hypertensionand migraine headachesas a child. Discussion As part of the evaluation for migraines, the patient had bilateral direct carotid artery puncture arteriograms in Local granulomaformation at the site of in- 1943. No intracranialaneurvsms were seen.and the mi- jection usuallyoccurs 15 or more yearsafter

ReceivedSeptember 12, 1994: acceptedafter revisionNovember 30. From the Departments of Radiology (B.T.N., D.M.Y.), Head and Neck Surgery (R.E.H.), and Pathology (K.T.M.), Hospital of the University of Pennsylvania,Philadelphia. Addressreprint requests to David M. Yousem,MD, Hospitalof the Universityof Pennsylvania,Departrrient of Radiology,3400 SpruceSt, philadelphia, PA 19104.

AJNR l6:1729-1732,Sep 1995 0195-6108/95/1608-1729@ AmericanSociety of Neuroradiology 1729 I73O NCUYEN AJNR: 16, September 1995

Fig 1. A, On the lateral barium swal- low view one seesthe posterior pharyn- geal wall displacedanteriorly by a calci- fied mass. Note also that the patient has aspirated (arows) secondary to disco- ordinated swallowing from her cranial neuropathies. B, The mass (M has a denserim and is located in the prevertebral space on this contrast-enhancedCT. The ipsilat- eral carotid artery and jugular vein can- not be identified. The tongue is atrophied (arrows) from tumor involvement of the extracranialportion of cranial nerve XII. (Figure continues.)

thorium dioxide administration.During intra- Without the history of thorium dioxide expo- vascular thorium dioxide administration, ex- sure, the heterogeneous signal intensity and travasationmay occur, initiatinga local cellular calcified rim on CT and MR with absent flow on reaction against the foreign substance and, in the MR angiogram might suggestthe possibility time, leadingto tissuefibrosis. Thorium dioxide of a thrombosed chronic pseudoaneurysm of carotid angiography had a 3% to 70% rate of the common carotid artery. Pseudoaneurysms extravasationin patients, in at least 50% of have variable MR presentations depending on whom thorium dioxide granulomas ("thorotras- their size and age and the extent of thrombosis tomas") developed(4-6).The cervical mass (12). Concentric, laminated rings of hemor- may entrap cranial nervesIX, X, XI, and XII and rhage in variousstages and a lumen of variable the sympathetic chain, resulting in atrophy of patency (recognizedby a flow void) are typi- respective innervated tissues, pain, cough, callyseen (12). hoarseness,vocal cord paralysis, dysphagia, Other differential diagnostic possibilitiesof a tongue fasciculations,laryngeal edema, dys- mass in this regioninclude calcified tuberculous pnea, and Horner syndrome (7-9). Compres- or fungal infections,myositis ossificans, glomus sion and/or obstruction of cervical blood ves- tumors, and schwannomas.Most patientswith sels may induce cerebrovascularinsufficiency, granulomatousinfections would have systemic vesselthrombosis, vascular erosion,and hem- symptoms or a definite history of previous in- orrhage(9, 10). fection. lt would be rare for such an inflamma- Radiographically,nearly every case of a tho- tory mass to grow without adjacent cellulitic rium dioxide granuloma has shown extensive changes or edema in the fat. The calcification hyperdensity,because of thorium dioxide dep- that was seenin the thorium dioxidegranuloma osition compounded by calcification. Spread would not be unusual in retropharyngealhis- from the skull base to the mediastinum is not toplasmosisor tuberculosis.Myositis ossificans uncommon, presumably becauseof the effect would be unusual in the retropharynx where of gravity or the lymphatic drainage pathways muscle is scarce.Glomus tumors (paragangli- of thorium dioxide-engulfingmacrophages (5, omas) usually are isodenseon noncontrasteT, 7, 17). Necrosiswithin or adjacentto the gran- have flow voids on MR, and dramatically en- uloma, rnanifestedas low density on CT within hance after contrast. Diffuse calcification and the hyperdensemass, hdy occur (11). occlusion of the common carotid artery in a AJNR: 16. September 1995 THORIUM DIOXIDE 7731

Fig 7, continued. C, The prevertebral location of the mass is well demonstratedon this T1- weightedMR image. Note the displace- ment of pharyngeal musculature (white arrow) anteriorly.Again, no ca- rotid artery or jugular vein separable from the mass is identified. The lesion has mixed signal intensity.The stemo- cleidomastoid atrophy (black arrows) on the left signifies cranial nerve XI damage. D, The fat-suppressedfast spin-echo T2-weightedMR image also shows heterogeneityto the signal intensityof the mass. Note that the low-intensityrim (arrows) correspondsto the density seen on CT. E, On -enhanced,fat-suppressed MR images, the lesion showsno significant enhancement centrally, although there are focal areas that may enhance (arows). f;, The time-of-flight MR angiogram through the neck ehows a lack of visibility of the common carotid and internal and external carotid arteries. Collateral vessels may be present superiorly from the vertebrobasilarsystem. G In this pathologic section through mass, dense fibrous tissue containing histiocytes with foreign granular material (arrous) have histologic appearanceconsistent with thorium dioxide (magnification,x 198). paragangliomawould be uncommon findings. coma could have been dense, but one would Schwannomas arising from nerve sheaths of expect a greater degree of enhancementin a cranial nerves IX, X, and XI have a smooth, sarcoma. Only the chondroosseousneoplasms well-definedround or lobular border,are hypo- would calcify so extensively. denseon CT, and moderatelyenhance. They do In summary, history is worth a thousand not usually calcify or occlude vessels. ages. The remote history of exposure to Another considerationin this case is the pos- agent at cerebralangiography provided the sibility of a soft-tissuesarcoma associatedwith agnosisof a thorium dioxide granuloma. the chronic radiation exposure from the extrav- asatedthorium dioxide. Hassonet al noted that neurofibrosarcomas,fibrosarcomas, angiosar- References comas, osteosarcomas,chondrosarcomas, me- 1. Radt P. A method of roentgen contrast visualization of the spleen sotheliomas,and malignant fibrous histiocyto- and liver. KIin Wochenschr 1929;8:2728-2129 mas have been associatedwith thorium dioxide 2. Falk H, Telles NC, lshak KG, et al. Epidemiology of Thorotrast ( 13). The growth of the mass with time and the induced hepatic angiosarcoma in the U.S. Enuiron Res 1979;18: increasingsymptoms might havesuggested the 65-73 possibilityof a sarcoma.A soft-tissueosteosar- 1732 NGUYEN AJNR: 16, September1995

3. Ishikawa Y, Kato Y, Hatekeyama S. Late effects of a-particles on 9. Lung RJ, Harding RL, Herceg SJ, Schantz JC, Miller SH. Long- Thorotrast patients in Japan. ln: Taylor DM, Mays CW, Qerber GB, term survival with Thorotrast cervical granuloma. J Surg Onc et al, eds. BIR Report 21: Risks from Radium and Thorotrast. 7978;70:777-177 London: BIR, 1989:129-131 10.Polacarz SV, Laing RW, Loomes R. Thorotrast granuloma: an 4. Backer OC, Faber M, Rasmussen H. Local sequelae to carotid unexpected diagnosis. Clin Pathol 1992;45:259 -26 7 angiography with colloid thorium dioxide. Acta Chir Scand 1958t Horta JS. Effects of colloidal thorium dioxide extravasates in the 775:477-421 subcutaneous tissues of the cervical region in man. Ann NY Acad 5. Boyd JT, Langlands AO, Maccabe JJ. Long term hazards of Sci 1967;745:776-785 Thorotrast. Br Med J 1968:2:517-521 tz- Atlas SW, Grossman RI, Coldberg HI, et al. Partially thrombosed 6. Blomberg R, Larsson LE, Lindell B, Lindgren E. Late effects of giant intracranial aneurysms: correlation of MR and pathologic Thorotrast in cerebral angiography. Ann NY Acad Sci 1967;145: findings. Radiologg 7987 ;7 62:7 7 1,-7 74 853-858 13.Hasson J, Hartman KS, Milikow E, Mittelman JA. Thorotrast- 7. Amory HI, Bunch RF. Perivascular injection of Thorotrast and its induced skeletal osteosarcoma of the cervical region. Cancer sequelae. Radiologg I 948;51 :831-839 1,975;36:7827-7833 8. Gondos B. Late clinical and roentgen obseryations following Tho- rotrast administration. Clin Radiol 1973:24:795-2O3