Pulmonary artery obstruction and cor pulmonale due to chronic fibrous mediastinitis

Pulmonary Artery Obstruction and Cor Pulmonale Due to Chronic Fibrous Mediastinitis* MAJ . WILLIAM P . NELSON, MC, f MAJ . GEORGE D . LUNDBFRG, Met and COL . ROBERT B . DICKERSON, MC§ Fort Sam Houston, Texas

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ing substernal discomfort on exercise . Because of the persistence of these symptoms and increasing limitation of activity she was hospitalized at another hospital in January 1959 . Nine days after admission she was referred without medication to this hospital for evaluation . In the brief interim between hospitalizations the symptoms continued and mild swelling of the ankles developed . At no time had the illness been accompanied by fever, pleuritic chest pain, hemoptvsis or manifestations of joint involvement, There was no background history of unexplained febrile illnesses or signs or symptoms to suggest rheumatic fever . The patient had never been told that she had a heart murmur . During childhood she had been active and healthy with only the usual childhood illnesses . She had had no significant illnesses in adulthood, The review of systems did not disclose any abnormalities except for a weight loss of 15 pounds during the five months prior to adm. .ssion, which had occurred despite a normal appetite and usual diet . Examination on admission revealed a woman in no acute distress who did not appear ill . The following positive and pertinent negative findings were noted . The blood pressure was 130/90 mm . Hg . Peripheral pulses were all of good quality and equal ; the pulse was regular at 72 beats per minute . Venous pressure in the right arm was 160 mm . of saline solution and the circulation time (arm to tongue) was 25 seconds . There was no clubbing or cyanosis . The thyroid was minimally enlarged, without audible bruit over the gland . There was mild prominence of the eyes with no true exophthalmus or thyrotoxic eye signs . The cervical veins were distended at an elevation of 30 degrees with poorly defined venous pulsations . The precordium was hyperactive on palpation ; the maximum palpable impulse was situated 3 cm . to the left of the lower

HRONIC fibrous mediastinitis (sclerosing mediastinitis) is not encountered often,

and when observed is most frequently manifested by the signs and symptoms of superior vena caval obstruction . There are, however, numerous clinical syndromes which may occur, depending on which mediastinal structure (or structures) becomes involved in the fibrosing process . We have observed a patient in whom the scarring process had completely obliterated the left pulmonary artery and seriously obstructed the right pulmonary artery. Although this complication has been documented in the European literature [ 1-3], we have been unable to find a report of a case in the English language literature . CASE REPORT

A thirty-one year old Negro woman, (E . H.) was admitted to Brooke General Hospital for the first time in March 1959 for cardiac evaluation . The patient had been in good health until five years prior to admission when she was seen at another hospital because of aching anterior chest discomfort and breathlessness on exertion . Chest roentgenograms were obtained and the patient was told they showed no abnormality . She was reassured and given no specific medication. Subsequently, her condition improved and she remained generally asymptomatic until July 1958 when she noted the onset of exertional dyspnea and nonproductive cough . These symptoms progressed and in the ensuing several months she became more easily fatigued with shortness of breath in the recumbent position, and had more frequent episodes of ach-

* From the Departments of Medicine and Pathology, Brooke General Hospital, Fort Sam Houston, Texas. Manuscript received February 3, 1964. f Present address : William Beaumont General Hospital, El Paso, Texas . $ Present address : William Beaumont General Hospital, El Paso, Texas . Present address : Walter Reed General Hospital, Washington, D . C . VOL .

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Fig . 1 . Chest roentgenogram showing cardiomegaly and a "water bottle" contour, suggesting pericardial effusion . sternal border. A faint thrill was palpable in the second left interspace parasternally . The left border of cardiac dullness was percussed 2 cm. lateral to the mid-clavicular line and the heart was regarded as enlarged . On auscultation the second heart sound in the second left interspace was widely split, the pulmonic component being greater than the aortic . The splitting varied little with quiet respiration, but diminished markedly during the Valsalva maneuver . The first heart sound at the lower left sternal border and "apex" was normal. There was a grade 3, medium-pitched, moderately harsh systolic murmur audible at the base of the heart (the upper and posterior portions of the right side of the chest) with nonselective radiation to both carotid arteries. The murmur was best heard at the mid-point of the right sternal border . Its peak occurred apparently at midsystole, but continued through the second heart sound, rapidly waned and disappeared by middiastole . The murmur increased during inspiration and disappeared during the Valsalva maneuver. There was no palpable abdominal organomegaly. The remainder of the physical examination was within normal limits . The hemoglobin was 11 gm . per cent, hematocrit 35 volumes per cent and the total white blood cell and differential counts were normal. The results of a serologic test for syphilis were negative. Urinalysis did not reveal any abnormalities . The hemoglobin was type A by paper electrophoresis . The proteinbound iodine was 4 .4 pg . per cent . Oxygen saturation by ear oximetry was 95 per cent (the control quantity is 98 per cent) . A roentgenogram of the chest (Fig. 1) showed over-all enlargement of the cardiac silhouette with a "water bottle" contour sug-

gesting pericardial effusion . Pulmonary vascularity was regarded as within normal limits. Cardiac fluoroscopy suggested combined right and left ventricular enlargement . The amplitude of cardiac pulsations was regarded as normal . There was considerable fullness in the pulmonary artery segment, with elevation of the main stem of the left bronchus . Left atrial enlargement was suggested . An electrocardiogram was obtained which showed a poorly defined frontal plane QRS axis, with a precordial pattern consistent with right ventricular hypertrophy. Digitalis was administered, salt intake was restricted and the patient was given mercurial diuretics which resulted in a weight loss of 5 pounds. Cardiac catheterization was attempted but was technically unsatisfactory because of venospasm. A right ventricular pressure record showed a systolic pressure of 58 mm . Hg . No valid oxygen saturations were obtained . It was not possible to enter the pulmonary artery . Subsequently the patient was discharged on medication . She was readmitted in August 1959 . During the interval between hospitalizations she had noted mild improvement in exercise tolerance, which was still quite limited because of exertional dyspnea . In general the findings on physical examination were unchanged . Venous pressure in the right arm was 200 mm . of saline solution and circulation time (arm to tongue) was 28 seconds . Again she was given mercurial diuretics and there was a weight loss of 7 pounds and a slight decrease in measured venous pressure . On August 11, 1959, cardiac catheterization was attempted utilizing basal sedation and local anesthesia, but again it was impossible to manipulate a standard catheter because of venospasm . A large bore catheter was inserted and angiocardiography was accomplished by injection into the left innominate vein . There was no untoward reaction to the injection of contrast material and the patient returned to the ward in good condition . The angiograms obtained (Fig . 2) were poor technically but interesting in several respects . The distal portion of the superior vena cava appeared to taper slightly, suggesting extrinsic compression . With opacification of the right atrium a peripheral shell of nonopacified silhouette consistent with pericardial effusion was delineated . The main pulmonary artery was markedly enlarged . No contrast material could be seen in the left pulmonary artery in either frontal or lateral projection . The right pulmonary artery appeared to narrow abruptly and there was minimal opacification of the peripheral right pulmonary artery branches in serial roentgenograms . Four hours after completion of the procedure, the patient suddenly cried out and collapsed . The ward intern was at an adjacent bed when collapse occurred and on finding no palpable pulse performed a penknife thoracotomy . The pericardium was found

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Photograph of the gross pathologic specimen demonstrating partial obstruction of the right pulmonary artery branches and pulmonary veins by the fibrous mediastinal mass. FIG . 3 .

Fig. 2 . Frames from angiocardiogram . A, tapering of the distal superior versa cava, suggesting extrinsic compression . Lateral to the right atrium, a nonopacified rim (arrow) of pericardial fluid may be observed, B, a later frame, shows marked enlargement of the main pulmonary artery . No branches of the left pulmonary artery are evident . The right pulmonary artery narrows abruptly and there is minimal opacification of peripheral branches . to he distended tensely with fluid and on incision an estimated 400 cc . of serous fluid gushed forth . The heart was found to be at a standstill . Effective cardiac massage and oxygenation were instituted and adequate cardiac contraction resumed . The patient, however, failed to respond to treatment and showed signs of severe brain damage, which persisted until she died on August 15, 1959 . VOL .

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Photograph of the gross pathologic specimen demonstrating total obliteration of the left pulmonary artery (arrow) immediately distal to the bifurcation of the main pulmonary artery . FIG . 4.

A specimen of pericardial fluid was submitted for bacteriologic studies . No organisms were observed on direct smear (gram and acid-fast stains) . Cultures for bacteria and acid-fast bacilli were negative . At autopsy, the body was observed to be normally developed and nourished . The major pathologic changes were within the thorax . The middle and superior mediastinum were involved diffusely by a 6 by 3 cm . hard, gray-white mass . (Fig . 3 .) The mass was bounded superiorly by the aortic arch, anteriorly by the pericardium and posteriorly by the trachea and main stem bronchi ; the bilatcral extension was

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5 . Mature broad bands of collagen which comprise the mediastinal mass . Hematoxylin and eosin stain, original magnification X 170 . FIG .

well into the hilum of each lung . The left side of the heart was of average size, but there was marked ventricular hypertrophy (0 .6 cm . in thickness) on the right side . The proximal left pulmonary artery, 1 cm . distal to the bifurcation of the main pulmonary artery, was totally obliterated by apparent extrinsic pressure. (Fig . 4.) Complete endothelialization proximal and distal to the 2 cm . long obstruction was evident grossly. At a point 3 cm . from its origin, the right pulmonary artery was the site of 50 per cent luminal narrowing. The pulmonary veins were small bilaterally and obstructed partially by compression, but the superior and inferior venae cavae were uninvolved grossly. There was no appreciable impingement on the lumen of the tracheobronchial tree . Pulmonary hilar lymph nodes were enlarged bi-

Fro . 6. Longitudinal section of the left pulmonary artery demonstrating fibrous compression (A) and intimal proliferation (B) . Weigert-van Geison stain, original magnification X 5 .

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laterally. These were found to have fibrocaseous and calcitic areas which were surrounded by and blended with the hard mediastinal mass. The microscopic nature of the lesion was similar throughout . It consisted of a disarray of swollen, broad band forms of brightly eosinophilic collagen fibers containing relatively few spindle-shaped nuclei which were small and eccentrically located . (Fig. 5 .) There was minimal fibroblastic activity . Inflammation was sparse generally but a moderate focal interstitial infiltrate of lymphocytes and monocytes and rare plasma cells and eosinophils were present, especially in areas of continuing fibroblastic activity . The fibrous proliferation involved and surrounded all hilar lymph nodes ; the latter contained lymphocytes which were normally developing, as well as much'anthracotic pigment and large masses of calcium, The fibrous proliferation was limited sharply by pleura and pericardium . However, it involved the trachea and bronchi externally by compression and infiltration between cartilage rings and into the submucosal glands . The pulmonary arteries and veins were compressed mainly but infiltrated partially by the process as demonstrated by the Weigert-Van Gieson elastic tissue stain . About 75 per cent of the left pulmonary artery obstruction was produced by fibrous compression ; the remainder was produced by loose, acid mucopolysaccharide-rich, intimal proliferation . (Fig . 6 and 7 .) A few foci of granulomatous inflammation Containing epithelioid cells, Langhan's giant cells and focal cascous necrosis were present within the fibrous mass . Multiple smears and cultures of hilar lymph node material and mediastinal fibrous tissue for fungi and acid-fast bacilli were negative . Multiple sections of mediastinal fibrous tissue, pulmonary hilar lymph

Higher power of Figure 6 (B) showing florid intimal proliferation . Colloidal iron stain, original magnification X 105. FIG . 7 .

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Chronic Fibrous Mediastiniti nodes and lung parenchyma were studied after being stained with Gomori's silver methenamine, periodic acid-Schiff and Kinyoun carbolfuchsin stains . No fungi were observed, but a single acid-fast bacillus resembling Mycobacterium tuberculosis was found . A small inactive subpleural fibrous granuloma was present in the upper lobe of the left lung . No causative organisms were found in this nodule . The upper lobe of the right lung contained a recent hemorrhagic infarction measuring 3 by 5 cm. which was associated with a small pulmonary arterial embolus . The final anatomic diagnoses were (I) sclerosing mediastinitis. probably due to Myco . tuberculosis, with total left pulmonary artery and partial right pulmonary artery and pulmonary vein obstruction ; (2) pulmonary infarction of the upper lobe of the right lung ; (3) right ventricular cardiac hypertrophy and dilatation ; (4) pulmonary granuloma of undetermined etiology in the upper lobe of the left lung ; (5) mild aortic and peripheral arterial atherosclerosis ; and (6) left pulmonary atelectasis, acute left pleuritis, pericardial laceration, acute pericarditis, cerebral edema and neuronal degeneration . (The latter group of findings was due to open cardiac massage and prolonged circulatory arrest .) In retrospect, the puzzling picture presented was exactly what would be expected with this lesion . The peculiar cardiac murmur, because of its respiratory variation, was clearly of pulmonary artery origin . The continuation of a pulmonary systolic murmur into diastole has been clarified as an auscultatory feature of coarctation of the pulmonary artery, either congenital [4] or acquired [51 . In effect, the fibrosing process had resulted in acquired pulmonary artery "coarctation . " This condition results in dilatation of the main pulmonary artery, right ventricular hypertension and ultimately possible right ventricular failure [6] . Right ventricular hypertension and/or main pulmonary artery distention can cause oppressive chest discomfort resembling the symptoms of angina pectoris [71 . Pulmonary venous compression, although mild . certainly resulted in some impediment to flow and is ample explanation for this patient's exertional dyspnea and orthopnea. The cause of the pericardial effusion was not determined . COMMENTS

Chronic fibrous mediastinitis, as the name implies, is an indolent, slowly progressive scarring process . The mode of presentation depends obviously upon which of the thoracic organs becomes involved in the scar tissue, and the severity of illness varies with the extent of the process and the structure (or structures) compromised . The most vulnerable of the thoracic cardiovascular structures is the low pressure caval system and the majority of cases of mediastinal VOL . 38,eeBRUARY

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fibrosis reported [8-14] are concerned with superior vena caval obstruction . The first such case was reported over 100 years ago [15] . There have been several large series of cases of superior vena caval obstruction and mediastinal fibrosis has been incriminated as the cause in from 10 to 23 per cent [16-20] . As Barrett [141 so aptly puts it, "The clinical hallmark of mediastinal fibrosis is the presence of venous hypertension in the catchinent area of the superior vena cava ." The present case, however, is a sharp departure from the norm and, with other reported cases, contradicts the published opinion [211 that "only the great veins are involved ." Structures in the middle and posterior mediastinum are most vulnerable to the scarring process . Cases reported in the literature have indicated significant involvement o- the tracheobronchial tree [22], serious pulmonary venous obstruction [22-26] and symptomatic esophageal compression [27] . There are several reports in which these structures were involved in various combinations [22,281 . One case was reported [29] in which evidence of coronary artery and proximal aortic involvement was presented . We have been unable to find any reports of significant involvement of the ascending aorta or branches of the aortic arch . It is probable that mediastinal fibrosis and the entity of retroperitoneal fibrcsis are related conditions and, although the etiology remains poorly defined, represent similar disease processes [30] . Indeed, at least six cases [/ 1,21,28,29, 31,32] have been reported in which mediastinal fibrosis and retroperitoneal fibrosis coexisted . Retroperitoneal fibrosis (also known as Orround's disease [33], sclerosing retroperitonitis [30], perirenal (Gerota's) fasciitis [34], pcriureteric fibrosis, sclerosing lipogranulonaa [35], lipophage granuloma and adiponecrosis) usually manifests ureteral compression and obstruction . Since it was first described by Ormond in 1948 [36], at least 100 cases have been reported [37] . The most common clinical symptoms of retroperitoneal fibrosis result usually in urologic consultation but, as Ormond has emphasized, the process is not primarily a "urologic disease ." As in mediastinal fibrosis, a variety of structures may be involved in the retroperitoneuun (the inferior vena Cava [38,39] or branches of the abdominal aorta [39,40]), Occasionally, the process departs from the retroperitoneum to involve other abdominal organs [28 .311 .

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The microscopic similarity of mediastinal and retroperitoneal fibrosis lends support to the view that they are merely topographical variants of the same disease . Reports of cases of either mediastinal fibrosis or retroperitoneal fibrosis contain monotonously uniform descriptions of the microscopic pathology, merely an inflammatory reaction in connective tissue without suppuration and varying only in the amount of inflammation, the stage of "maturity" of the fibrous proliferation and the degree of scarring . The histologic appearance has suggested to several investigators [14,22,41] that mediastinal and retroperitoneal fibrosis are related to other "fibrosing" diseases, such as fibrous thyroiditis (Riedel's struma), pseudotumor of the orbit, Dupuytren's contracture of the palmar fascia and Peyronie's disease of the penis . Recently, because of its coexistence with Riedel's struma and fibrous mediastinitis and because of microscopic similarity, sclerosing cholangitis has been proposed as an addition to this list [42] . Previous reports [30,39] have also suggested a histologic resemblance between keloids and the fibrous proliferation of chronic fibrous mediastinitis . The fact that the present patient was a Negro and a young adult lends support to the concept in this case, although the past and family histories revealed no tendency toward cutaneous keloid development . Allen [43] suggested the possibility of visceral keloid formation, but we have been unable to locate any acceptable reports of such a growth . In the present case bilateral subtotal pulmonary artery obstruction was the result of fibrous compression . The final obliteration of the left pulmonary artery, however, was produced by intimalproliferation . (Fig . 6and7 .) Oneexplanation of this phenomenon may be found in the studies of Rodbard [41-47] which suggest that once a critical degree of external compression of a major artery is reached in the absence of collateral circulation, the process becomes selfperpetuating by increasing intimal proliferation . The cause of most cases of mediastinal fibrosis and retroperitoncal fibrosis is unknown despite extensive bacteriologic, serologic and pathologic study . Either tuberculosis or syphilis was incriminated as the cause in the older literature [8,9] Most cases however, did not provide either bacteriologic or histologic support for this theory . We believe that the exuberant fibrous overgrowth in the mediastinum in the present case is due to a tuberculous lymphadenitis, since

one acid-fast bacillus and several granulomatous foci suggesting tubercles were found . In the absence of cultural confirmation, however, we realize this is but speculation . Numerous other agents have been proposed as the cause . In several instances convincing evidence incriminating specific infections has been presented [48] . This lack of agreement regarding etiology emphasizes the probability that there are many initial causes . It seems reasonable that the fibrous reaction observed, whether in the mediastinum, retroperitoneum or elsewhere, is merely fibrous over-response to a variety of stimuli . Such stimuli may be infectious, traumatic, toxic or immunologic . This is not to say, however, that an investigation for the responsible agent should not be conducted so appropriate treatment may be devised . To date, the only consistently helpful therapy has been surgical release of the obstructed organs . X-ray therapy and adrenal steroid administration have been suggested, but the results of these treatments have not been convincing [30] . SUMMARY

A case of extensive mediastinal fibrosis with the unique complication of pulmonary artery obstruction leading to cor pulmonale is presented . REFERENCES 1 . Quoted by Soderberg, G. [2] . 2 . SODERBERG, G . Om striktur av arteria pulmonalis genom skrumpnande mediastinit . Nord. Med ., 28 : 2051, 1945 . 3 . ToURNAIRE, A ., TREPPoz, M., TARTDLIER, M., DEYRIEUx, F . and VAN STRAATEN, G . Cocur pulmonaire chronique par compression arterielle pulmonaire Bans la maladie du hile d'origine ganglionnaire. Arch . mal . corn, 51 : 960. 1958 . 4 . ELDRIDGE, F ., SELZER, A . and HULTGREN, H. Stenosis of a branch of the pulmonary artery : an additional cause of continuous murmur over the chest, Circulation, 15 : 865, 1957 . 5 . LEvri, H . S . and BOOTH, R . W. Lymph node compression of the pulmonary artery causing a continuous murmur . Am. J. Cordial ., 3 : 972, 1960 . 6 . FALKENBACH, K . H ., ZHEUTLIN, N ., Downy, A. H. and O'LAUGHLIN, B . 7 . Pulmonary hypertension due to pulmonary arterial coarctation . Radiology, 73 : 575, 1959 . 7 . LusSADA, A . A. Colloquium on therapy of right heart failure . Dis . Chest, 41 : 260, 1962. 8 . KNOx, L . C . Chronic mediastinitis . Am. J. M. Sc ., 169 : 807, 1925 . 9 . KEEFER, C. S . Acute and chronic mediastinitis. Arch . Int . Med., 62 : 109, 1938 . 10 . ERGANIAN, J . and WADE, L. L Chronic fibrous mediastinitis with obstruction of the superior vena cava. J. Thoracic Surg ., 12 : 275, 1942 . AMERICAN JOURNAL OF MEDICINE

Chronic Fibrous Mediastinitis--Nelson 11 . TUBBS, O . S . Superior vena caval obstruction due to chronic mediastinitis . Thorax, 1 : 247, 1946 . 12 . KUNKEL, W . M ., JR ., CLAGETT, O. T . and MeDONALD, J . R . Mediastinal granulomas . .I. Thoracic Surg ., 27 : 565, 1954 . 13 . SANTY, P., CALY, P ., PAPILLON, J ., GONIN, A., MARION, P . and PINET, F . Syndromes de compression de la veine cave superieuse par mediastinitc libreuse d'originc ganglionnaire t uberculeuse . J . radial . e t electral ., 39 :407, 1958 . 14. BARRETT, N. R, Idiopathic mediastinal fibrosis . Brit, J. Surg ., 46 : 207, 1958 . 15 . BALLET, C . H . Edinburgh M . J., 69 : 269, 1848 . Quoted by Tubbs, O. S. [71] . 16. OsLER, W. On obliteration of the superior vena cava. Bull . Johns Hopkins Hosp ., 14 : 169, 1903 . 17. OCHSNER, A. and DIKON, J . L. Superior vena caval thrombosis : review of literature and report of cases of traumatic and infectious origin . J. Thoracic Sag ., 5 : 641, 1936. 18 . MCINTIRE, F . J . and SYKES, E . M . Obstruction of the superior vena cava : a review of the literature and report of two personal cases . Ann . Int. :Wed., 30 : 925, 194919 . SCHEOHrER, M . M . The superior vena cava syndrome. Am . J. M. Sc ., 227 : 46, 1954. 20 . FAILOR, H . J ., EDWARDS, J . E. and HODGSON, C . H . Etiologic factors in obstruction of the superior vena cava . Proc. Staff !feet. Mayo Clin ., 33 : 671, 1958 . 21 . CAMERON, 1) . C ., ]NO, S . T ., BOYLE, M . and MATHEWS, W . H. Idiopathic mediastinal and retroperitoneal fibrosis . Canad . M . A . .J ., 85 : 227, 1961 . 22 . HACHE, L ., WOOLNER, L . B . and BERNATZ, P . E. Idiopathic fibrous mediastinitis . Dis. Chest, 41 : 9, 1962 . 23. EDWARDS, J. E. and BURCttELL, H . B . Multilobar pulmonary venous obstruction with pulmonary hypertension . Arch . Int. Med ., 87 : 372, 1951 . 24. DAVIS, F . W. and ANDRUS, E . Cowles mitral stenosis in facsimile . New England J. Med., 251 : 297, 1954 . 25 . ANDREWS, E . C ., JR . Five cases of an "described form of pulmonary interstitial fibrosis caused by obstruction of the pulmonary veins . Bull . Johns Hopkins Harp ., 100 : 28, 1957 . 26 . BINDET.GLASS, I . L . and TRUanwaTZ, S . Pulmonary vein obstruction : an uncommon sequel to chronic fibrous mediastinitis . Ann . Int . Med ., 48 : 876, 1958 . 27 . GARAMELT .A, J . J ., STUTZMAN, F. L ., VARCO, R. L. and JENSEN, N . K . Subcarinal mediastinal granulomas causing esophageal obstruction . J. Thoracic Surg ., 30 : 187, 1955 . 28 . INKI.EY, S . R . and ABBOTT, C . R. Unilateral pulmo-

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nary arteriosclerosis . Arch . Int. Med ., 108 : 903, 1961 . 29 . REED, W . G. and SrINELY, R . W . Massive periaortic and periarterial fibrosis . New Englm¢d J . Med ., 261 320, 1959 . 30 . HARK, W, A. and HAZARD, J . B . Sclerosing retroperitonitis and sclerosing mediastinitis . Am . J. Clin . Path ., 32 : 321, 1959 . 31 . PARTINGTON, P . F . Diffuse idiopathic fibrosis, .Ant J. Surg ., 101 : 239, 1961 . 32 . DINEEN, J ., AstH, T. and PEARCE, J . M. Retroperitoneal fibrosis . Radiology, 75 : 380, 1960 . 33 . ORMOND, J . K . Idiopathic retroperitoneal fibrosis : Ormond's syndrome . Henry Ford llo.sp . M. Bull., 10 : 13, 1962 . 34 . HUTCH, J . A ., ATKINSON, R . C. and LOQUVAM, G . S . Pcrirenal (Gerota's) fasciitis . J. Urol ., 81 : 76, 1959 . 35 . COPRmGE, W . M., ROBERTS, L . C . and Huolles, J . Sclerosing lipogranuloma . South . M. J ., 48 : 827, 1955 . 36 . ORMOND, J. K . Bilateral ureteral obstruction due to envelopment and compression by inflammatory retroperitoneal process . J. Urol ., 59 : 1072, 1948 . 37 . ORMOND, J . K . Idiopathic retroperitoneal fibrosis : an established clinical entity . J. A . M . A ., 174 : 1561, 1960 . 38 . CHISHOLM, E . R ., Hurcn, J. A . and BoLOMEY, A. A . Bilateral ureteral obstruction due to chronic inflammation of the fascia around the ureters . J. Urol ., 72 : 812, 1954 . 39 . HACKETT, E. Idiopathic retroperitoneal fibrosis : a condition involving the ureters, the aorta, and the inferior vena cava. Brit . J. Surg ., 46 : 3, 1958 . 40 . RAPER, F . P . Idiopathic retroperitoneal fibrosis involving the ureters . Brit . J. Urol ., 28 : 436, 1956 . 41 . Editorial . Idiopathic mediastinal fibrosis . Brit . M . . I., 5306 : 720, 1962 . 42 . BARTHOLOMEW, L . G ., CAIN, J . C., WOOLNER, L . B ., UTZ, D . C . and FERRIS, D . O . Sclerosing cholangitis : its possible association with Riedel's struma and fibrous mediastinitis . New England J. Med., 269 : 8, 1963 . 43 . ALLEN, A. C . In : The Skin, p. 176 . C . V . Mosby Co., St . Louis, 1954 . 44 . RODBARD, S . Vascular modifications induced by flow . Am . Heart J., 51 : 926, 1956 . 45 . RODBARD, S . Physical factors in the progression of stenotic vascular lesions . Circulation, 17 : 410, 1958 . 46 . RoDnARD, S . Physical forces and the vascular lining . Ann . lot . Med., 50 : 1339, 1959 . 47. RODBARD, S . Stenosis in a deformable tube inhibited by outlet pressure . Am . Heart J., 57 : 544, 1959 . 48 . LULL, G . F . and WINN, D . F . Chronic fibrous mediastinitis due to histoplasma capsulatum (histoplasmal mediastinitis) . Radiology, 73 : 367, 1959 .