630 Postgrad Med J 2002;78:630–634 Postgrad Med J: first published as 10.1136/pmj.78.924.633 on 1 October 2002. Downloaded from 6 Shocket E, Simon SA. Small bowel obstuction SELF ASSESSMENT ANSWERS due to enterolith (bezoar formed in a duodenal diverticulum: a case report and review of the literature). Am J Gastroenterol An interesting case of the stomach or small bowel. Four types have 1982;77:621–4. been described based on their composition: 7 Frazzini VI, English WJ, Bashist B, et al. small bowel obstruction phytobezoars (containing fibre and cellulose), Small bowel obstruction due to phytobezoar formation within Meckel diverticulum: CT Q1: What is the diagnosis? trichobezoar, lactobezoars, and miscellaneous. The last group includes medications (hydro- findings. J Comput Assist Tomogr This is a case of mechanical small bowel 1996;20:390–2. scopic bulk laxatives, cholestyramine, non- 8 Maglinte DDT, Chernish SM, DeWesse R, et obstruction secondary to an enterolith/bezoar absorbable antacids, vitamin C tablets, and the likely source of which is jejunal diverticu- al. Acquired jejuno-ileal diverticular disease: Isocal tube feeds), parasites (Ascaris lumbri- subject review. Radiology 1986;158:577– losis 1–3 coides or roundworm), and synthetic fibre. A 80. Q2 : What is the differential case of carpet fibre bezoar forming at the site 9 Brettner A. Euphrat EJ. Radiological diagnosis? of a stapled intestinal anastamosis in a child significance of primary enterolithiasis. with pica has been described.3 In general, the Radiology 1970;94:283–8. This includes the various intraluminal causes formation of bezoars in the small intestine 10 Blake MP. Mendelson RM. Computed of small bowel obstruction such as: appears to be at sites of stasis such as blind tomography in small bowel obstruction. Australas Radiol 1994;38:298–302. • True foreign bodies: metallic, plastic. loops, tumours, and diverticulae (duodenal, 4–7 11 Burkill GJC, Bell JRG, Healy JC. The utility of • Food bolus. jejunal, and Meckels’). computed tomography in acute small bowel The incidence of acquired jejunal diverticu- obstruction.Clin Radiol 2001;56:350–9. • Gallstones. losis varies from 0.2% to 1.3% on necropsy 8 • Concretions. studies to 2.3% on enteroclysis. It is associ- ated in 33% to 75% of cases with diverticula Iatrogenic groin pain Q3: What are the other possible elsewhere in the gastrointestinal tract. En- Q1: What is the likely clinical teroliths that form in the proximal small complications of the primary disease diagnosis? of the small bowel? bowel contain bile salts and are frequently radiolucent whereas as many as a third of The triad of groin pain, hip flexion, and femo- The possible complications include: those that form in the ileum are radio-opaque ral neuropathy indicates iliopsoas sheath • Diverticulitis because of precipitation of mineral salts in an haemorrhage. This condition occurs in pa- 9 tients with inherited coagulation disorders, • Haemorrhage alkaline environment. The diagnosis is therefore rarely made on particularly haemophilia A, and in patients on • Obstruction: 1. True obstruction due to the preoperative plain abdominal radiograph. oral anticoagulants.12 Spontaneous haemor- enterolith, diverticulitis, adhesions associ- Computed tomography is the modality of rhage occurs deep to the iliacus fascia from ated with inflammation, volvulus about the choice for investigating patients with higher the iliacus or psoas muscles, blood tracking adhesions, and intussuception. 2. Pseudo- grades of small bowel obstruction where early from the retroperitoneal space into the pelvic obstruction or motility disorder. surgical intervention is contemplated.10 There extraperitoneal space. Occasionally massive bleeding can lead to signs of volume deficit. • Malabsorption due to stasis and bacterial is an increasing tendency to utilise computed The iliacus fascia invests the psoas major overgrowth. tomography to help define the cause, severity, and complications of small bowel obstruction and iliacus muscles and continues inferiorly • Fistulae. due to the unreliability of clinical signs to pre- as the posterior wall of the femoral sheath. • Asymptomatic pneumoperitoneum. dict accurately those patients requiring early This explains the association with femoral intervention.11 neuropathy, the nerve lying in the groove • Malignant tumours. This is an unusual cause of small bowel between the iliacus and psoas muscles. The Q4: What are the possible treatment obstruction that needs prompt diagnosis and predilection for the iliacus muscle is unclear. options? operative treatment. Q2: What lesion is shown on the The simplest surgical option for small or Final diagnosis computed tomograms (see p 627)? http://pmj.bmj.com/ crushable enteroliths is to milk them distally Enterolith causing small bowel obstruction. The computed tomograms shows a collection into the caecum and allow them to pass natu- behind the left iliacus muscle which displaces References rally. If this is not possible, the treatment of this anteriorly and separates it from the iliac this condition is an enterotomy to remove the 1 O’Malley JA, Ferucci JT Jr, Goodgame JT Jr. blade. The left iliopsoas muscle appears Medication bezoar: intestinal obstruction by enterolith with or without resection of the enlarged with heterogeneous attenuation in- segment of small bowel involved with diver- an isocal bezoar. Gastrointest Radiol 1981;6:141–4. ternally. ticulosis. Resection may be advocated if the 2 Villamizar E, Mendez M, Bonilla E, et al. diverticulosis is localised, and is recom- Q3: How should this condition be

Ascaris lumbricoides infestation as a cause of on September 29, 2021 by guest. Protected copyright. mended for the other forms of obstruction, intestinal obstruction in children: experience managed? haemorrhage, and patients with malabsorp- with 87 cases. J Pediatr Surg 1996;31:201–4 In our patient, warfarin was temporarily tion who do not respond to conservative man- (discussion 204–5). stopped. He was administered vitamin K, and agement. 3 Wang PY, Skarsgard ED, Baker RJ. Carpet thereafter started on heparin. The inter- bezoar obstruction of the small intestine. J national normalised ratio came down from Pediatr Surg 1996;31:1691–3. Discussion 7.2 to 2.0 within 24 hours. The pain resolved. The findings at laparotomy were as follows: 4 Klinger PJ, Seelig MH, Floch NR, et al. Small intestinal enteroliths—unusual cause of small There was some residual non-disabling thigh dilated loops of small bowel seen to mid- intestinal obstruction: report of three cases. Dis weakness at the time of discharge. ileum. Obstruction at this point was due to an Colon Rectum 1999;42:676–9. enterolith with collapsed distal bowel (see fig 5 Lorimer JW, Allen MW, Tao H, et al. Small Discussion 3 in questions (p 626) and fig 1 below). Two bowel carcinoid presenting in association with Haemorrhage into the iliacus and or psoas large jejunal diverticulae 12 and 24 inches a phytobezoar. Can J Surg 1991;34:331–3. muscles is a well recognised complication of from the duodenojejunal flexure seen which overanticoagulation, as well as of haemo- were palpably empty. The gallbladder was philiac disorders. The precise incidence and normal with no palpable gallstones. The initiating mechanism of this condition is enterolith was milked proximally and re- unclear. Two anatomical syndromes have been moved via a longitudinal antimesenteric described. enterotomy which was closed transversely, Spontaneous haemorrhage may commence without resection of the diverticular segment. either in the iliacus muscle, in which case At laparotomy it is essential to rule out the bleeding occurs deep to the iliacus fascia and other causes of enteroliths such as gallstones a femoral neuropathy may coexist. Alterna- (as evidenced by a cholecyst-duodenal/jejunal tively bleeding may commence in the psoas fistula) and to carefully palpate the entire major muscle initially or spread from the length of the small bowel including the diver- iliacus muscle to the psoas. In this case ticulae for further enteroliths. involvement of other components of the lum- Bezoars are masses of solidified organic or bosacral plexus, including the obturator nerve non-biological material commonly found in Figure 1 Enterolith. and the lateral femoral cutaneous nerve of the

www.postgradmedj.com Self assessment answers 631 Postgrad Med J: first published as 10.1136/pmj.78.924.633 on 1 October 2002. Downloaded from thigh, is likely. A similar clinical picture may which may be aphthoid, superficial, or deep tion, and dilatation proximal to stenosis, be produced by neoplastic infiltration of the are seen surrounded by normal mucosa. thickening of the mucosal folds, cobbleston- lumbosacral plexus. Tuberculoid granuloma is the most specific ing, discrete ulcers, or mural thickening. Long Pain is the presenting feature, involving the finding on histology apart from infiltration of segmental narrowing of the terminal ileum groin, and radiating to the thigh and leg. This lamina propria by lymphocytes and plasma was the only positive finding in the present is followed by gradually increasing paraesthe- cells with aggretates of lymphocytes near the case. siae and limb weakness. A flexion and lateral base of the crypts. In the present case, the Khwaja and Subbuswamy reported ischae- smooth and featureless mucosa, and inflam- mic strictures of the small intestine from rotation deformity of the hip may ensue. Pas- 4 sive hip extension is restricted and painful. matory cellular infiltrate of lamina propria northern Nigeria. The radiological features Delayed development of bruising in the groin suggests Crohn’s disease in remission. The are non-specific and simulate tuberculosis may occur. The pain may resolve in a week, patient has not been on any medication for and Crohn’s disease. Even at laparotomy, it may be difficult to differentiate this from with slower and often incomplete recovery of over four years. Crohn’s disease and tuberculosis. Hypotensive neurological function. In 10%–15% of cases 3 Discussion drugs can occasionally produce intestinal there may be no significant improvement. ulceration and stricture formation.5 There is little definitive guidance on man- Segmental areas of luminal narrowing of ileum referred to as ileal stricture is due to The barium infusion technique (enterocly- agement, as the literature is largely anecdotal sis) is an ideal investigation for study of the and based on case reports or small case series. rigid thickening and fibrosis of its wall result- ing in obstruction. It is a common complica- small intestine, both for focal lesions and for Overanticoagulation needs to be recognised extensive mucosal disease. In the best of and corrected. Computed tomography or tion of Crohn’s disease, tuberculosis, and intestinal ischaemia. A flare-up of inflamma- hands, the procedure gives an optimal ultrasound guided aspiration may be helpful, radiological-gross pathological correlation 4 tory process causes temporary intestinal especially if sepsis is suspected. and satisfactory evaluation of the extent, narrowing; when healing occurs with a scar or 6 The prognosis must remain guarded, as depth of the disease, and complications. residual neurological sequelae are possible fibrous tissue formation the obstruction is A histological difference between Crohn’s even where surgical treatment has been complete. The narrowing could either be disease and tuberculosis is not always possi- undertaken. With the increasing usage of circumferential and concentric or eccenteric ble. Supportive information only helps in therapeutic anticoagulation, doctors dealing and irregular in nature. On barium contrast making a diagnosis. In the case reported, the with anticoagulated patients need to be aware examination, these strictures typically appear peroperative findings of ileal stricture resem- of this clinical presentation. as segmental narrowing without normal bled Crohn’s disease and ileal tuberculosis; mucosal pattern and with smooth tapered terminal ileoscopy and histology was not Final diagnosis ends—referred to as the “string sign”. Stric- helpful. The possible diagnosis is Crohn’s dis- Iliopsoas sheath haemorrhage. tures themselves are painless and may not ease in “remission”. require treatment. But sometimes, these areas The patient under study has been asympto- Acknowledgement become so narrow and result in a partial or matic for four years and is not on any total obstruction. medication. Intervention in ileal strictures is We wish to thank Dr David Grant for selecting What is the pathophysiology of stricture necessary when an individual is symptomatic. and commenting on the radiographs. formation? The intestine can propel the Steroids, aminosalicylic acid preparations, References lumenal contents only when the lumen immunomodulators, and verapamil have been remains fairly wide enough. When there is used during the inflammatory phase; the lat- 1 Sasson Z, Mangat I. Spontaneous ilipsoas damage to the intestinal mucosa due to ter inhibits the smooth muscle cells’ response hematoma in patients with unstable coronary to intestinal injury and prevents collagen syndromes receiving intravenous heparin in inflammation, the smooth muscle cells of the therapeutic doses. Can J Cardiol intestine activate a complex chain of events, deposition. When the affected segment is 1996;12:490–4. involving a host of immune system compo- fibrosed and scarred, endoscopic balloon dila- 2 Chevalier X, Larget-Piet B. Femoral nents, for example, interleukin-1β. There is tation can relieve the obstruction. Surgical neuropathy due to psoas hematoma revisited. production and deposition of more than options include stricturoplasty and resection Report of three cases with serious outcomes. normal collagen at the site of injury. Scarring of the affected segment. Spine 1992;17:724–6. occurs, the layers of intestinal muscle thicken, Final diagnosis 3 Chad DA. In: Bradley WG, Daroff RB, et al, http://pmj.bmj.com/ eds. Neurology in clinical practice. Vol II, 3rd and the muscles no longer move smoothly and Crohn’s disease in “remission”. Ed. Oxford: Butterworth Heinemann, 2000: easily. In short, a stricture forms, compromis- 2040–1. ing the intestine’s ability to function effi- References 4 Merrick HW, Zeiss J, Woldenberg LS. ciently. 1 Click SN. Crohn’s disease of the small Percutaneous decompression for femoral An important differential diagnosis of ileal intestine. Radiol Clin North Am neuropathy secondary to heparin-induced stricture in the present case is Crohn’s disease, 1987;25:25–45. retroperitoneal hematoma: case report and 2 Herlinger H. The small bowel enema and the based on the peroperative findings of me- diagnosis of Crohn’s disease. Radiol Clin review of the literature. Am Surg senteric thickening and ileal stricture at ente- 1991;57:706–11. North Am 1982;20:721–42. roclysis. A featureless outline of a diseased 3 Ganesh P. Is Crohn’s disease rare in India? ileal segment, due to atrophy of the folds from Indian J Gastroenterol 2000;19:17–20. on September 29, 2021 by guest. Protected copyright. Terminal ileal stricture long standing inflammation, is not an uncom- 4 Khwaja MS, Subbuswamy SG. Ischemic mon finding in Crohn’s disease.1 In one series strictures of the small intestine in northern Q1: What does the small bowel 2 Nigeria. Trop Gastroenterol 1984;5:41–8. this was seen in 29% of cases ; the biopsy is 5 Brookes VS, Windsor CWO, Howell JS. enema show (see p 627)? not likely to be helpful in these situations. Ischaemic ulceration with stricture formation in The small bowel enema shows normal jeju- Crohn’s disease is being increasingly reported the small bowel. BrJSurg1966;55:583–5. num. The ileum is shortened in its distal por- from India.3 It is today included as an impor- 6 Goldberg HI, Cruthers SB, Nelson JA, et al. tion and uniformly narrowed with a smooth tant differential diagnosis for ileal tuberculo- Radiographic findings of the National sis. The strictures are caused by shrinkage of a Cooperative Crohn’s disease study. outline; the ileocaecal junction is well deline- Gastroenterology 1979;77:925–37. ated and the caecum is normal. tuberculous ileocaecal mass to form a fibrous constriction. In a country where both prob- Q2: What is the differential diagnosis? lems exist, distinction becomes difficult. Non- Lung nodules in a silver The differential diagnosis of ileal stricture response to antituberculosis treatment fa- polisher includes tuberculosis, Crohn’s disease, pelvic vours the diagnosis of Crohn’s disease. The inflammation, ischaemia, radiation enteritis, patient has not been treated for tuberculosis. Q1: What do the chest radiograph and carcinoid infiltration, lymphoma, and diffuse In Crohn’s disease, like tuberculosis, the HRCT of the lung show (see p 628)? enteropathy—that is, disorders where there is small intestine is the most common affected The chest radiograph shows nodular opaci- 1 inflammation, infiltration, or oedema of the site (80%). In the early stages of the disease, ties, predominantly in the upper lobes. The small bowel. History and clinical findings in the narrowing is due to oedema and spasm; HRCT lung images show diffusely distributed this case did not contribute to the diagnosis. with progression of the disease, fibrosis mani- centrilobular nodules without any evidence of fests as a lumenal narrowing. These findings fibrosis. Q3: How can you confirm the are also seen in tuberculosis. Few radiological diagnosis? signs are specific for Crohn’s disease. These Q2: What is the differential diagnosis Enteroscopy/terminal ileoscopy is the investi- include fissures, ulcers, sinuses, fistulae, and of the HRCT scan appearance and the gation of choice. In active Crohn’s disease, the asymmetrical involvement, skip lesions, and likely diagnosis in this case? terminal ileum shows patchy asymmetrical long longitudinal ulcers. Less specific findings The differential diagnosis of centrilobular and heterogenous mucosal lesions. Ulcers include luminal narrowing, stricture forma- nodules with diffuse distribution on HRCT

www.postgradmedj.com 632 Self assessment answers Postgrad Med J: first published as 10.1136/pmj.78.924.633 on 1 October 2002. Downloaded from 4 Sjogren B, Hansen KS, Kjuun H, et al. Box 1: Differential diagnosis of Learning points Exposure to stainless steel welding fumes and centrilobular nodules on HRCT lung lung cancer: a meta analysis. Occup Environ scan • Siderosis, baritosis, and stannosis are Med 1994;51:335. 5 Fletcher AC, Ades A. Lung cancer mortality types of benign pneumoconiosis with in a cohort of English foundry workers. Scand • Infectious bronchiolitis including tuber- radiographic dense opacities. J Work Environ Health 1984;10:716. culosis. • Siderosis, also called welder’s lung, 6 Akira M, Higashihara T, Yokoyama K, et al. Radiographic type p pneumoconiosis: • Pneumoconiosis (coal worker’s pneumo- buffer’s lung, or silver polisher’s lung is high-resolution CT. Radiology 1989;171:117. coniosis and siderosis). the most common type. 7 International Labor Office. ILO • Diffuse panbronchiolitis. • Usually asymptomatic, respiratory symp- classification of radiographs of • Vasculitis and vascular metastases. pneumoconiosis. Geneva: ILO Publications, toms may be present in smokers or if 1980. • Sarcoidosis. there is concurrent exposure to silica or • Respiratory bronchiolitis-interstitial lung asbestos. Spinal tumour with raised disease. • Centrilobular nodules with diffuse distri- • Hypersensitivity pneumonitis bution are seen on a HRCT lung scan. intracranial pressure • Diagnosis is made on radiological Q1: Based on history and clinical features and occupational exposure. examination what is the differential lung scan (see p 628) are infectious bronchi- diagnosis? olitis including tuberculosis, pneumoconiosis Differential diagnosis for raised intracranial (coal worker’s pneumoconiosis and siderosis), pressure with cauda equina syndrome include vasculitis and vascular metastases, sarcoido- present extracellularly in alveolar spaces and entities with lesions at multiple sites such as: sis, hypersensitivity pneumonitis, diffuse pan- walls as well as in macrophages.1 Slight bronchiolitis, and respiratory bronchiolitis- reticulin proliferation may be present in • Malignant meningitis, particularly interstitial lung disease (box 1). The diagnosis siderosis, but there is no collagenous fibrosis. lymphoma with root lesions. in this case was siderosis in view of the clini- If fibrosis is present, it is secondary to the • Neurofibromatosis. cal presentation, occupational history of pro- presence of crystalline silica. • Tuberculosis. longed exposure to iron oxide during silver Radiologically, siderosis presents as centri- polishing, and characteristic appearance of lobular opacities on HRCT with a uniform dis- • Metastases. centrilobular nodules on HRCT of the lungs. tribution throughout the lung fields with no Q2: What are the investigations conglomeration. Centrilobular opacities on required? Discussion HRCT lung can be divided into two types Siderosis (synonyms: welder’s lung, buffer’s according to size.6 The larger ones are seen as Imaging of the craniospinal axis and cerebro- lung, or silver polisher’s lung) is a non- sharply demarcated, rounded nodules and spinal fluid (CSF) analysis are required for fibrogenic or a “benign” form of pneumoco- these correspond to the q and r types of pneu- diagnosis. In our case, magnetic resonance imaging of the brain showed no expanding niosis due to the inhalation of iron particles. moconiosis (box 2) seen on the chest mass lesion, except for a small left parietal Iron dust is an inorganic, inert, mineral dust radiograph.7 The smaller ones, more frequent arachnoid cyst. CSF analysis was then done by with high radiodensity, which neither causes in number, are seen as relatively ill defined lumbar puncture. The fluid was xanthochro- substantial proliferation of reticulin fibres nor nodular or branching opacities, a few closely mic with an opening pressure of 30 cm H O. gives rise to collagenous fibrosis when re- spaced dots, or areas of low attenuation on 2 tained in the lungs.1 Occupations leading to CSF protein was 30 g/l, glucose 5.4 mmol/l, HRCT and represent radiographic type p × 6 siderosis involve exposure to iron oxide dust white blood cell count 40 10 /l, and red blood pneumoconiosis. The nodules are present dif- × 6 or fumes and include silver and steel polish- cell count 160 10 /l. This was suggestive of a fusely and bilaterally, but with upper lobe and CSF block in the spinal canal. ing, iron and steel rolling, steel grinding, elec- posterior predominance. tric arc welding, fettling, stripping and dress- Magnetic resonance imaging of the spine The differential diagnosis of centrilobular showed a intradural, extramedullary hetero- ing castings in iron foundries, boiler scaling, opacities on HRCT lung includes miliary http://pmj.bmj.com/ 1 geneously enhancing mass lesion at the and mining iron ores. tuberculosis, pneumoconiosis, metastases, D11–L2 level, which was hypointense on a T1 Patients are usually asymptomatic unless sarcoidosis, hypersensitivity pneumonitis, weighted image and hyperintense on a T2 there is concurrent smoking or contamination panbronchiolitis, and respiratory bron- weighted image (figs 1 and 2). of air with other chemicals such as silica or chiolitis-interstitial lung disease. Some radio- 2 asbestos. They may have a reddish coloured graphic features are characteristic of the Q3: What are the causes of bilateral 1 sputum due to exposure to these dusts. underlying disorder. In miliary tuberculosis, papilloedema without an expanding Siderosis is therefore essentially a “radiologi- the size of nodules is relatively uniform intracranial mass lesion? cal disorder”, due to the presence of very radi- throughout the lungs. In haematogenous The causes of bilateral papilloedema without odense opacities, but with no functional metastases, the metastatic nodules are usually on September 29, 2021 by guest. Protected copyright. 23 an intracranial expanding mass lesion in- impairment. Iron oxide exposure may be smooth, well defined, and round in shape. 45 clude: carcinogenic for the human lung. The emis- They are usually variable in size and do not sion of polycyclic aromatic hydrocarbons as show ill defined, fine centrilobular nodular or pyrolysis products of organic materials used branching opacities. A classical perilymphatic may be responsible, but requires further con- distribution of the nodules is seen in condi- firmation. tions like silicosis, sarcoidosis, lymphangitic The pathology of siderosis is characterised metastases, and amyloidosis. by perivascular and peribronchiolar aggrega- Patients with siderosis require no treatment tion of dark pigmented iron oxide particles and the radiological changes of siderosis may regress after cessation of exposure.3 The diag- nosis of siderosis should be considered in rel- Box 2: International Labor Office evant occupations with characteristic radio- classification of radiographs of logical abnormalities and absence of pneumoconiosis7 respiratory symptoms. Final diagnosis • Round opacities are classified accord- ing to size as: p, q, or r (p, up to 1.5 mm Siderosis. ∼ ∼ in diameter; q, 1.5 3 mm; r, 3 10 References mm). 1 Parkes WR. Inert dusts. Occupational lung • Irregular opacities are classified as: s, t, disorders. London: Butterworths, 1982: 113. Kusakai Y and u (fine, medium, or coarse respec- 2 . Metal induced lung disease: Figure 1 T1 weighted gado enhanced tively). lessons from Japan’s experience. J Occup Health 2001;43:123. sagittal magnetic resonance image of the • Combination of round and irregular as: 3 Morgan WKC, Kerr HD. Pathologic and thoracolumbar spine showing a well x, y, and z. physiologic studies of welder’s siderosis. Ann circumscribed 5 × 2 cm mass at D11–L2 Intern Med 1963;58:293. level.

www.postgradmedj.com Self assessment answers 633 Postgrad Med J: first published as 10.1136/pmj.78.924.633 on 1 October 2002. Downloaded from demonstrates a dumbbell shaped neoplasm Learning point measuring 40 × 30 mm arising from the right T2/T3 nerve root. It is of high signal intensity Consider a spinal tumour in a patient on T2-weighted images with a heterogenous with normal cranial imaging and a area of lower attenuation centrally. The lesion diagnosis of presumed benign measures 15 mm within the canal and 21 × 30 intracranial pressure. mm within the thorax and is expanding the neural canal at this level, consistent with a neoplasm of neural origin. The medial aspect of the tumour extends to the lateral border of Venous stasis by the tumour compression of the spinal cord, which is minimally displaced. spinal or medullary venous plexuses causing an unfavourable transarachnoid villous hy- Q2: What is the differential diagnosis? drostatic pressure is another proposed Mediastinal neoplasms encompass a long list mechanism.8 Leptomeningeal inflammation of histologically diverse lesions that can arise Figure 2 T2 weighted axial magnetic due to the toxic effect of CSF protein causing from a wide variety of mediastinal structures. resonance image of the thoracic spine compromise of CSF absorption is another In adults, most primary mediastinal neo- showing a hyperintense intradural mass, possible mechanism for raised intracranial plasms can be classified in one of four catego- more to the right, opposite the D11–L2 pressure.9 ries: thymus-derived neoplasms, neurogenic vertebrae. The spinal canal acts as an elastic reservoir tumours, lymphomas, or germ cell for CSF. With normal changes in physiological neoplasms.1 The differential diagnosis of masses in the posterior mediastinum includes • Hypertension. cerebral blood flow, the ability of the CSF to flow into and out of the spinal canal is neurogenic neoplasms (often neurofibromas • Collagen vascular diseases. thought to be important in maintenance of a and schwannomas), aneurysms of the de- • Guillain-Barré syndrome.1 constant intracranial volume. By compromis- scending aorta, oesophageal tumours, infec- ing this system spinal tumours may in fact tious processes including abscesses, and dis- • Idiopathic intracranial hypertension. reduce the capacity of this resorvoir and cause orders of the thoracic spine, such as sarcomas. • Spinal tumour.2–4 papilloedema.10 In adults, most posterior mediastinal tumours are of nerve sheath origin and are often Q4: What are the mechanisms/ Final daignosis benign and asymptomatic. processes which lead to raised Spinal ependymoma with intracranial hyper- Q3: What was the definitive intracranial pressure in patients tension. procedure? without intracranial mass lesions? References Given the likelihood of this lesion being a Bilateral papilloedema and diplopia without 1 Morley JB, Reynold EH. Papilloedema and benign neurogenic neoplasm, the patient pro- an expanding intracranial mass lesion in a Landry Guillain-Barré syndrome. Case report ceeded to a right posterolateral thoracotomy patients with spinal cord tumours have been and review. Brain 1966;89:205–22. with excision of the lesion. reported in the past. Raised CSF protein 2 Glasauer FE. Thoracic and lumbar intraspinal (causing delayed absorption of CSF due to tumours associated with increased intracranial Q4: Based on the radiological increased viscocity) and leptomeningeal in- pressure. J Neurol Neurosurg Psychiatry appearances, what potential flammation (probably due to the toxic effect 1964;27:451–8. 3 Tanaka K, Waga S, Shimosaka S. complication might arise if the lesion of protein secreted by the spinal cord tu- Papilloedema and spinal cord tumours. Surg was left untreated? mours) are the proposed mechanisms for the Neurol 1988;29:462–6. The MRI scan (see p 629) demonstrates that raised intracranial pressure in patients with 4 Ammerman BJ, Smith DR. Papilloedema and the tumour extends medially to the lateral spinal cord tumours. spinal cord tumours. Surg Neurol border of the spinal cord and is causing mini- 1975;3:55–7. Discussion 5 Matzkin DC, Slamovits TL, Genis I, et al. Disc mal displacement of the cord. If the tumour This patient underwent excision of the swelling. A tall tail? Surv Ophthalmol were to extend further medially, neurological http://pmj.bmj.com/ tumour and the biopsy was reported as a 1992;37:131–6. symptoms resulting from cord compression myxopapillary ependymoma. After this her 6 Schaltenbrand G. Normal and pathological might arise. Similarly, if the lesion was to fur- raised intracranial pressure and lateral rectus physiology of the cerebrospinal fluid ther deform the structure of the vertebral circulation. Lancet 1953;i:805–8. body, vertebral collapse might arise. palsy resolved. Bilateral papilloedema and 7 Gardner WJ, Spitler DK, Whitten C. diplopia without an expanding intracranial Increased intracranial pressure caused by Outcome mass lesion have been reported in patients increased protein content of cerebrospinal In view of the proximity of the lesion to the with spinal cord tumours. Common spinal fluid. N Engl J Med 1954;250:932–6. spinal cord, thoracotomy rather than thoraco- tumours associated with raised intracranial 8 Beduschi A, Culumella F, Papo I. scopic resection was considered the preferred on September 29, 2021 by guest. Protected copyright. Ependimomi della cauda con stasi papillare. pressure are ependymoma, schwannoma, surgical approach. The patient proceeded to a meningioma, neurofibroma, and glioma.35 Chirurgia (Milano) 1955;10:310. Arseni C right posterolateral thoracotomy in the fourth Common clinical features seen among the 9 , Maretsia M. Tumours of the lower spinal cord associated with increased intercostal space, and a soft yellow dumbbell patients in the previous reported cases in- shaped mass measuring 30 × 30 mm was dis- 2–5 intracranial pressure and papilloedema. J clude : Neurosurg 1967;27:105–10. covered in the right third intercostal space, • Bilateral papilloedema. 10 Martins AN, Wiley JK, Meyers PW. extending into the transverse foramen. The Dynamics of cerebrospinal fluid and the spinal lesion was excised and histological examina- • Diplopia. dura mater. J Neurol Neurosurg Psychiatry tion showed a partially encapsulated tumour • Raised CSF protein. 1972;35:468–73. composed of spindle cells in a loose fibrillary • Young, female patient. background. Antoni type A and B components were present with focal Verocay body forma- So far no definite cause has been explained A smoker with an apical tion. The histopathologist concluded that the for the raised intracranial pressure in these lesion was a benign intercostal schwannoma. cases. Whether it is because of the tumour mass The patient had an uneventful postoperative itself or because of the effects of the proteins Q1: Describe the abnormalities shown recovery. Four months after her operation, she secreted by these tumours into the CSF is not remains well, her symptoms have resolved, clear. in figs 2 and 3 (see p 629) and there is no radiological evidence of recur- Raised CSF proteins causing increased The chest radiograph suggests that the lesion rence of the lesion. viscocity could delay CSF absorption and in arises in the posterior mediastinum as it is turn cause raised intracranial pressure.6 Clog- visualised above the clavicle. Figure 2 is a Discussion ging of the pores of the semipermeable mem- computed tomogram of the thorax that dem- Neurogenic mediastinal tumours account for brane of the arachnoid villi by large protein onstrates a well marginated lesion extending approximately 20% of all mediastinal tumours molecules could also retard CSF absorption.7 from the neural canal at right T2/T3 level, with in adults and 40% in children. These tumours Raised CSF pressure causes increased pres- significant widening of the neural foramen at may be of nerve sheath, autonomic ganglia, or sure on the subarachnoid veins and leads to this level. There is no evidence of mediastinal paraganglionic origin and are generally lo- transudation of substances and further eleva- lymphadenopathy or lung parenchymal in- cated in the posterior mediastinum. Neuro- tion of protein. volvement. Figure 3 is a MRI scan that genic tumours of the mediastinum with an

www.postgradmedj.com 634 Self assessment answers Postgrad Med J: first published as 10.1136/pmj.78.924.633 on 1 October 2002. Downloaded from intraspinal component connected by a nar- Final diagnosis Discussion rowed segment in the intervertebral canal are Benign schwannoma, fourth intercostal The patient has a rib secondary from an generally described as dumbbell or hourglass space. obscure primary. Detailed gastrointestinal tumours. Tumours of nerve sheath origin tract evaluation and chest evaluation were classically present as paraspinal masses. These References non-contributory. tumours may be neurofibromas, schwanno- 1 Hoffman OA, Gillespie DJ, Aughenbaugh Moriwaki has described different types of mas, granular cell tumours, melanotic GL, et al. Primary mediastinal neoplasms rib tumours.1 These can be further classified schwannomas, or malignant schwannomas. (other than thymoma). Mayo Clin Proc Schwannomas are most often benign tu- 1993;68:880–91. as benign or malignant—the latter are often mours originating from the sheath of periph- 2 Tay HL, Swanston AR, Lumley JS. secondaries from a primary in the lung eral nerves and usually present as solitary and Glossopharyngeal schwannoma presenting as (35%).2 well encapsulated tumours. Most are asymp- gagging dysphagia. Postgrad Med J Micrometastases from gastro-oesophageal 1994;70:207–9. 13 tomatic and are detected incidentally on a malignancy has been reported. Oesoph- 3 Molenaar WM, Ladde BE, Schraffordt Koops routine chest radiograph. Schwannomas aris- H, et al. Two epithelioid malignant agogastric malignancy results in micrometas- ing from the intercostal nerve are well schwannomas in a patient with tases of ribs in 88% and in the iliac crest in described and may be multiple. Intrathoracic neurofibromatosis. Cytology, histology and 15%.3 These are independent of the histologi- schwannomas may also arise from other DNA-flow-cytometry. Pathol Res Pract cal type, nodal status, and neoadjuvant 184 nerves, such as the phrenic and glossopharyn- 1989; :529–34. therapy.3 Macrometastases is less common. geal nerves.2 Schwannomas are usually be- 4 Shamji FM, Todd TR, Vallieres E, et al. Central neurogenic tumours of the thoracic Yang et al described three sonographic nign but may occasionally be malignant. 4 35 patterns on cross section of abnormal ribs ; Malignant schwannomas have been described region. Can J Surg 1992; :497–501. 3 5 Ishida T, Maruyama R, Saitoh G, et al. ultrasound guided biopsy yields a 100% result in patients with neurofibromatosis. Thoracoscopy in the management of Of special concern in the management of without any complications and is an ideal intrathoracic neurogenic tumours. Int Surg method of confirming the diagnosis. neurogenic tumours arising in the thorax is 1996;81:347–9. spinal cord compression resulting from either Management depends on the histopathol- intraspinal lesions or vertebral body destruc- ogy and is often directed to the primary site. tion and collapse.4 Predictably, this complica- A man with a chest mass Large tumours, as in our case, requires surgi- tion makes for a more difficult surgical cal resection followed by chemotherapy. The excision. Intercostal schwannomas have been Q1: What is the interpretation of the patient is doing well six months after the successfully resected thoracoscopically. This biopsy specimen (see p 629)? resection. Failure to find the primary tumour technique may reduce hospital stay and mini- The specimen is an excision biopsy of the poses problems in management. Yetit remains mise postoperative complications, but is best tumour. Cut section of the mass shows a vari- controversial whether the prognosis improves reserved for lesions in which there is no when the primary tumour is identified by 5 egated appearance with areas of haemor- evidence of intraspinal extension. rhage, cystic changes, and necrosis. The histo- intensive diagnostic search as in the present The diagnosis of mediastinal tumours has logical findings are those of metastatic case.5 Overall the prognosis is poor. been aided by recent advances in computed adenocarcinoma. tomography, MRI, ultrasonography, radionu- Final diagnosis cleotide scanning, and fine needle aspiration. Q2: What are the different types of rib MRI is the preferred modality for imaging tumours? Adenocarcinoma of the rib. neurogenic tumours, because of its multipla- The bone metastases is either osteoclastic nar capability and high contrast resolution. References MRI can best demonstrate the number and (often squamous cell carcinoma), osteolytic Moriwaki S nature of the lesions (differentiating cysts (prostate carcinoma, poorly differentiated 1 . Histopathology of metastatic from neoplasms) and the intraspinal and adenocarcinoma, and breast carcinoma in bone tumours. Gan To Kagaku Ryoho 1987;14:1680–7 (translation). craniocaudad extent of the lesion, and thus young patients), intratrabecular, or of mixed type. 2 Allen MS, Mathisen DJ, Grillo HC, et al. determine the optimal surgical approach for http://pmj.bmj.com/ Bronchogenic carcinoma with chest wall patients. This technique is also especially use- invasion. Ann Thorac Surg 1991;51:948–51. ful for evaluation of the mediastinum of Q3: What is the mode of spread to the rib? 3 O’Sullivan GC, Sheehan D, Clarke A, et al. patients for whom the administration of iodi- Micrometastases in esophagogastric cancer: nated contrast material is contraindicated. In Bone marrow metastases is either via the high detection rate in resected rib segments. cases where intraspinal extension is demon- transpulmonary route, or the vertebral venous Gastroenterology 1999;116:543–8. strated, open thoracotomy is the more suitable system—the latter results in metastases to the 4 Yang GG, Wu HD, Yang PC, et al. 1 approach, as the likelihood of conversion to spine. The frequency of bone metastases via Sonographic patterns of ribs with tumour open thoracotomy during thoracoscopic re- the vertebral venous plexus without pulmo- involvement. J Formos Med Assoc

section is high. However, the definitive diag- nary metastases is 30% for carcinoma of the 1991;90:141–5. on September 29, 2021 by guest. Protected copyright. nosis of schwannoma requires histological prostate, 10.4% for uterus, 7.4% for breast, 5 Hillen HFP. Unknown primary tumours. examination. and 3.5% for stomach.1 Postgrad Med J 2000;76:690–3.

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