Aunt Minnies - Chest

Question 1

Answer 1

Intralobar sequestration

Part cystic and solid mass in posterior basal segment of right lower lobe w/large systemic vessel coursing through.

Intralobar drain via pulmonary veins and has no pleural covering, unlike extralobar.
They can contain focal areas of consolidation, which may have cystic areas or gas.

Question 2

Answer 2

Subacute hypersensitivity pneumonitis

Multiple ill-defined centrilobular nodules (sparing periphery), characteristic of subacute HP in cases of organic dust exposure.

Acute - diffuse, ill-defined airspace consolidation. After resolution, a fine nodular pattern is seen.
Subacute - patchy GGO and/or small ill-defined centrilobular nodules.
Chronic is characterized by fibrosis, findings of active disease may also be present

Question 3

Answer 3

Primary ciliary dyskinesia

CXR: Coarse, tubular opacities at both lung bases
CT: Varicoid and cystic bronchiectasis within right middle lobe, lingula and left lower lobe with air trapping and branching tubular opacities (mucoid impaction).

Basal predominant unlike CF.

Question 4

Answer 4

Congenital Bronchial Atresia

CXR: RUL mass with finger like projections superiorly
CT: V shaped tubular mass with distal air trapping

More common to affect apicoposterior left upper lobe segment

Question 5

Answer 5

Bronchopulmonary Foregut Cyst

Large, sharply marginated, fluid density subcarinal mass.

Bronchogenic may be intrapulmonary. Foregut cysts may be along the lower oesophagus.
Upper mediastinum or subcarinal can be either.

Question 6

Answer 6

LAM with renal AML

CXR: Hyperinflated lungs, subtle fine reticular opacities and cystic lucencies.
HRCT: Numerous discrete round cystic spaces of varied sizes with barely perceptible walls.
Fat containing lesion in L kidney.

Diffuse b/l thin walled cysts throughout both lungs in child bearing age –> diagnostic of LAM.
70% have extrathoracic findings.

Question 7

Answer 7

Pulmonary AVM & Brain Abscess

MR: Ring enhancing parietal lesion.
CT: Tangle of large, enhancing bessels in lingula.
3D demonstrates the architecture better.

Approx 70% associated with HHT

Question 8

Answer 8

RUL collapse secondary to central mass

Superior retraction of right hilum and horizontal fissure with mass causing reverse S configuration (Golden S sign).

In outpatient setting, lobar collapse likely represents a neoplasm until proven otherwise. In hospitalized patients, this is commonly due to mucus plugging

Question 9

Answer 9

Lymphangitic carcinomatosis

Nodular thickening of interlobular septa with thickened bronchovascular bundles.

Usually in adenocarcinomas, tumour is deposited peripherally by haematogenous spread, then grow back towards the hila by infiltrating pulmonary lymphatics.
Unilateral disease and pleural effusion strongly favours this over sarcoidosis.

Question 10

Answer 10

Aspergilloma

Fibrocavitary changes in upper lobes with dependent soft tissue mass in LUL cavity.
Zoomed image shows rounded mass with well defined superior border and thin rim of surrounding gas

Common causes of pre-existing cavity include TB, Sarcoid, Emphysema

Question 11

Answer 11

Amiodarone pulmonary toxicity

CXR shows cardiomegaly, transvenous pacemaker and automatic implantable cardioverter defibrillator patches.
Focal areas of increased opacity in RUL, better appreciated on CT as high attenuation consolidation (almost as high as enhanced aorta due to iodine in amiodarone).

Amiodarone lung toxicity is dose related, more likely in >400mg/day.

Question 12

Answer 12

Sarcoidosis

Bilateral hilar and right paratracheal, AP window and subcarinal lymphadenopathy on CXR.
CT shows bihilar adenopathy in addition to subpleural, peribronchivascular and perilymphatic nodules.

Subpleural and perifissural nodules help distinguish sarcoid from HP.
Smooth or nodular peribronchovascular thickening also features in sarcoid.

Question 13

Answer 13

Bilateral acute PE

1) central pulmonary arteries are enlarged and upper lobe oligaemia
2) Extensive clot in right and left pulmonary arterial system
3) Relative enlargement of the right ventricle compared to left
4) Better demonstration of LUL oligaemia

Often caused by thrombi from DVT in legs. CXR mainly to diagnose alternative pathology, but can show wedge shaped opacities at costophrenic sulci mainly (hampton hump), enlarged pulmonary artery or areas of oligaemia (Westermark sign).
RL/LV >0.9 results in significantly worse outcomes, whilest >1.5 is diagnostic of “Massive PE”

Question 14

Answer 14

Complicated silicosis (Progressive Massive Fibrosis)

1) Reticulonodular interstitial opacities in upper loves, and mass like consolidations around the hila.
2) Hilar masses with eggshell calcifications
3) Scattered tiny nodules best seen in posterior left lung, with peripheral emphysema related to progressive massive fibrosis, causing mass like opacities on CXR

In acute setting, acute silicoproteinosis can occur due to massive exposure - causing perihilar ground glass and consolidation in “craxy paving” pattern.
Classic silicosis can have simple or complicated forms.
Simple - punctate nodular opacities with upper lobe predominance
Complicated - coalescence of small nodules into masses >1cm in diameter (PMF) often with distal emphysema.
Eggshell lymph node calcifications also occur in pneumoconoisis, sarcoid and treated lymphoma.

Question 15

Answer 15

Asbestosis with round pneumonia

1) Pleural thickening and partly calcified pleural plaques. Subpleural arcuate and short lines are fainly seen.
2) and 3) (Separated by 3 years) show bronchi and vessels spiraling towards a LUL mass, subtended by thickened pleura and unchanged over 3 years\

Manifestations of asbestos exposure include pleural diseases (effusion, plaques, mesothelioma), and interstitial diseases (asbestosis).
Secondary feature of pleural thickening is helical atelectasis. Volume loss in involved lobe and comet tail appearance of vessels and bronchi around the mass are classic for helical atelectasis.

Question 16

Answer 16

Pulmonary hamartoma

Well defined nodule in right lower lbobe with mixed soft tissue and fat density.

Presence of popcorn calcification is highly specific but seen in less than 1/3 of plain films.
Observation of fat and calcium on thin section CT withina smoothly marginated mass <2.5cm is almost always pulmonary hamartoma

Question 17

Answer 17

Pulmonary Alveolar Proteinosis

1) Small, ill-defined opacities roughly 6-10mm (size of pulmonary acinus). Kerley B lines faintly seen in periphery. Subpleural oedema seen as thickening of minor fissure.
2) and 3) show GGO of 2ndary pulmonary lobule, outlined by smooth, mild interlobular septa.

PAP is characterized by lipoproteinaceous material accumulating in end air spaces.
CXR - ill defined acinar opacities with peripheral sparing. CT demonstrates “crazy paving” - ground glass opacity of 2ndary lobule surrounded by smooth interlobular septal thickening.
Bronchoscopy and lavage is needed for final diagnosis (positive for periodic acid-Schiff).
Rx is whole lung lavage

Question 18

Answer 18

Miliary TB

CXRs show numerous miliary nodules diffusely throughout both lungs, with more confluent and coalescent nodular opacities in upper lobes.
Malpositioned central line with tip in azygous vein.

Occurs due to spread from primary or post-primary TB. Miliary nodules not seen until 3-6 weeks after haematogenous dissemination, seen as 1-3mm well marginated nodules diffusely through lung parenchyma with basilar predominance.

Question 19

Answer 19

Fibrosing mediastinitis

1) Enlargement of right ventricle and hila
2) soft tissue attenuation throughout middle and posterior mediastinum with focal narrowing of lower lobe pulmonary arteries.
3) narrowing and obstruction to RLL artery better demonstrated

40% of cases found incidentally on CXR for other reasons.
Symptoms occur due to constriction of SVC, oesophagus causing cough, dyspnoea, haemoptysis or pulmonary venous or arterial obstruction.
Focal and diffuse subtypes.
Focal involves commonly rightt paratracheal and subcarinal nodes, associated with calcification
Diffuse - extensive soft tissue throughout mediastinum, narrowing bronchial or vascular structures.
MRI demonstrates low T2 fibrotic tissue

Question 20

Answer 20

Malignant pleural mesothelioma

1) Large partially loculated loculated left pleural effusion with volume lsos of left hemithorax.
2), 3) and 4) show circumferential pleural thickening including mediastinal pleura, invasion of parietal pericardium and chest wall invasion, in addition to loculated pleural effusion.

CXR - irregular, nodular peripheral pleural opaciries with assicated ipsilateral pleural effusion.
Encasement of the lung by tumour causes volume loss. Often extends into interlobar fissures.
Mediastinal pleural thickening, ipsilateral volume loss and unilateral effusions should raise suspicioun of mesothelioma.

Question 21

Answer 21

Pneumocystis jirovecii pneumonia

1) bilateral, symmetrical GGO involving middle and lower zones.
2) and 3) show diffucem central GGO without interlobular septal thickening

Most common opportunistic lung infection in HIV.
CXR reveals perihilar or diffuse symmetric reticular pattern or more granular/GG appearance.
Upper lobe disease seen in patients undergoing aerosolized prophylaxis.
CXR may be normal in severe immunocompromise, CT needed - patchy extensive GGO with parenchymal cysts in more advanced diserase.
Pleural effusions are rare

Question 22

Answer 22

Progressive systemic sclerosis

1) lower lobe predominate basilar and peripheral reticular opacities with diminished lung volumes. Enlarged central pulmonary arteries from pulmonary HTN.
2) and 3) show basilar and peripheral interlobular septal thickening, honeycombing and traction bronchiectasis. Dilated oesophagus

Pulmonary manifestations is interstitial fibrosus, which becomes more coarse and produces a reticulonodular pattern, usually basilar and peripheral distribution +/- honeycombing.
CT - GGO, honeycombing, bronchiectasis, septal and pleural thickening, subpleural cysts.
Usually UIP but NSIP can be seen too.
UIP or NSIP + oesophageal dilatation suggests Scleroderma

Question 23

Answer 23

Nonclassical Mycobacterium Avium Intracellulare

1) faint opacity obscuring right and left heart borders
2) Lateral shows coarse reticular opacities suggesting bronchiectasis
3) Varicoid bronchiectasis confined to right middle lobe and lingula

MAI is a common cause of pulmonary non-TB Mycobacterial disease.
Dx with clinical features and repeated positive sputum cultures.
Nonclassic form (Lady Windermere syndrome) is most distinctive - cylindrical bronchiectasis involving RML and Lingula, with centrilobular nodules and tree-in-bud appearance on CT.

Question 24

Answer 24

Alpha-1-antitrypsin deficiency

Large lower lobe bullae on CXR

AAT is in the differential for any emphysema in under 45s, those without emphysema risk factors or basilar predominant emphysema.
CXR - overinflation and attenuation of bronchivascular markings, lower lobe predominant (smoking related emphysema tends to involve upper lobes).

Question 25

Answer 25

Pancoast tumour ## Footnote 1) left superior sulcus tumour, invades chest wall surrounding left subclavian artery and destruction of left 2nd rib. 2) Chest wall involvement, extension along L subclavian artery and enlarged subpectoral node. 3) Shows better the left subclavian artery involvemewnt and rib destruction 4) Growth posterior to left subclavian artery along expected course of brachial plexus. Generally T3 lesions but invasion of brachial plexus, mediastinal structures or vertebral bodies leads to T4. CXR - apical cap or thickening, apical mass or bone destruction. MR preferred to CT to evaluate brachial plexus and chest wall and bone involvement

Question 26

Answer 26

Mature teratoma ## Footnote 1) and 2) demonstrate partly calcified anterior mediastinal mass 3) anterior mediastinal mass with striated calcifications mixed with soft tissue density and small focus of fat (arrow) Anterior mediastinum is commonest location for germ cell tumours after gonads. Mature (well differentiated) & Immature (immature mesenchymal tissue or neuroepithelial tissue or malignant components). Mature is most comon. Sharply marginated anterior mediastinal mass extending to one side of midline, may have calcification visible. CT - heterogenous, well defined masses with fat and calcium within anterior mediastinum is consistent with mature teratoma. Mature ones may erupt into pleural space, resulting in pleural effusion.

Question 27

Answer 27

Invasive aspergillosis ## Footnote 1) Ill defined nodule in right mid lung 2) presence of nodule with ill defined borders and GGO halo Invasive aspergillosis = involvement of normal lung tissue by aspergillus, causing tissue damage and necrosis, always in immunosuppressed. Occurs with invasion of small arteries, vascular occclusion and often infarction. CT shows characteristic nodule surrounded by ground glass halo. Nodules cavitate during healing process, with air crescend develops representing necrotic lung within the cavity (different to mycetoma in immunocompetent individuals).

Question 28

Answer 28

Pulmonary Langerhans Cell Histiocytosis (PLCH) ## Footnote 1) Subtle upper zone predominant reticular opacities with cystic lucencies. 2) pultiple varied size and shape cysts, some of which coalesce into larger, more bizzare cysts Usually occurs in younger smokers. Early disease shows small, bilateral symmetrical nodules in upper and middle zones. Progresses to reticulonodular abnormalities, then to cystic changes. Cysts have barely perceptible walls or are thick and nodular and can occur with nodules too in centrilobular distribution. B/L middle and upper zone nodules with sparing of lung bases in young smoker = PLCH

Question 29

Answer 29

Post primary TB - cavitatory TB with endobronchial spread ## Footnote 1) cavitatory lesion in LUL with multiple, ill-defined nodular opacities in both lungs. 2,3,4) thick walled cavity in LUL, with ,utliple small, centrilobular nodules and connecting linear opacities (tree in bud) of both lungs due to endobronchial spread. Primary TB usually involves mid-lower lobes and manifests as parenchymal disease, lymphadenopathy, pleural effusions, miliary disease or atelectasis. Post-primary (5-10%), usually due to reactivation of latent TB: earliest sign is patchy, ill-defined consolidation preferring apical or posterior upper lobes or superior lower lobes. Cavitation commonly occurs in areas of consolidation and occurs 50% of the time, with thick irregular walls and eventual complete lung opacification if left untreated. Endobronchial spread is common complication, causing tree in bud on HRCT.

Question 30

Answer 30

Trapped Lung ## Footnote 1) large, left pneumothorax without mediastinal shift and residual left pleural effusion. 2) and 3) thickening of visceral pleura and focal subpleural atelectasis Pneumothorax is most common complication of thoracocentesis. Trapped lung occurs when there is visceral pleural restriction in absence of active pleural disease, whereas Entrapped lung is where there is active pleural disease, e.g. empyema or malignant effusion. Both cause negative pleural pressures. Due to pleural restriction and adhesions, pneumothorax related to visceral pleural restriction can be seen on CXR. On CT, visceral pleural thickening can be seen when there is air in the pleural space.

Question 31

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