Week 6: Respiratory System Pathology Part 2 Flashcards
1
Q
Carcinoma of the Lungs – Bronchogenic Carcinoma
A
- primary carcinoma of the lungs arises from the mucosa of the bronchial tree
- most common lung cancer
- a broad spectrum of appearances, it even mimics other processes, like pneumonia
- precise diagnosis from biopsy, often done under CT guidance
2
Q
Bronchogenic Carcinoma Radiographic Appearance
A
- solitary pulmonary nodule/small round mass (whiter than surrounding tissue due to increased density)
- show only by secondary changes (obstructed or compressed bronchus), atelectasis, pneumonia distal to obstructed bronchus (no air bronchogram sign)
- unilateral hilum enlargement
- cavitation from necrosis of neoplasm center – looks like lung abscess with thick wall & irregular and nodular inner wall
- bronchiolar (alveolar cell) cancer = well circumscribed solitary nodule, poorly defined mass, or multiple scattered nodules throughout both lungs
3
Q
Metastases to the Lungs
A
- cancer from elsewhere in the body may metastasize to the lungs through circulatory or lymphatic channels
4
Q
Metastases to the Lungs Radiographic Appearance
A
- nodules thought the lungs (small or large)
- are round or oval, well defined masses (cannonball lesions)
- military (snowstorm of tiny metazoic deposits)
- poorly defined, coarsened interstitial markings with irregular contours
5
Q
Pulmonary Embolism
A
- embolus (clot, air bubble, fat, debris) transported but the blood stream to the lungs na becomes lodged in the pulmonary artery circulation somewhere
- most arise from DVT of leg
- may be a complication from surgery of the abdomen or pelvis, pregnancy, oral contraceptives, tumors, vascular injury, lower extremity fractures
- can cause pulmonary infarct which may produce pleural effusion
6
Q
Pulmonary Embolism Radiographic Appearance
A
- CXR appears normal or non-specific
- may show lucency in affected part of the lung
- may show enlargement of ipsilateral Ian pulmonary artery
- if infarcted: shows as area of consolidation or Hamptons Hump (pleura based, wedge shaped density with rounded apex of the lung base) or may look like pneumonia
- Ct modality of choice
7
Q
Pulmonary Arteriovenous Fistula
A
- abnormal vascular communication from pulmonary artery to a pulmonary vein
- large one may cause shunting of blood from the arteries to the veins of the lung
- decreases oxygenation which can lead to cyanosis
- may have other vascular malformations (hereditary hemorrhagic telangiectasia)
8
Q
Pulmonary Arteriovenous Fistula Radiographic Appearance
A
- round or oval lobulated mass usually in the lower lobe area
- angiography used for diagnosis
9
Q
Atelectasis
A
- a condition in which there is diminished air within the lung associated with reduced lung volume (typically only part of lung)
- air is unable to enter the part of the lung supplied but the obstructed bronchus and air is absorbed into the bloodstream which cause lung to collapse
- causes: bronchial obstruction, due to neoplasm, foreign body, mucus plug, other or compression due to pneumothorax, pleural effusion, tumour, lung abscess bullae, improper ETT placement
- reversible and preventable with hyperventilation and incentive spirometry treatment
10
Q
Atelectasis Radiographic Appearance
A
- localized increase in density seen as thin platelike streaks or lobar collapse
- displacement of lobar fissures which shift and bow to match contour of collapsed segment
- secondary signs: elevation/tenting of ipsilateral hemidiaphragm (on collapsed side)
- displacement of heart, mediastinum and hilum towards collapsed side
- compensatory overinflation of remaining part of affected lung
11
Q
Acute Respiratory Distress Syndrome (ARDS) - Adult
A
- severe, unexpected, life threatening acute respiratory distress where the lung structure breaks down and there is a massive leakage of cells and fluid into the interstitial and alveolar spaces which cause the lung to fail with fluid
- respiratory impairment causes severe hypoxemia (blood oxygen levels too low)
- from a variety of disorders such as non-thoracic trauma, drug overdose, severe pulmonary infection, aspiration or inhalation of toxins/irritants BUT not no underlying lung disease
12
Q
Acute Respiratory Distress Syndrome (ARDS) - Adult Radiographic Appearance
A
- heart size usually remains normal
- ill defined alveolar consolidation scattered thought lungs
13
Q
Foreign Bodies
A
- may be aspirated, inhaled or penetrated
- in respiratory area, usually aspirated
- intrabronchial usually in young children
- usually lower lobes, right ore than left
14
Q
Foreign Bodies Radiographic Appearance
A
- may see obstructing item if radiopaque
- may cause complete obstruction of major bronchus leading to reabsorption of trapped air, alveolar collapse and atelectasis of segment or lobe
- heart and mediastinum may shift to affected side with elevation of that hemidiaphragm (ipsilateral)
- partial bronchial obstruction maybe seen as hyperinflation (air trapping)
- heart and mediastinum shift to normal contralateral side (during deep expiration and returns to normal during inspiration) (seen if using fluoro)
- may be inhalation/exhalation (insp/exp) CXR for aspiration because forced expiration shows the uncontracted lung well
15
Q
Mediastinal Emphysema (Pneumomediastinum)
A
- are within mediastinal space (space between lungs)
- may be spontaneous due to alveolar rupture and dissection of air along blood vessels to interstitial space in hilum and mediastinum (eg. coughing, vomiting, straining that increases intra-alveolar pressure) OR chest trauma (perforation, tracheobronchial tree, or spreading from other places)
- may cause spontaneous emphysema
