Mediastinum/airway/pleura Flashcards
Munier-Kuhn (tracheobronchomegaly) vs. Williams campbell syndrome
- Mounier-Kuhn - massive dilatation of trachea (>3cm)
- Williams Campbell - congenital cystic bronchiectasis - from a deficiency of cartilage in 4th-6th in order of bronchi.
Relapsing polychondritis is a/w what?
arthtritis
cartilage abnormalities of nose, ear, joints, larynx, trachea.
recurrent pneumonia.
Wegeners - C-anca
C is 3rd letter of alphabet, what 3 places does Wegners involve?
Upper airway, lower airways, and kidneys.
Tracheal narrowing due to Post-intubation stenosis vs. saber sheath
- Post-intubation stenosis is focal and hour-glass shaped
- Saber Sheath tracheal narrowing is a long segment, and seen in COPD
Describe the common variant - tracheal bronchus
RUL takes off from trachea. AKA pig bronchus.
- Anterior mediastinum location
- 2 compartments of anterior anatomy
- Space b/w sternum and pericardium
- Prevascular space: contains thumus, lymph nodes, and enlarged thryoid
Precardiac space: a potential space
Middle mediastiunum - boders and content
Anterior pericardium to posterior pericardium and posterior trachea
Ascedingin aortic arch, great vessels (SVC, IVC, PA). Trachea/bronchi, lymph nodes, phrenic, vagus, recurrent laryngeal nerves.
Posterior mediastinum - anatomy and contents
posterior pericardium/trachea to vertebral bodies.
Esophagus, descending aorta, azygos/hemiazygous, thoracic duct, vagus nerves, lymph nodes
Anterior junction line
- Location
- Number of pleura
- Abnormal convexity or displacemet suggests what?
- vertical line projecting over superior 2/3 of sternum
- 4 layers of pleura
- Anterior mediastinal mass.
posterior junctional line
- Location
- Number of pleura
- Abnormal convexity suggests what?
- projecting over trachea on frontal veiw. More superior than anterior junctional line.
- 4 layers of pleura
- posterior mediastinal mass
Posterior tracheal stripe - describe
Seen in lateral radiograph, interface of posterior wall of trachea w/ 2 pleural layers of medial right lung.
thickening of R and L paratraceal stripes may mean what?
pleural thickening, mass, adenopathy. Thickening of left paratracheal stripe may suggest medistnial hematoma
Right and left paraspinal lines abnormalitly may suggest
posterior mediastinal mass, hematoma, neurogenic tumor, aortic aneurysm, extramedullary hematopoiesis, esophageal mass, osteophyte
azygoesophageal recess
- Interface formed by what
- Distortion suggests what?
- contact of the posteromedial RLL and retrocardiac mediastinum
- esophageal mass, hiatal hernia, left atrial enlargement, adenopathy
AP window
- Boundaries
- Normal appearance on CXR
- Abnormal contour of AP widow may mean abnormality of AP structures. What are AP structuers.
- Aortic arch forms superior, anterior and posterior boundries. Top of PA is inferior border. Medial border is esophagus, trachea, left mainstem bronchus
- Shallow concave contour below aortic knob
- Adenopathy, nerve injury (left phrenic, vagus, or recurrent laryngeal), ligamentum arteriosum, left bronchial arteries.
Thoracic aortic aneurysm can also cause convexity of AP window
Retrosternal clear space abnormalities
Obliteration –> anterior mediastinal mass, RV dilatation, PA enlargement
Increase in RS clear space –> emphysema
what is aortic nipple?
Left superior intercostal vein (LSIV)
can be seen next to aortic knob
LSIV can be dilated as a collateral pathway in SVC obstruction
- Signs to suggest anterior mediastinal mass
- Signs to suggest middle mediastinal mass
Hilum overlay, deformation of anterior junction line. Obliteration of RS clear space
- Distortion of paratracheal stripes of convexity of AP window
- Distoriton of azygoesophageal recess, posterior junction line, paraspinal lines. These suggest paravertebral/posterior mediastinal mass.
Thymoma - mediastinal mass
- Age
- MG association
- Other Association
- how to pathologically classify if low risk vs. high risk?
- Histologic classifications
- WHO system
- Ages 45-60. (Dr. White uses rule of 40. If patien is over 40, its more likey a thymoma (rather than teratoma))
- 33% of pts w/ thymoma have MG, 10% of patients with MG have thymoma
- Red cell aplasia, hypogammaglobulinemia, paraneoplastic syndromes, malignancies
- low risk vs. high risk is based on histology. Invasive vs. non-invasive based on if capsule is intact.
- WHO system A, AB, B1, B2, B3, C subtypes
A: encapsulated
B: contain epithelial cells with a malignant component.
C: Carcinoma
Less common thymic lsesion (4)
Thymic carcinoma
Thymic carcinoid - A/w MEN1/2
Thymic cyst - may be secondarty to Radiation or AIDS
Thymolipoma
2 most common germ cell tumors in mediastinum
- Teratoma
- Seminoma (most common malignant anterior mediastinal GCT. Occurs in men).
What is the key to diagnosing thyroid mass in mediastinum?
Show continuity superiorly w/ the thyroid
Eggshell calcification lymph nodes are seen in what 3 disease in medistinu?
Silicosis, coal worker’s pneumoconiosis, sarcoidosis.
calcification in lymph nodes suggests prior granulomatous disease
Avid lymph node enhancement suggests what? (4)
Castleman disease, sarcoidosis, tb, vascular mets (RCC, thyroid, lung, sarcoma, melanoma)
Castleman disease
- AKA what?
- Key imaging finding
- treatment in localized disease
- Treatment in multicentric disease
- angiofollicular lymph node hyperplasia
- avidly enhancing adenopathy
- surgical excision
- multicentric disaee is a/w aids, lymphoma. Treated w/ chemo
Ddx for anterior mediastinal mass in
- Prevascular space (superior)
- Precardiac space (Cardiophrenic angle: inferior, in contact w/ diaphragm)
- Thymic lesion, GCT, thyroid, lymphoma
- epicardial fat pad, pericardial cyst, morgagni hernia (foramen of morgagni, right, anterior).
Middle mediastinal mass ddx (4)
Lymphadenopathy, ascending aortic arch aneurysm, Enlarged PA, foregut duplication cyst (includes bronchogenic cysts, esophageal duplication cyts, neuroenteric cysts.
Posterior mediastinal mass
- Peripheral neve tumors
- Sympathetic ganglion tumors
- Others
- Peripheral nerve sheath tumors (more common in adults): Schwannoma, neurofibroma, malignant peripheral nerve sheeth tumor
- Sympathetic ganglion tumors:more common in children/young adults): Ganglioneuroma, neuroblastoma, ganglioneuroblastoma
- Hiatal hernia, descending aortic aneurysm, extramedullary hematopoiesis, lateral meningocele, esophageal neoplasm, foregut duplicaiton cyst, paraspinal abscess.
Non-neoplastic Multifocal or diffuse tracheal thickening
- Two with sparing of posterior trachea (involve only cartilage)
- four with circumfrential thickening
- Relapsing polycondritis (cartilage abnormalities of ear/nose)
Tracheobronchopathia osteochondroplastica (nodularly calcified tracheal wall
- TB (smooth concentric thickeninging)
Amyloidosis (irregular thickening +/- calcs)
Wegner granulomatosis (subglottic tracheal thickening)
Sarcoid (hilar/mediastinal adenopathy and perilymphatic nodules).
Relapsing polychonritis
- Epidemiology
- Imaging features
- middle aged women
- smooth tracheal/bronchial wall thickening w/ sparing of posterior membraous trachea
- There may be increased attenuation at the tracheal wall.
TPO
- Say the name
- . Describe entity
- Imaging
- Tracheobronchopathia osteochondroblastica
- benign condition of multiple submucosal calcified osteocartilagenous nodules along tracheal walls
- Bulky calcifications w/ sparing of posterior membranous trachea.
- Endobronchial spread of TB is rare but may occur. Describe imaging findings
- Tracheal amyloid: imaging
- smooth concentric narrowing of a relatively long airway segment (>3cm). Usually involving distal trachea and proximal bronchi.
- Irregular narrowing of airways. Very rare
- Wegner granulomatous - describe involvement of airway
- Sarcoidosis and airway
- Large airway involvement seen in 20% of patients w/ Wegner. Manifests as subglottic tracheal stenosis w/ circumfrential mucosal thickening.
- Tracheal involvement is rare. Variable appearance ranging from smooth stenosis to nodular or mass-like appearance.
Focal non-neoplastic tracheal stenosis/wall thickening
- One iatrogenic cause, other rare causes
- Intubation/tracheostomy.
Behcet and crohn disease
Brochiectasis - irreversible dilatation of cartilage-containing bronchi
Final common pathway of mucus pluging, superimposed bacterial colonization, inflammatory response.
- 3 etiologies
- imaging findings
- Brochial wall injury (infection or inflammation)
Bronchial lumen obstruction
Traction from adjacent fibrosis
- tram tracks (thickened bronchial walls), Signet rign sign on CT (dilated bronchus adjacent to a normal pulum artery branch (should be 1:1 ratio)
Causes of bronchiectasis
mneumonic - CAPTAIn Kangaroo has Mounier-Kuhn
Cystic fibrosis
ABPA
Post-infectious
TB/atypical mycobacteria
Agammaglobulinemia
immunodeficiency
Kartagener
Mounier-Kuhn
Morphologic classification of bronchiectasis - rough gauge of severity
Cylindrical (least severe): mild bronchial dilatation
Varicose (moderately severe): Bronchi may be beaded/irregular
Cystic (most severe): bronchi are markedly enlarged and ballooned.
Broncholithiasis
Rare disorder - calcified/ossified material in bronchial lumen. Presents with nonproductive cough, hemoptysis, air trapping.
associated w/ microlithiasis
Relatinship of elastase and emphysema
Elastase is produced by macrophages. Extra elastase will destroy alveolar walls and cause emphysema. Alpha 1 antitrypsin normally neutralizes elastase.
centrolobular emphysema vs. paraseptal emphysema vs. Panacinar
Centrilobular emphysema: more in upper lobes, primarily effects center of secondary pulm lobule.
Paraseptal emphysema: usually subpleural inlocation, may predispose to pneumothorax
Panacinar (alpha 1 antitrypsin): affects entire acinus diffusely throughout the lung. more severe in lung bases.
Airway tumors (8)
- 2 are by far most common
- 6 others
- SCC, adenoid cystic
- Carcinoid, mucoepidermoid, tracheal lymphoma, mets, direct invasion, benign lesions
- Tracheal SCC appearance
- Adenoid Cystic carcinoma - describe. Patient age. Type of spread. CT appearance. PET appearance
- Poplypoid intraluminal mass. Contours of mass can be irregular, smooth, or lobulated. Can invade esophagus and cause TEF.
- Affects patients in 40’s. Low grade malignancy. No a/w smoking.
Perineural and submucosal spread.
On CT, looks like submucosal mass that infiltrates the tracheal wall and surrounding mediastinal fat. May also present as circumfrential thickening.
Avid PET uptake
Tracheal carcinoid- rare in adults, but most common endobronchial mass in children
- Carcinoid may rarely secrete hormones, such as __
- Occurs where?
- CT appearance. Differential.
- ACTH
- Distal to carina
- CT shows homogenous arterial mass w/ homogenous enhancement.
Differential dx of enhancing endobronchial mass includes mucoepidermoid carcinoma and rare entities like hemangioma and glomus tumor.
- Mucoepidermoid carcinoma - originates from tiny salivary glands - affects younger patients. What is CT appearance?
- Tracheal lymphoma ~ MALT, low grade malignancy.
- Endobronchial mets - mneumonic for most common mets: BReTh Lung
- Direct invasion by aggressive laryngeal, thyroid, esophageal, or lung cancer.
- benign lesions: name them
- round or oval endobronchial mass, indistinguishable from carcinoid.
- Breast, RCC, thyroid, lung
- Papillomas, chondroma, schwannoma, adenoma, hamartoma, hemangioma, lipoma, leiomyoma
Pleural malignancies (4)
mesothelioma
mets
MM - Rib-based lesions may appear to be pleural-based, although epicenter of mass is from rib.
fibrous tumor of the pleura
Mesothelioma
- 2 subtypes
- CT imagig
- Tx for less advanced disease vs. extrapleural pneumonectomy
- epithelial subtype (better prognosis), sarcomatoid and mixed subtypes
- nodular concentric pleural thickening, often w/ associated pleural effusion
- Pleurectomy and decortication for less advance disease
extrapleural pneumonectoy for locally invasive disease.
Fibrous tumor of the pleura
- How many are malignant?
- associations?
- 20-30% malignant
- Associated w/ hypoglycemia or hypertrophic pulm osteoarthropathy (although associations are uncommon).
- DDx for exudative effusinon
- Light’s criteria
- most common causes for chylothorax
- infectious, mesothelioma, mets, RA.
- Plerual protein:serum protein >0.5
Pleural LDH:Serum LDH >0.6
Plerual fluid LDH is >2/3 upper limits of normal for serum.
- associated with neoplastic obstruction, lymphangioleiomayomatosis (LAM)
Detection of a middle mediastinal mass
Distortion of paratracheal stripe or convexity of AP window.
Detection of a posterior mediastinal mass
distortion of azygoesophageal recess, posterior junctional line, or paraspinal lines.
