cxr: lung mass - mediastinal mass
TRANSCRIPT
PROF DR MAGESHKUMAR SIR UNIT DR.VANITHA
AN INTERESTING X-RAY OF THE WEEK
65 years old male, chronic smoker presented with the c/o cough,
chest pain, breathlessness for the duration of 1 month H/o loss of wt + H/o loss of appetite +
In Lung or mediastenum?
Anterior / middle / posterior compartment ?
Narrows down your diagnosis
ACUTE ANGLE– so it is in the lung probably
If it is mediastinum - Which compartment? HILUM OVERLAY sign
helps here
Hilum overlay sign
an anterior mediastinal mass will overlap the main pulmonary arteries, therefore they will be seen within the margins of the mass
Principle of hilum overlay the proximal segments of the R and L
main pulmonary arteries lie lateral to the cardiac silhouette on PA film
With pericardial effusion or cardiac enlargement, this relationship is unchanged
Overlies aorto-
pulmonary window
and hilum
Hilum overlay sign
: this must be an anterior mediastinal mass because it overlaps rather than “pushes out” the main pulmonary arteries
Can easily see
anterior location
DD of anterior mass
The 4 T’s Thymoma
Generally over age 40 Teratoma
Generally under age 40 Thyroid
Goiter or neoplasm Terrible lymphoma
Eg 2
Sharp margin, overlies hilum
See well-defined anterior
mass
Middle Mediastinum
Between anterior and posterior mediastinum
Contains esophagus, trachea, aortic arch, lymph nodes and vessels, pulmonary vessels
Accounts for 30% of masses
M
DD of middle mass The 4 A’s
Adenopathy TB/fungal Sarcoid Neoplasm (bronchogenic CA, mets, lymphoma,
leukemia) Infections (EBV, AIDS)
Awful primary neoplasm Tracheal, esophageal
Aneurysm/vascular Abnormalities of development
Bronchogenic cyst- often between carina and esophagus
Pericardial cyst Esophageal duplication cyst
Eg 2
Mass posterior to trachea
Posterior Mediastinum
Contains thoracic duct, azygos and hemiazygos veins, lymph nodes, sympathetic chains, inferior vagus nerves
P
DD of posterior mass
Neurogenic tumors most common Sympathetic ganglion tumors:
neuroblastoma, ganglioneuroma Nerve root tumors: schwannoma,
neurofibroma Less common
Vertebral body abscess or tumor Vascular: aneurysm or hematoma Developmental: neurenteric cyst,
Bochdalek hernia
Can easily see posterior location
Is it in the lung or mediastenum?
If in mediastenum, which compartment?
Then what is the differential diagnosis of the mass?
Hilum convergenceTo distinguish between enlarged pulmonary artery and mediastinal mass
If branches of the pulmonary artery converge toward a central mass enlarged PA
If branches of PA converge toward the heart rather than the central mass mediastinal tumor