Ch.12 - Recognizing Diseases of the Chest Flashcards
The middle mediastinum is home primarily to:
Lymphadenopathy from lymphoma and metastatic disease, such as from small cell carcinoma of the lung.
The posterior mediastinum is the location of:
Neurogenic tumors –> Either from the nerve sheath (mostly benign) or tissues other than the sheath (mostly malignant).
Incidental solitary pulmonary nodules (SPNs) less than … in size are rarely malignant.
4mm.
When clinical or imaging findings suggest malignancy, …% of SPNs in men >50 are malignant.
50%.
SNPs - Criteria on which an evaluation of benignity can be made include:
- Absolute size of the nodule upon discovery.
- Presence of calcification within it.
- The margin of the nodule.
- Change in the size of the nodule over time.
Bronchogenic carcinomas present in one of three ways:
- Visualizing the tumor itself.
- Recognizing the effects of bronchial obstruction such as pneumonitis and/or atelectasis.
- Recognizing the results of either their direct extension or metastatic spread to the chest or to distant organs.
Bronchogenic carcinoma most likely to obstruct + cavitate:
SCC.
Hematogenous spread –> Common sites of primaries:
- Colorectal.
- Breast.
- RCC.
- Head/neck.
- Bladder.
- Uterine.
- Cervical.
- Soft tissue sarcomas.
- Melanoma.
In lymphangitic spread of carcinoma, a tumor…:
Grows + Obstructs the lymphatics in the lung producing a pattern that is radiologically similar to pulmonary INTERSTITIAL edema.
–> Primaries that metastasize in this fashion –> Breast, lung, pancreatic.
Blebs, bullae, cysts, and cavities:
All air-containing lesions in the lung that differ in:
- Size.
- Location.
- Wall composition.
Anterior mediastinal masses - Thyroid goiter - What to look for:
The only anterior mediastinal mass that routinely deviates the trachea.
Anterior mediastinal masses - Lymphoma - What to look for:
Lobulated, polycyclic mass, frequently asymmetrical, that may occur in any compartment of the mediastinum.
Anterior mediastinal masses - Thymoma - What to look for:
Well-marginated mass that may be associated with myasthenia gravis.
Anterior mediastinal masses - Teratoma - What to look for:
Well-marginated mass that may contain fat and calcium on CT scans.
Sarcoidosis vs lymphoma - Lymphadenopathy:
Sarco –> Bilateral hilar + right paratracheal.
Lymphoma –> More often mediastinal + asymmetrical hilar enlargement.
Sarcoidosis vs Lymphoma - Nodes?
Sarco –> Bronchopulmonary nodes more PERIPHERAL.
Lymphoma –> Hilar nodes more CENTRAL.
Sarcoidosis vs Lymphoma - Pleural effusion?
Sarco –> About 5%.
Lymphoma –> About 30%.
Sarcoidosis vs Lymphoma - Anterior mediastinal adenopathy:
Sarco –> Uncommon.
Lymphoma –> Common.
Pancoast tumor:
- Soft tissue mass in the apex of the lung.
- MC SCC/Adeno.
- Frequently produces adjacent rib destruction.
- May invade branchial plexus.
- May cause Horner syndrome.
- On the RIGHT side, it may produce SVC obstruction.
Some common primary sites of metastatic lung nodules - Men:
- Colorectal.
- RCC.
- Head/neck.
- Testicular/bladder.
- Melanoma.
- Sarcoma.
Some common primary sites of metastatic lung nodules - Females:
- Breast.
- Colorectal.
- RCC.
- Cervical/endometrial.
- Melanoma.
- Sarcoma.
DDX 3 cavitating lesions - Thickness of the cavity wall:
Bronchogenic carcinoma –> Thick (means >5mm).
TB –> Thin.
Lung abscess –> Thick.
DDX 3 cavitating lung lesions - Inner margin of cavity:
Bronchogenic carcinoma –> Nodular.
TB –> Smooth.
Lung abscess –> Smooth.
Differentiating a mediastinal from a parenchymal lung mass on frontal and lateral CXR (4):
- Mediastinal masses originate in the mediastinum (makes sense, right?).
- If a mass is surrounded by lung tissue in BOTH the frontal + lateral projections –> Lies within the lung.
- GENERALLY –> The margin of a mediastinal mass is SHARPER than a mass originating in the lung.
- Mediastinal masses frequently displace, compress, or obstruct other mediastinal structures.