Med Imaging: Mediastinal Lesions

What are the three compartments of the mediastinum?

What are the three compartments of the mediastinum?

anterior, middle, posterior

What area of the mediastinum is located in front of the heart and great vessels?

Anterior

What area of the mediastinum contains the heart, pericardium, and major vessels?

Middle

What area of the mediastinum is located behind the heart and contains the esophagus and descending aorta?

Posterior

What are common mediastinal lesions?

thymomas, lymphadenopathy, neurogenic tumors, cysts

Where are thymomas typically found?

anterior mediastinum

Where does lymphadenopathy usually occur?

middle mediastinum, but can be any

Where do neurogenic tumors usually occur?

posterior mediastinum

Where are cysts usually found?

can be found in any compartment, bronchogenic often in middle

Which lesions are more likely to be malignant?

solid lesions

Which lesions are more likley to be benign?

cystic lesions

Presence of what suggest certain types of tumors or chronic infections?

calcification

What are fat lesions?

lipomas, usually benign

What do lesions in the anterior mediastinum do?

obliterate the retrosternal clear space

What do lesions in the middle mediastinum do?

cause widening of the mediastinum, can be associated w/ the hilum

What do lesions in the posterior mediastinum do?

displace the esophagus or vertebral bodies

Thymoma

Description: well-defined mass in the anterior mediastinum

Radiographic features: obliterates the retrosternal clear space, may show calcification

Lymphadenopathy

Description: enlarged lymph in the middle mediastinum

Radiographic Features: widening of the mediastinum, often associated w/ the hilum

Neurogenic Tumor

Description: a mass in the posterior mediastinum

Radiographic features: displacement of the esophagus or vertebral bodies, may show a paravertebral mass

Bronchogenic Cyst

Description: cystic lesion in the middle mediastinum

Radiographic features: well-defined, round mass, may show fluid levels

Clinical History and Symptoms to consider

pt Hx, cough like symptoms, dyspnea, chest pain

Imaging studies order

start w/ CXR → CT or MRI for detailed evaluated

When would you use a biopsy?

may be required for definitive diagnosis, especially for solid lesions

Localization

determine the compartment of the mediastinum

Characterization

assess whether the lesion is solid, cystic, calcified, or contains fat

Differential Dx

consider common lesions based on the compartment and radiographic features