CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSISEISENBERG

1. 24Anterior Mediastinal Lesions on
Computed Tomography

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig C 24-1 Mediastinal lipomatosis. Abundant fat
throughout the superior mediastinum that has a
homogeneous attenuation similar to that of
subcutaneous fat. (Arrow, residual thymic tissue
or mediastinal lymph node; v, right innominate
vein; A, aortic arch.)44

4. • Fig C 24-2 Liposarcoma. Large, relatively inhomogeneous
mass in the right side of the mediastinum. Note that the
mass has a slightly higher attenuation than does the
subcutaneous fat. The mass extended into the right side of
the neck to involve the recurrent laryngeal nerve,
paralyzing the right vocal cord.44

5. • Fig C 24-3 Morgagni hernia. The right inferior
mediastinal mass contains large bowel and
omental fat. Focal eventration of the diaphragm
can be differentiated from a Morgagni's hernia by
the intact diaphragm in the former entity.44

6. • Fig C 24-4 Thymic cyst. Incidentally noted well-
circumscribed mass of fluid attenuation
(arrow).45

7. • Fig C 24-5 Thymoma. Slightly lobulated mass
(arrows) anterior to the main pulmonary
artery (MPA) in a patient with myasthenia
gravis.46

8. • Fig C 24-6 Thymoma. Enormous soft-tissue mass
in the anterior mediastinum with posterior
displacement of other mediastinal structures. No
difference in density can be seen between the
mass and the heart behind it.

9. • Fig C 24-7 Thymic carcinoma. Sagittal
reformatted image shows that the anterior
mediastinal mass is closely attached to the
pericardium with loss of the fat plane (arrow)
between the two entities, findings that
suggest pericardial involvement. There is also
a pericardial effusion.45

10. • Fig C 24-8 Thymic carcinoid. Lobulated,
heretogeneously enhancing mass. Loss of the fat
plane between the mass and the pericardium
suggests invasiveness.45

11. • Fig C 24-9 Thymic hyperplasia. Bilobed,
homogeneous soft-tissue lesion (arrows) in a
patient with Graves' disease.45

12. • Fig C 24-10 Retrosternal goiter. Soft-tissue
mass (arrow) extending into the anterior and
middle mediastinum.47

13. • Fig C 24-11 Ectopic parathyroid adenoma.
Small soft-tissue mass (arrow) in the anterior
mediastinum. (A, aorta; a, major branches of
the aorta; and v, brachiocephalic veins.)48

14. • Fig C 24-12 Mixed germ cell tumor. Contrast scan
shows a huge tumor that is primarily solid,
thought there is a relatively large cystic
component (arrow).49

15. • Fig C 24-13 Lymphoma. Large mass that fills the anterior medaistinum.
Note that the lung interfaces with the hilar vessels (arrow) and aorta
(arrowhead) are well preserved. Thus, on plain radiographs these middle
mediastinal structures were clearly seen through the mass (hilum overlay
sign), indicating that the lesion was either in the anterior or posterior
portion of the mediastinum.47

16. Fig C 24-14 Fibrosing mediastinitis. Soft-tissue attenuation mass
in the anterior mediastinum. A, aorta; S, superior vena cava.)50