Thrall Chapter 33 Mediastinum

Question 1

1) How does the mediastinal space communicate with the retroperitoneal space?
a) Through the oesophageal hiatus
b) Through the aortic hiatus
c) Through the caudal vena cava foramen
d) It does not communicate with the retroperitoneal space

Answer 1

B

Question 2

2) At what age should the thymus have involuted in most dogs?
a) 6mo
b) 8mo
c) 12mo
d) 15mo

Answer 2

C

Question 3

3) Craniodorsal mediastinal masses typically cause deviation of the trachea in which direction?
a) Ventral and to the right
b) Dorsal and to the right
c) Ventral and to the left
d) Dorsal and to the left

Answer 3

A

Question 4

4) Which of the following region(s) to not drain to the cranial mediastinal lymph nodes?
a) C2 and C3
b) Muscles of the neck
c) Peritoneal cavity
d) Thyroid gland

Answer 4

C. they also drain muscles of the thorax and abdomen, oesophagus, trachea, scapula, thymus, ribs, coastal pleura, aorta, vertebrae, the last 6 cervical vertebrae, mediastinum, heart. also efferent (drains towards) lymphatic to other regional lns.

Question 5

5) Enlargement of the tracheobronchial lymph nodes usually causes deviation of the tracheal bifurcation in which direction on a lateral projection?
a) Caudoventral
b) Cranioventral
c) Caudodorsal
d) Craniodorsal

Answer 5

5) B but can rarely cause craniodorsal displacement

Question 6

6) Which of the following are not common causes of mediastinal lymph node enlargement?
a) Lymphoma
b) Primary lung tumours
c) Pyothorax
d) Bacterial pneumonia

Answer 6

6) B,C,D

Question 7

what are the white arrows pointing to?

Answer 7

cranioventral mediastinal reflection

Question 8

what are the black arrows pointing to?

Answer 8

thymus

Question 9

what are the white arrows pointing to?

Answer 9

caudoventral mediastinal reflection, a lot of fat in it as obese dog, see image for normal thin one

Question 10

mediastinal cysts are… (on radiographs)
a) usually close to the heart and ventrally located
b) more common in dogs
c) hard to distinguish from sternal lymph nodes
d) hard to distinguish from cranial mediastinal lymph nodes

Answer 10

A. they are more common in cats, further caudal than sternal LN and ventral compared to cranial mediastinal LNs. they are usually slow growing.

Question 11

what are the most likely differentials?

Answer 11

heart base mass, enlarged pulmonary artery, right atrial tumour.

Question 12

which mycotic diseases are more likey to cause mediastinal lymph node enlargement?
a) histoplasmosis
b) coccidiomycosis
c) blastomycosis
d) aspergillosis

Answer 12

b and c

Question 13

what are the likely imaging features of pulmonary lymphomatoid granulomatosis and disseminated histiocyte sarcoma?

Answer 13

pulmonary parenchymal disease and mediastinal lymphadomegaly.