BRANT: Chapter 11 - MEDIASTINUM AND HILA

Question 1

Name the sign used when the border of a superior mediastinal mass becomes indistinct as it extends beyond the level of the clavicles.

Answer 1

Cervicothoracic sign or thoracic inlet sign

This sign helps localize thoracic inlet masses if located anteriorly vs posteriorly/paravertebrally (since lung apex extends higher posteriorly than anteriorly)

Question 2

Diagnosis

Answer 2

Mediastinal teratoma

Question 3

19/F with chest pain and nonproductive cough

Answer 3

Castleman disease or angiofollicular lymph node hyperplasia

Question 4

Diagnosis

Answer 4

Azygos Continuation of the Inferior Vena Cava (IVC)

Question 5

Diagnosis

Answer 5

Bronchogenic cyst

Majority of bronchogenic cysts (80% to 90%) arise within the mediastinum in the vicinity of the tracheal carina

Question 6

Diagnosis

Answer 6

Pericardial cyst

Question 7

Answer 7

Enlarged Epipericardial Fat Pad

Question 8

Diagnosis

Answer 8

Hiatal hernia

Question 9

Diagnosis

Answer 9

Neurenteric cyst

When an enteric cyst has a persistent communication with the spinal canal (canal of Kovalevsky) and is associated with congenital defects of the thoracic spine (anterior spina bifida, hemivertebrae, or butterfly vertebrae), it is termed a neurenteric cyst

Question 10

Primary cross-sectional modality used to evaluate mediastinal masses.

Answer 10

Contrast-enhanced multidetector row CT (MDCT)

Question 11

MR is most useful for evaluation of mediastinal masses in the following circumstances, except:
a. Asessing lesions in patients who cannot receive iodinated contrast
b. Likely vascular lesions
c. Confirming the cystic nature of lesions that have high attenuation due to proteinacious contents
d. Distinguishing thymic hyperplasia from thymic neoplasms
e. All of the above justify the use of MRI

Answer 11

e. All of the above justify the use of MRI

Question 12

The following are indications to do PET, except:
a. Confirm increased metabolic activity in suspected malignancy
b. Assess response of mediastinal tumors to therapy, particularly lymphoma
c. Distinguish residual or recurrent tumor from fibrosis
d. All of above are indications to do PET

Answer 12

d. All of the above are indications to PET

Question 13

T/F: In contrast to other masses in the thoracic inlet, a tortuous vessel is usually associated with tracheal deviation toward the side of the mass, whereas most goiters and other inlet masses displace the trachea contralaterally.

Answer 13

True

Question 14

Most common thoracic inlet mass

Answer 14

Tortuous vascular structures

Question 15

Cystic or cavernous tumors that are comprised of dilated lymphatic channels and are most commonly discovered in infancy and is often associated with chromosomal abnormalities, including Turner syndrome, trisomies 13, 18, and 21

Answer 15

Cystic hygroma
(Lymphangioma)

Question 15

CT findings which suggest that the mediastinal mass is likely part of an ongoing thyroid pathology are the following, except:
a. Coarse calcifications
b. Cystic or necrotic areas
c. Baseline high CT attenuation
d. Intense enhancement (>25 HU) but rapid washout

Answer 15

d. Intense enhancement (>25 HU) but rapid washout

Intense enhancement (>25 H) as a result of the hypervascularity of most thyroid masses and prolonged enhancement (resulting from active uptake of iodine from contrast media) following intravenous contrast administration

Question 16

Second most common primary mediastinal neoplasms in adults after lymphoma

Answer 16

Thymomas (Thymic Epithelial Neoplasms)

Question 17

The average age at diagnosis of thymoma is

Answer 17

45 to 50

Question 18

Of patients with myasthenia gravis, ____ have a thymoma, while a larger percentage of patients with thymoma ( ____ ) have or will develop myasthenia.

Answer 18

10% to 15%
30% to 50%

Question 19

Modality that is best for characterizing thymomas and detecting local invasion preoperatively

Answer 19

CT

Question 20

T/F: Drop metastases to dependent portions of the pleural space are a recognized route of spread of thymoma that has invaded the pleura.

Answer 20

True

Question 21

60-year-old male with hypercalcemia. Diagnosis

Answer 21

Parathyroid adenoma

Question 22

Congenital unilocular thymic cysts are rare lesions that represent remnants of the ____ and contain thin or gelatinous fluid.

Answer 22

Thymopharyngeal duct

Question 23

It is defined as enlargement of a thymus that is normal on gross and histologic examination. This rare entity occurs primarily in children as a rebound effect in response to an antecedent stress, discontinuation of chemotherapy, or treatment of hypercortisolism.

Answer 23

Thymic hyperplasia

Question 24

T/F: Like most cases of true thymic hyperplasia, lymphoid hyperplasia does produce thymic enlargement.

Answer 24

False ## Footnote In contrast to most cases of true thymic hyperplasia, lymphoid hyperplasia does NOT produce thymic enlargement. Most patients with thymic hyperplasia have normal sized or diffusely enlarged glands on CT Chemical shift MR with in- and out-of-phase sequences can distinguish hyperplasia, which shows signal decrease on out-of-phase chemical shift imaging due to the presence of microscopic fat within hyperplastic tissue, from thymic neoplasms that do not decrease in signal intensity.

Question 25

Which MR technique can distinguish thymic hyperplasia from thymic neoplasm?

Answer 25

Chemical shift MR

Question 26

55-year-old woman, s/p chemotherapy for left breast cancer. Diagnosis

Answer 26

Thymic hyperplasia

Question 27

It is the most common primary mediastinal neoplasm in adults.

Answer 27

Lymphoma

Question 28

Of the various subtypes of NHL that present with mediastinal masses, ____ and ____ are the most common

Answer 28

Lymphoblastic lymphoma and diffuse large B-cell lymphoma

Question 29

Which of the following is true about lympoma? a. Lymphoma involving a single mediastinal or hilar nodal group is much more common in Hodgkin disease than in NHL. b. NHL most commonly involves middle mediastinal and hilar lymph nodes c. Juxtaphrenic and posterior mediastinal nodal involvement is uncommon but is seen almost exclusively in Hodgkin disease d. NHL involves the thorax in approximately 85% of patients at presentation.

Answer 29

b. NHL most commonly involves middle mediastinal and hilar lymph nodes ## Footnote a. NHL > HD b. True c. NHL d. 40%

Question 30

T/F: Calcification in untreated lymphoma is extremely uncommon, and its presence within an anterior mediastinal mass should suggest another diagnosis.

Answer 30

True

Question 31

T/F: On MR, untreated lymphoma appears as a mass of uniform low signal intensity on T1WIs and uniform high signal intensity or intermixed areas of low and high signal intensity on T2WIs. The areas of low signal intensity on T2WIs of untreated patients may be a result of foci of fibrotic tissue in nodular sclerosing Hodgkin disease.

Answer 31

True ## Footnote Patients with successfully treated mediastinal Hodgkin disease often have residual soft tissue density in the affected mediastinal compartments, with dystrophic calcification commonly seen within treated nodes In general, the appearance of high signal intensity regions on T2WIs more than 6 months after treatment should suggest recurrence.

Question 32

A key in distinguishing primary from metastatic mediastinal germ cell neoplasm is the presence of ____ lymph node involvement in metastatic gonadal tumors.

Answer 32

Retroperitoneal

Question 33

The most common benign mediastinal germ cell neoplasm is ____, comprising 60% to 70% of mediastinal germ cell neoplasms.

Answer 33

Teratoma ## Footnote Teratomas may be cystic or solid.

Question 34

____ is the most common type of teratoma seen in the mediastinum

Answer 34

Cystic or mature teratoma

Question 35

Most common malignant solid germ cell tumor, comprising 25% to 50% of such lesions

Answer 35

Seminoma ## Footnote Most germ cell neoplasms are detected in patients 20 to 40 years of age. While benign tumors have a slight female preponderance (female/male, 60%/40%), malignant tumors are seen almost exclusively in males

Question 36

Diagnosis

Answer 36

Mature teratoma

Question 37

Benign and malignant tumors arising from the fibrous, fatty, muscular, or vascular tissues of the mediastinum may present as mediastinal masses, most commonly in the ____ mediastinum.

Answer 37

Anterior

Question 38

Hemangiomas are benign tumors composed of vascular channels and may be associated with the syndrome of hereditary hemorrhagic telangiectasia. A pathognomonic sign on chest radiographs is the recognition of ____ within a smooth or lobulated soft tissue mass.

Answer 38

Phleboliths

Question 39

T/F: The presence of multiple bilateral mediastinal masses that distort the lung/mediastinal interface is relatively specific for lymph node enlargement.

Answer 39

True

Question 40

In general, abnormal lymph nodes are seen as round or oval soft tissue masses that measure ____ in their short-axis diameter.

Answer 40

>1.0 cm

Question 41

Most common source of metastases to the middle mediastinal nodes is ____

Answer 41

Lung cancer ## Footnote Paratracheal and aorticopulmonary nodes are most commonly involved.

Question 42

T/F: In sarcoidosis, the enlarged nodes produce a lobulated appearance on chest radiographs and CT, because the enlarged nodes do not coalesce.

Answer 42

True ## Footnote This is in contrast to lymphoma and nodal metastases, in which the intranodal tumor extends through the nodal capsule to form conglomerate-enlarged nodal masses Right and left paratracheal lymph nodes are typically involved

Question 43

Lymphoproliferative disorder characterized by enlargement of hilar and mediastinal lymph nodes, predominantly in the middle and posterior mediastinal compartments. Histologically, there is replacement of normal nodal architecture with multiple germinal centers and multiple small vessels with hyalinized walls that course perpendicularly toward the germinal centers to give a characteristic “lollipop” appearance on light microscopy. The vascular nature of these masses accounts for the intense enhancement seen on contrast-enhanced CT. Calcification within these masses has been described.

Answer 43

Angiofollicular or giant lymph node hyperplasia, known as Castleman disease (CD)

Question 44

It results from anomalous budding of the tracheobronchial tree during embryologic development, with characteristic low signal intensity on T1WIs and high signal intensity on T2WIs.

Answer 44

Bronchogenic cyst ## Footnote The majority of bronchogenic cysts (80% to 90%) arise within the mediastinum in the vicinity of the tracheal CARINA. The term foregut cyst has been used to describe those lesions that cannot be specifically characterized

Question 45

True of pericardial cysts, except: a. Arise from the parietal pericardium and contain clear serous fluid surrounded by a layer of mesothelial cells b. Most often, they arise in the posterior cardiophrenic angle, with left-sided lesions being twice as common as right-sided lesions c. CT typically shows a unilocular cystic mass adjacent to the heart d. Approximately 20% arise more superiorly within the mediastinum.

Answer 45

b. Most often, they arise in the posterior cardiophrenic angle, with left-sided lesions being twice as common as right-sided lesions ## Footnote Most often, they arise in the ANTERIOR cardiophrenic angle, with RIGHT-sided lesions being twice as common as left-sided lesions;

Question 46

Diagnosis

Answer 46

Achalasia

Question 47

A common cause of a mass in the inferior visceral mediastinum is a hiatal hernia. This results from a separation of the superior margins of the diaphragmatic crura and stretching of the ____ ligament.

Answer 47

Phrenoesophageal

Question 48

Most common structure within a hiatal hernia

Answer 48

Stomach

Question 49

What do you call a hiatal hernia which involves the folllowing structures: a. Gastric cardia b. Fundus

Answer 49

a. Sliding hernia b. Paraesophageal hernia

Question 50

When an enteric cyst has a persistent communication with the spinal canal (canal of Kovalevsky) and is associated with congenital defects of the thoracic spine (anterior spina bifida, hemivertebrae, or butterfly vertebrae), it is termed a ____.

Answer 50

Neurenteric cyst

Question 50

38/M with odynophagia. Diagnosis

Answer 50

Esophageal duplication cyst

Question 51

Diagnosis. Be specific

Answer 51

Paraesophageal hernia

Question 52

Diagnosis. Be specific

Answer 52

Sliding hernia

Question 53

Neurogenic tumors arising from the sympathetic ganglia include the following, except: a. Ganglioneuroma b. Ganglioneuroblastoma c. Paraganglionoma d. Neuroblastoma

Answer 53

c. Paraganglionoma ## Footnote Neurogenic tumors based on their origin: a. Intercostal nerves - schwannoma, neurofibroma b. Sympathetic ganglia -a, b, and d c. Paraganglionic cells - c

Question 54

2 of the most common neurogenic tumors in the following age groups: a. Children b. Adults

Answer 54

a. Neuroblastoma and Ganglioneuroma (sympathetic ganglia) b. Schwannoma and neurofibroma (intercostal nerves)

Question 55

True of neurogenic tumors originating from intercostal nerves: a. These are most commonly seen in children b. Schwannoma and neurfibroma are comprised of spindle cells that arise from the Schwann cell c. Neurofibroma is not encapsulated but with interspersed neurons d. Schwannoma is encapsulated with no interspersed neurons

Answer 55

b. Schwannoma and neurofibroma are comprised of spindle cells that arise from the Schwann cell ## Footnote a. These are more frequently seen in ADULTS b. True c. Neurofibroma - encapsuled + with neurons d. SchwanNOma - NOT encapsulated, NO neuronal elements

Question 56

39/F. Diagnosis

Answer 56

Neurogenic tumor (Schwannoma)

Question 57

15/F. Diagnosis

Answer 57

Neurogenic tumor (Ganglioneuroma) ## Footnote INTERCOSTAL NERVE TUMORS -ACUTE SYMPATHETIC NERVE TUMORS -BROAD These tumors generally present as elongated, vertically oriented paravertebral soft tissue masses with a broad area of contact with the posterior mediastinum. These findings may help distinguish these lesions from schwannomas or neurofibromas, which usually maintain an acute angle with the vertebral column and posterior mediastinum and therefore tend to show sharp superior and inferior margins on lateral chest radiographs. Both may erode the surrounding osseous structures

Question 58

These tumors that arise from neural crest or chromaffin cells that lie in proximity to the thoracolumbar sympathetic ganglia of the autonomic nervous system.

Answer 58

Mediastinal paraganglioma ## Footnote Anterior/Middle > Posterior

Question 59

3 of the most common primary sites of thoracic spinal metastases

Answer 59

Bronchogenic CA Breast CA Renal cell CA

Question 60

Determine if neoplastic, infectious, or extramedullary hematopoeisis a. Expansion and destruction of vertebral bodies, with sparing of intervertebral disks b. Presence of paravertebral mass centered at the point of maximal bone destruction c. Narrowing of the adjacent disk space and destruction of vertebral end-plates d. Expansion of the medullary space and cyst formation within long bones, ribs, and vertebral bodies, with associated lobulated paraspinal soft tissue masses

Answer 60

a. Neoplastic b. Infectious c. Infectious d. Extramedullary hematopoiesis

Question 61

T/F: Osteophytes are more common in the left due to inhibitory effect of the inferior vena cava

Answer 61

False ## Footnote Osteophytes are most commonly RIGHT sided because of the inhibitory effect of the pulsating descending AORTA on left-sided osteophyte formation.

Question 62

Most common posterior mediastinal mass in patients with neurofibromatosis

Answer 62

Meningoceles ## Footnote They represent an anomalous herniation of the spinal meninges through an intervertebral foramen, resulting in a paravertebral soft tissue mass. Chest radiographs typically reveal a round, well-defined paraspinal mass that is indistinguishable from a neurofibroma. Additional clues to the diagnosis include rib erosion, enlargement of the adjacent neural foramen, vertebral anomalies, or kyphoscoliosis. When a lateral meningocele is associated with kyphoscoliosis, it is usually found at the apex of the scoliotic curve on the convex side. Conversely, approximately two-thirds of patients with meningoceles have neurofibromatosis.

Question 63

Infectious or Neoplastic

Answer 63

Infectious (Discitis/Osteomyelitis of the Thoracic Spine) ## Footnote Disc space narrowing and vertebral end-plate destruction with a paravertebral inflammatory mass (arrows). Biopsy showed staphylococcal infection.

Question 64

Spontaneous esophageal perforation following prolonged vomiting is termed ____

Answer 64

Boerhaave syndrome ## Footnote In this condition, a vertical tear occurs along the LEFT POSTEROLATERAL wall of the distal esophagus, just above the esophagogastric junction, leading to signs and symptoms of acute mediastinitis.

Question 65

The sensitivity of the esophagram for detecting contrast leakage is highest when the study is obtained within ____ hours of the perforation. a. 6 b. 12 c. 24 d. 48

Answer 65

c. 24

Question 66

T/F: The hallmarks of chronic fibrosing mediastinitis are chronic inflammatory changes and mediastinal fibrosis.

Answer 66

True

Question 67

Most common cause of chronic fibrosing mediastinitis

Answer 67

Granulomatous infection, usually secondary to Histoplasma capsulatum

Question 68

Most commonly affected structures in chronic fibrosing mediastinitis

Answer 68

Superior vena cava (up to 75% of symptomatic patients) ## Footnote SVC syndrome results

Question 69

Most common finding in chronic fibrosing mediastinitis on MDCT

Answer 69

Enlarged LNs with calcification

Question 70

Most common cause of mediastinal hemorrhage: a. Injury to mediastinal vessels from blunt of penetrating thoracic trauma b. Iatrogenic trauma c. Spontaneous hemorrhage from coagulopathy or aortic rupture from aneurysm or dissection d. Bleeding mediastinal mass

Answer 70

a. Injury to mediastinal vessels from blunt of penetrating thoracic trauma

Question 71

54/M, asymptomatic. Diagnosis

Answer 71

Mediastinal lipomatosis

Question 72

Most comon source of pneumomediastinum and via what mechanism

Answer 72

Air from the lungs via Macklin effect

Question 73

Sign and diagnosis

Answer 73

Continuous diaphragm sign in pneumomediastinum

Question 74

It is the extrathoracic neoplasm with the highest incidence of intrathoracic nodal metastases

Answer 74

Malignant melanoma

Question 75

Characteristic feature in primary pulmonary tuberculosis in distinction to postprimary tuberculosis

Answer 75

Unilateral hilar or mediastinal lymph node enlargement

Question 76

T/F: The most frequent solid tumors producing bilateral hilar disease are small cell carcinoma of the lung, lymphoma, and malignant melanoma.

Answer 76

True

Question 77

Most likely diagnosis

Answer 77

Sarcoidosis

Question 78

The pattern of lymph node involvement in sarcoidosis has been termed the ____

Answer 78

1-2-3 sign, with 1 = right paratracheal, 2 = right hilar, and 3 = left hilar lymph node enlargement

Question 79

Eggshell calcification of hilar nodes is highly suggestive of this entity, although this may also be seen in sarcoidosis, histoplasmosis or amyloidosis

Answer 79

Chronic berylliosis

Question 80

T/F: The most common causes of a small hilum are atelectasis and resection of a portion of lung

Answer 80

True