Mediastinum

Question 1

DDx for calcified lymph nodes

Answer 1

Common
- TB, sarcoid, silicosis, tx’d lymphoma
Uncommon
- Mets (thyroid, sarcoma, mucinous), amyloid, scleroderma, Castleman’s disease

Eggshell = silicosis and CWP, but may be more commonly seen in sarcoid due to higher prevalence

Question 2

Which anatomic structure produces the aortic nipple in radiographs

Answer 2

Left superior intercostal vein

Question 3

DDx anterior mediastinal (i.e. PREVASCULAR) mass

Answer 3

Thymic epithelial neoplasm (thymic cyst, thymoma, thymic carcinoma)
Germ cell tumour
Lymphoma
Thyroid goiter

*thymoma most common cause of ant. mediastinal mass - middle aged - MG association (30/10 rule) - 10 % of pt. with MG have thymoma, 30-50% of pt. with thymoma have MG

Question 4

List the different thymic tumours

Answer 4

Thymoma (most common, 30% invasive)
Thymic carcinoma (very aggressive, distant mets)
Thymic carcinoid (Cushing syndrome, MEN 1/2)
Thymic cysts (congenital, post radiation)
Thymolipoma

Question 5

Most common malignant GCT in the ant mediastinum

Answer 5

Seminoma (occurs exclusively in men)

Question 6

Most common type of lymphoma in the ant thorax

Answer 6

Hodgkins (NHL more common overall)

Question 7

DDx for avidly enhancing nodes

Answer 7

Castleman disease**, vascular mets
Vasc mets = RCC, thyroid, lung, sarcoma, melanoma
DDx: other non-nodal enhancing middle mediastinal lesions - hemangioma, paraganglioma

Castleman’s can be localized (resected) or multi-centric (tx’d with chemo)

Question 8

DDx for middle (i.e. VISCERAL SPACE) mediastinal mass

Answer 8

Lymphadenopathy
Aortic aneurysm
Enlarged PA
Foregut duplication cysts
Esophageal abnormalities - hernia, etc.

Question 9

DDx for post mediastinal mass (PARAVERTEBRAL SPACE)

Answer 9

• Neurogenic (most common - esp. in kids) - schwanommas, neurofibroma, ganglioneuroma, neuroblastoma
• Spine: extra-medullary hematopoiesis, lateral meningocele, paraspinal abscess, met, lymphoma

Question 10

Most common sympathetic ganglion tumours

Answer 10

• Ganglioneuroma (most common - benign)
• Neuroblastoma - think of this if under age 10!!
• Ganglioneuroblastoma (seen in older children)

Question 11

Most common site of esophageal perforation

Answer 11

Left side, distal esophagus

Question 12

Pulsion versus traction diverticula

Answer 12

• Pulsion - occurs from increased pressure (i.e. achalasia, distal obstruction) - pseudodiverticulum
  Epiphrenic variant located at right distal esophagus
• Traction - adjacent inflammatory process/nodes - true diverticula with all 3 layers