PEDIATRICS Section 6: Mediastinum Flashcards
The most common ANTERIOR mediastinal “mass”
Normal Thymus
Triangular shape of the thymus is called?
“Sail Sign”
Diagnosis? Sign?
the spinnaker sail sign, which is when pneumomediastinum lifts up the thymus.
what are the things that makes you think thymus is a cancer?
Abnormal Sizefor patients Age (really big in a 15 year old)
* Heterogenous appearance * Calcification
* Compression of airwayor vascular structure
In times of acute stress (pneumonia, radiation, chemotherapy, bums), the thymus will shrink. In the recovery phase it will rebound back to normal, and sometimes larger than before.
Thymic rebound (Can be PET avid)
Most common abnormal mediastinal mass in children (Older children and teenagers)
Lymphoma
Difference between Thymus and Lymphoma
Thymus is more in kids under 10,
Lymphoma is seen more in kids over 10.
When you see a mediastinal mass with calcifictaion, think of?
Teratoma
Can be seen in untreated lymphoma
What are the complications of Lymphoma?
Compresssion of SVC
Compression of Pulmonary veins
Pericardial effusion
Airway compression
This condition can appear very similar to Lymphoma (Soft tissue mass in anterior mediastinum). This cannot be differentiated on imaging alone
ALL (Acute lymphoblastic Leukemia)
a large anterior mediastinal mass arising from or at least next to the thymus.
Germ Cell Tumor (GCT)
What are the three Germ Cell Tumors?
Describe each.
- Teratoma
- Seminoma
- Non-Seminomanous GCT
GCT: Mostly Cystic, with fat and calcium
Teratoma
GCT: Bulky, solid and lobulated. “Straddles the midline”
Seminoma
GCT: Big and Ugly - Hemorrhage and Necrosis. Can get crazy and invade the lung.
Non. Seminomatous GCT
I say, Extra Gonadal Germ Cell Tumor, You say? (describe)
Klinefelter syndrome (47XXY)
They have small penises, they get male breast cancer, and as if things couldn’t possibly get worse… they get germ cell tumors in their chest.
300x risk of getting GCT
Pineal gland GCT can occur - vertical gaze palsy
In that case, they can’t even look up to the sky and say “Why God* ?! Why Me!? Why Klinefelter’s!?”
**God, Allah, Mother Earth, Celestial Deity not otherwise specified
What are the anterior mediastinal masses?
Thymus
Lymphoma
GCT
Thymic rebound
What are the middle mediastinal masses?
Lymphadenopathy
Duplication Cysts
Middle mediastinal lymphadenopathy is most often from?
Granulomatous disease (TB or Fungal) or from lymphoma
Causative agent of Mononucleosis
EBV (90%)
CMV (10%)
Classic scenario of Mononucleusis?
Adolescent with hilar adenopathy, splenomegaly, and fatigue.
Enumerate the types of mediastinal adenopathy
- Mononucleusis
- Primary TB
- Histoplasmosis
- Coccidiodomycosis
- Lymphoma
- Sarcoid