Mediastinum

Question 1

Large mass of tissue positioned between the pleurae of the lungs

Answer 1

Mediastinum

Question 2

Includes almost all components of the thoracic cavity except the —?

Answer 2

lungs

Question 3

above this line => superior & anything below => inferior

Answer 3

Plane of Ludwig

Question 4

Mediastinum is subdivided into 4 sections by the —?

Answer 4

Pericardium

Question 5

what are the 4 subsections of mediastinum?

Answer 5

Superior, anterior, middle & posterior

Question 6

Specialized lymphoid organ in the mediastinum, located between the lungs

Answer 6

Thymus

Question 7

What does Thymus produces to stimulate development of of T lyc?

Answer 7

Thymosin

Question 8

Why is cortex darker than the medulla on histology?

Answer 8

More lyc are in cortex than in medulla - lighter stained

Question 9

Referred to as “military specialists” & are made in bone marrow as pre-cursors then gets released into peripheral blood

Answer 9

T cells

Question 10

Only active until puberty where it undergoes atrophy

Answer 10

Thymus

Question 11

what kind of cells can be found in medulla & forms forms pearls on histology on Thymus?

Answer 11

Reticular Cells

Question 12

Epithelial cells are connected to each other by —– and the intermediate filament protein keratin is present in their cytoplasm.

Answer 12

Desmosomes

Question 13

One of the small bodies of the medulla of the thymus having granular cells at the center surrounded by concentric layers of modified epithelial cells

Answer 13

Hassall’s corpuscles: Pearls

Question 14

Lymphoma most commonly arises in which part of Mediastinum?

Answer 14

Anterior

Question 15

4 Ts of Mediastinum

Answer 15

Thymoma: Tumor of thymic cells
Thymic Carcinoma
T-Cell (Terrible) Lymphoma has worse prognosis
Teratoma/Germ Cell Tumors: squamous cells

Question 16

Dispersed lymphocytes with tight clusters of epithelial cells
Bland with no nucleoli
Spindle cell variant has elongated epithelial cells
Abundant cytoplasm
Also linked to Myasthenia Gravis (MG)

Answer 16

Thymoma

Question 17

What are the different subtypes of Thymoma & which is malignant?

Answer 17

A, AB, B1, B2, B3, C
C is highly malignant

Question 18

What are the two morphologies of a Thymoma?

Answer 18

Spindle cells or epithelioid cells

Question 19

What are some markers used for Thymoma?

Answer 19

TdT (T cells)
CD99 (lymphocytes)
Keratin
P63

Question 20

Name 3 differentials for a Thymoma

Answer 20

Lymphoma, seminoma, NSLC

Question 21

Children/teenagers
Monoclonal population of cleaved or non-cleaved lymphoblasts
CD3+

Answer 21

T cell Lymphoma

Question 22

Which lymphoma has a good prognosis & high cure rate?

Answer 22

HL

Question 23

Adrenal gland; most common pediatric tumor

Answer 23

Neuroblastoma

Question 24

Where do these tumors develop in mediastinum:
Neuroblastoma (pediatric tumor)
Ganglioneuroma
Schwannoma
Chordoma (tumor from spinal cord)
Metastatic Tumors

Answer 24

Posterior Mediastinum

Question 25

Children Also occurs in adrenal gland Benign Spindle cells Large round pleomorphic cells (ganglion cells) Granular cytoplasm IHC- S-100, NSE Benign

Answer 25

Ganglioneuroma

Question 26

Neoplasm arising form Schwann cells Well circumscribed masses attached to peripheral nerves, cranial nerves or nerve roots Comprised of densely packed spindle cells Palisading nuclei (Verocay bodies, Antoni A) Intermixed with looser myxoid areas

Answer 26

Schwannoma

Question 27

Almost always benign 2 areas: Antoni A & Antoni B Can occur anywhere in body but mainly in central part of body => mediastinum Spindle cell neoplasm Histology: Skin example

Answer 27

Schwannoma

Question 28

Areas are characterized by densely packed spindle-shaped Schwann cells arranged in a palisading pattern. Verocay bodies, which are alternating bands of cellular and acellular areas, may be present. Antoni A areas tend to be more cellular and organized. “Cellular”

Answer 28

Antoni A

Question 29

Areas are less organized and have a looser, myxoid, or cystic appearance. Schwann cells are less densely packed, and there may be areas of degeneration, hemorrhage, or cyst formation. “Cystic”

Answer 29

Antoni B

Question 30

Which marker will test (+) for Schwannoma?

Answer 30

S100

Question 31

Spindle cells with bent wavy nuclei Associated with dense fibrous stroma Rare to absent cytologic atypia May be cystic IHC- S-100, EMA, CD68, GFAP

Answer 31

Schwannomas

Question 32

-Where spine diffuses top of spine or bottom of spine -Multiple lobulated -Myxoid background: epithelial cells (islands); cytoplasm can be eosinophilic; cells have “bubbles” in them => physaliferous cells => multiple vacuolations Keratin & S100 makers Chains or islands

Answer 32

Chordoma