Path findings/details

Question 1

Touton giant cell

Answer 1

ring of nuclei surrounded by a foamy ring of lipid

-assoc/w/xanthogranulomatous dz

(Juvenile X-linked xanthogranuloma, adult-onset xanthogranuloma, adult onset asthma, periocular xanthogranuloma, necrobiotic xanthogranuloma, Erdheim Chester dz)

Question 2

Langhans giant cells

Answer 2

HORSESHOE shaped ring of nuceli around the cell

-assoc/w/GCA and sarcoidosis

Question 3

Homer Wright rosettes

Answer 3

retinoblastoma, neuroblastoma, medulloblastoma of cerebellum

Question 4

Psammoma bodies

Answer 4

found in many tumors, including ON meningioma, pituitary prolactinoma

Question 5

Rosenthal fibers

Answer 5

degenerating eosinophilic filaments, found in ON gliomas and other astrocytomas.

Question 6

Formalin

Answer 6

permeates at a rate of ~ 1 mm/hour. Since eye is ~24 mm in diameter, and the formalin needs to travel 12 mm from each surface to reach the center, it takes ~12 hours to fix a glove. Ideally the entire eye should be suspended in formalin for at least 12 hours prior to processing (usually > 24 hours).

Question 7

Demonstrate the presence of iron

Answer 7

-Prussian blue stain or Perls test

Question 8

von Kossa stain

Answer 8

• demonstrates the presence of calcium in tissues by staining calcium salts black (e.g. band keratopathy)

Question 9

Masson Trichrome

Answer 9

stain corneal stroma (hyaline) deposits in granular dystrophy
Also see in Reis Buckler (Absent BM replaced with sawtooth pattern of fibrocellular tissue)

Collagen stains blue; hyaline stains red

RED ON BLUE

Question 10

Alcian blue

Answer 10

classically used to stain the cornea stroma (mucopolysaccharide) deposits in macular dystrophy

Question 11

Antoni A and Antoni B

Answer 11

two histological patterns that occur in schwannomas (aka neurilemomas)
schwannomas - benign peripheral nerve sheath tumors that may arise de novo or as part of NF1/NF2

Antoni A = COMPACT groups of spindle cells within a tumor. often contain “verocay bodies” stacked arrangements of elongated palisading nuceli alternating with anuclear zones containing cell processes

Antoni B = lose meshwork of tissue interspersed with cystic spaces. Can indicate histological degeneration within the tumor.

Question 12

Gluaraldehyde

Answer 12

fixative = used for samples undergoing EM

Question 13

Ethyl alcohol

Answer 13

fixative for cytologic preparations

Question 14

Michel fixative

Answer 14

immunofluorescence specimens

Question 15

How are eyes cut?

Answer 15

Most eyes are cut so that the pupil and optic nerve (“PO section”) are contained in the same section. For globes with intraocular tumors, the globe is cut so that the center of the tumor (as outlined by previous transillumination) is in the PO section.

Question 16

frozen sections

Answer 16

Obtaining frozen sections for a tissue sample is an arduous and expensive process and should only be performed when appropriate. Valid indications for frozen sections includes: determining whether the margins are clear of tumor cells; providing fresh tissue for molecular genetics; to determine whether representative tissue has been biopsed for diagnosis; and to ensure tissue conservation (i.e. in the case of Moh’s surgery).

A surgeon is not supposed to order frozen sections and then proceed with the case before the results are obtained from the pathologist. Definitive diagnosis of a lesion requires permanent sections; i.e. it is inappropriate to produce a formal diagnosis with frozen sections alone.

Question 17

Amyloid SECONDARY protein structure

Answer 17

composed of different proteins - final structure: beta pleated sheet with nonbranching fibrils (75-100 angstroms)

Amyloid deposits: composed of abnormal (mutated) forms of the protein “transthyretin”

Question 18

% of K limbal stem cells that must be intact to replenish the K epi

Answer 18

25-33%

Question 19

Average dioptric power of the cornea

Answer 19

43.25

Question 20

Below what endothelial cell count would it be dangerous to do surgery?

Answer 20

1000 cells/mm^2

Question 21

Acid-Fast / Ziehl-Neelson

Answer 21

Mycobacteria; Nocardia

Detects granular dystrophy
Congo red
Amyloid stains orange
Detects lattice dystrophy
Crystal violet
Amyloid stains red-purple
Detects lattice dystrophy
Alcian blue
Acid mucopolysaccaride (blue)
Detects macular dystrophy
Colloidal iron
Acid mucopolysaccaride (blue)
Detects macular dystrophy

Question 22

Periodic acid-Schiff (PAS)

Answer 22

Basement membranes; fungi

Question 23

Gomori’s methenamine silver

Answer 23

Fungi

Question 24

Calcofluor white

Answer 24

Acanthamoeba; fungi

Question 25

Oil Red O

Answer 25

Neutral lipids (red-orange)
Must be frozen, non-fixed tissues

i.e. sebaceous cell

Question 26

Sudan black

Answer 26

Phospholiids; myelin

Question 27

Fontana-Masson

Answer 27

Melanin

Question 28

Prussian blue

Answer 28

Iron (hemosiderin)

ex: fleischer ring in keratoconus

Question 29

Alizarin red

Answer 29

Calcium (red-orange)

Question 30

Stains for calcium

Answer 30

von Kossa (black)
Alizarin red (red-orange)

Question 31

Luxol fast blue

Answer 31

Myelin (blue)

Question 32

Mucicarmine

Answer 32

Mucin (pink-red)

Question 33

Verhoeff Van Gieson, Movat’s pentachrome

Answer 33

Elastin (black)

Question 34

S100

Answer 34

Neural-crest derived (astrocytes, melanoma, etc)

Question 35

HMB-45, MART-1

Answer 35

Melanocytes