Introduction to Gross Pathologic Handling of Eye Specimens

Charleen T. Chu, M.D., Ph.D.Division of Neuropathology

University of Pittsburghctc4@pitt.edu

Eye Pathology Overview Grossing corneas

Penetrating transplants DSEK, DSAEK, Descemet’s membrane

Small eye specimens (< 4 mm) Eviscerations Eyelid or conjunctival lesions

Orient biopsy using surgical diagram or anatomical knowledge

Grossing an eyeball or exenteration

Penetrating or anterior lamellar keratoplasty

The classic “corneal button” A concave disc Measure, describe focal lesions

– Bisect near, but not through focal lesion, so it will not be lost on faceoff, but can be stepped into

Use a slicing motion that draws sharp new blade lightly across cornea– Do NOT use chopping motion – if cornea flattens,

the inside or back membrane which often has the diagnostic pathology will break and pop off!

Front epithelial surface

For histotechs: Embed both halves on the cut surface

from bisecting Green arrows show proper direction of cutting as step

levels are generated.

– We need sections through the central cornea, not tangential sampling of the edge

Cornea protocol– Embed on both halves on cut edge made

from bisecting– 3 H&E step levels– 1 PAS

Descemet’s Membrane Transparent basement membrane peeled from

back surface of cornea Synonyms: DSEK, DSAEK (Descemet’s

stripping and endothelial keratoplasty)

A sloppy surgeon may throw the donor cadaver button in the same container.– If you see a button, go ahead and gross it, but keep

looking for the patient’s membrane

DSEKs

1. Hold container up to light and examine lid to identify transparent tissue

2. If not visualized, add drop of erythrosine to jar and look again.

3. Bisect if flat; leave it wadded up if not.

4. Wrap in tea bag after final erythrosine staining.

5. Two H&E step levels and a PAS is sufficient

Histotechs: hold specimen in mold for a bit per Chris so paraffin cools around it before capping to prevent fall over

Corneal Biopsies Smaller than 4 mm in maximal dimension

Do NOT order cornea protocol or step levels – even if it is labeled “cornea”

Instead, use “Eye Biopsy” protocol for small specimens

Small eye specimens!!!!

Any specimen whose maximal dimension is <0.4 cm (4 mm), or has one dimension so small it may not survive processing.– Erythrosin mark– Submit wrapped in tea bag

Please order according to “Eye biopsy protocol” as described on next slide(would be nice if someone that knows how can

help set up this as a protocol in copath)

Eye Biopsy Protocol (<4 mm)

Instruct histology to minimize faceoff H&E PAS 4 blanks HHE in middle 4 blanks HHE at end

© CT Chu, 2012

ALWAYS call Dr. Chu or Kofler before handling an oriented biopsy for the Eye bench

1. Determine closest marginGenerally will section perpendicular to this

2. BEFORE cutting, flip over and ink deep surgical margins so that limbal margin (most important) can be distinguished from other margins.

Flip back over to lesion side and section

Preferred: line up pieces in order from superior to inferior on glass slide and fix with 1% agarose

Superior

Limbal

Or, submit superior sections in different block as inferior sections

© CT Chu, 2012

© CT Chu, 2012© CT Chu, 2012

Perpendicular vs. Shave Margins The CORNEAL or

LIMBAL margin is the most important margin.

Try to get neatly inked PERPENDICULAR sections to sample the corneal/limbal margin. Do not shave this margin.

Use the diagram to figure out which margin is closest to the cornea.

In this case, the lateral marginis the corneal/limbal margin.

Ink this margin a different color!

Wedge resection of eyelid

Ink surgical margins

Section perpendicular to closest margin

Arrange on glass slide and use agarose to keep in order,OR submit central sections and different tips (ink color coded) in different blocks.

Skin side

Mucosal side

Use your anatomy knowledge to orient this right upper lid

nasal

nasal

These should all go to ENT bench, but just for fun…

© CT Chu, 2012© CT Chu, 2012

Submit sections of cornea-scleral ellipse and sections sampling different areas of the uveal-retinal sac.

Order 1 H&E and 1 PAS per block

The pigmented uveal layer lies immediately underneath the sclera and completely surrounds the retina

Evisceration specimen

Orbital exenteration and enucleation

Do not attempt to gross without direct supervision with Dr. Chu or Kofler

© CT Chu, 2012© CT Chu, 2012

Grossing an eyeball Identify and orient Measure

~ Big eyes~ Little eyes

Describe lesions~ size, radial (clockface) and A-P locations

Transillumination Selecting plane to open eye Internal anatomy and description of lesions

~ ?margins

© 2002 CT Chu

Which eye is this? Where is the lesion?

For more information on Melanotic Lesions, See Blackboard on-line lectures and quizzes.

“Ophthalmic Pathology” in the Neuropath series

© 2002 CT Chu

Measure

Clockface radial location. Dimensions. A-P location. Distance from/involvement of key structures.

Describe Lesions

Transillumination – turn off lights!

© CT Chu, 2012

© CT Chu, 2012© CT Chu, 2012

© CT Chu, 2012

Opening eye

Draw blade in slicing motion rather than exerting pressure. Do NOT tilt towards optic nerve. Edge must remain same distance from optic nerve as from pupil.

Can you identify each subcompartment of the eye and describe the pathology?

© CT Chu, 2012

© CT Chu, 2012

© CT Chu, 2012

How should you sample margins for suspected retinoblastoma?

A. Posterior vortex veinB. Optic nerve - transverse in a separate

cassetteC. Ink entire eye and submit as usualD. Trabecular meshwork

All of these are prognostic factors for uveal melanoma that should be reported, except:

A. Largest base dimension (along sclera) and elevation into eye

B. Invasion into sclera

C. Pagetoid spread

D. Epithelioid cytology

E. Location in uveal tract – does it involve anterior angle/ciliary body/iris?

F. Extension to surface of eye

Pagetoid spread is of prime importance to conjunctival melanomas