Transcript PD Lecture 1999 - Division of Neuropathology

Introduction to Gross Pathologic
Handling of Eye Specimens
Charleen T. Chu, M.D., Ph.D.
Division of Neuropathology
University of Pittsburgh
[email protected]
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
Front epithelial surface
– 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!
Cornea protocol
– Embed on both halves on cut edge made
from bisecting
– 3 H&E step levels
– 1 PAS
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
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.
2.
3.
4.
5.
Hold container up to light and examine lid to
identify transparent tissue
If not visualized, add drop of erythrosine to jar
and look again.
Bisect if flat; leave it wadded up if not.
Wrap in tea bag after final erythrosine staining.
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
ALWAYS call Dr. Chu or Kofler before handling
an oriented biopsy for the Eye bench
1. Determine closest margin
Generally 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.
© CT Chu, 2012
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
Or, submit superior sections in different
block as inferior sections
© CT Chu, 2012
Superior
Limbal
© 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 margin
is the corneal/limbal margin.
Ink this margin a different color!
Mucosal side
Wedge resection of eyelid
These should all go to ENT bench, but just for fun…
nasal
Use your anatomy knowledge to orient this right upper lid
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.
nasal
Skin side
© CT Chu, 2012
© CT Chu, 2012
Evisceration specimen
The
pigmented
uveal layer
lies
immediately
underneath
the sclera
and
completely
surrounds
the retina
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
Orbital exenteration and enucleation
© CT Chu, 2012
Do not attempt to gross without direct
supervision with Dr. Chu or Kofler
© CT Chu, 2012
Grossing an eyeball
l
l
Identify and orient
Measure
~ Big eyes
~ Little eyes
l
Describe lesions
~ size, radial (clockface) and A-P locations
l
l
l
Transillumination
Selecting plane to open eye
Internal anatomy and description of lesions
~ ?margins
Which eye is this? Where is the lesion?
© 2002 CT Chu
For more information on
© 2002 CT Chu
Melanotic Lesions, See
Blackboard on-line lectures
and quizzes.
“Ophthalmic Pathology” in
the Neuropath series
Measure
Describe Lesions
Clockface radial location. Dimensions. A-P location.
Distance from/involvement of key structures.
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
How should you sample margins for
suspected retinoblastoma?
A. Posterior vortex vein
B. Optic nerve - transverse in a separate
cassette
C. Ink entire eye and submit as usual
D. 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
Pagetoid spread is of prime
C. Pagetoid spread
importance to conjunctival melanomas
D. Epithelioid cytology
E. Location in uveal tract – does it involve
anterior angle/ciliary body/iris?
F. Extension to surface of eye