museum in pathology

1. MUSEUM IN PATHOLOGY

2. ● Pathological museums are in part historical,
representing the pioneer work of diagnosticians
and therapists.
● Presents records of the past states, now
infrequently encountered.
● Provide the students with basic material of their
current teaching

3. ● BASIC MUSEUM TECHNIQUES
– Reception
– Preparation
– Fixation
– Color restoration
– Preservation
– Mounting
– Special methods
– presentation

4. ● RECEPTION
– Source: specimen are mostly collected from
● Teaching hospitals – surgically resected specimen from
operation theatres.
● Necropsy specimen from postmortem room
● Research laboratories
– Specimen should be received with full details of the
patient and the lesion.

5. ● PREPARATION OF THE SPECIMEN
– Contact of the specimen with tap water –
commonest cause of inferior quality of specimen.
Resultant hemolysis greatly reduces the value of
preservation.
– Should be washed in saline and kept in saline
before demonstration. Drying ruins surface
appearance.
– Should not be kept in saline for more than 2 hrs as
autolysis sets in.

7. ● FIXATION OF THE SPECIMEN
– Objective : to preserve cells and tissue constituents
in as close to life like state as possible.
– Fixation stops autolysis and bacterial
decomposition, and stabilizing the cellular and
tissue constituents.
– Fixatives used are based on formalin fixative
technique.
– They are derived from Kaiserling technique and its
modification.

8. ● Keiserling recommended that the initial fixation
should be in neutral formalin ( KI) solution and
then preserving glycerine solution (KIII) for long
term display.
● These solution also preserve color.

9. ● Principle of fixation
– Specimen containing bile or stained by bile must be
fixed and stored apart from other specimen.
– Specimen undergoing fixation must not touch other
specimen or the sides of the jar; they must either lie
on washed lint or should be suspended by lenin
thread.
– Flat flaps of tissues like stomach, intestine etc. should
be fixed to cork board and left in formalin so that they
are not crumpled and irregularly fixed.
– Cystic cavities – if unopened, should be injected with
fixatives. Opened ones should be packed with cotton
wool.

10. – Solid viscera should be fixed by vascular injection.
For eg, brain is fixed by injecting fixative through
basilar artery.
– Lungs and limbs should be fixed by vascular
injection.

11. ● Fixation technique
– Most widely used techniques are modification of
method described by Kaiserling (1897)
– Originally 3 solutions were used
● First for fixing
● Second for restoring color
● Third as a mounting fluid.

12. Keiserling no I – fixing fluid
● Formalin 40% - 400 ml
● Potassium nitrate – 30 g
● Potassium acetate – 60 g
● Water up to 2000 ml
– Tissue is fixed in Kaiserling No. I solution for 24 hrs
to few weeks depending on the size of the
specimen.

13. Keiserling no. II solution
– The specimen is placed in 80% ethyl alcohol
solution for an optimal period for 1 hour ( up to 4 hrs
depending on the size of specimen), if the
specimen is discolored.
– If the specimen is left in alcohol for too long → the
color will fade, and the effect is irreversible.
– THIS STEP IS NOT REQUIRED IF MOUNTING
FLUID UDED IS SODIUM HYDROGEN SULFITE

14. ● COLOR RESTORATION
– The fixed specimen is transferred to a jar containing
industrial methylated spirit until the color is fully
restored.
– The alcohol penetrates the tissue rapidly.
– Floating specimen → cover with surgical gauze.
The vessel should be closed to prevent
evaporation.
– Color restoration is complete in 2 – 8 hrs,
depending on the size and character of the
specimen.

15. – Restoration can be achieved by adding reducing
agent – sodium hydrogen sulfite to the mounting
fluid (Pulvertaft, 1936).
– Specimen mounted show remarkably little fading
even after 25 yrs.

16. Original Kaiserling no. III solution
– Glycerin 500 ml
– Arsenious acid 1% in 200 ml
– Potassium acetate 250 g
– Thymol 2.5 g

17. Pulvertaft – Kaiserling mounting fluid III
– Glycerine 300 ml
– 10% sodium acetate 100 g
– 10% formalin 5 ml
– Tap water 1000 ml
● Camphor/ thymol – prevents the growth of moulds.
● Immediately before sealing 0.4% sod. Hydrosulfite is added.
● Solution should be filtered through paper pulp under
negative pressure to remove impurities.

18. ● Carbon monoxide has also been employed as
color -retaining agent. It gives brilliant contrast
color. Risks – poisoning, explosion. The colors
are unrealistic.
● Pure liquid paraffin can be used as final
mountant after color restoration with alcohol. It
reduces discoloration of mounting fluid by
pigments in the specimen

19. ● HOLLOW VISCERA
– Cut hollow viscera should be padded with cotton
wool.
– Uncut viscera can be pressure inflated. Eg
● Through urethra into the bladder.
● Through urethra into pelvicalyceal system
● Through trachea into the lungs.
● Direct injection in case of cysts
– The fixatives can be injected into such organs by
Higginson syringe or with conventional hypodermic
syringe.

21. ● PRESERVATION
– The specimen together with a duplicate label, is
wrapped in gauze or muslin and the label is
attached with a piece of linen thread.
– Specimens are preserved in a rectangular
earthenware tanks
– The fluid used can be Kaiserling fixing fluid I for a
period of six months.
– After 6 mths, the specimen should be treated with
80% alcohol to restore color.

23. ● MOUNTING
– Specimen are trimmed to desired size and shape
so that they fit in the jar. All unwanted and non
representative tissues are removed after careful
dissection.
– If the specimen do not remain in natural position
after removal of cotton wool packing, fill the cavities
with arsenious acid-gelatin.
– Regular cuts given keeping in anatomical position.

24. ● Friable specimen can be covered by thin layer
of arsenious acid- gelatin.
● Bile stained specimen are soaked in solution of
calcium chloride for 24 hrs to avoid
discoloration of mounting fluid.

25. ● Mounting procedure
– Museum jars and boxes
– Center plates
– Stitching specimens to center plate
– Fixing the center plate
– Filling and sealing

27. ● Factors affecting fixation
– Buffering
– Penetration
– Volume
– Temperature
– Concentration
– Time interval
– Position of the tissue

28. SPECIAL METHODS
– Maceration
● Used to demonstrate bony lesions eg. osteogenic sarcomas, osteomas
and tuberculosis
● Enables the preservation of even finest bony spicules .
– Calculi
● Calculi are cut in half with fine fretsaw and cut surface is polished with
sand paper.
● Dry mounting in closed jars
– Amyloid
● Iodine technique
● Congo red technique

29. PRESENTATION
– Museum specimen should be clearly labeled and a
system of cataloging should be employed which
allows easy and rapid access.

30. LABELING
– Rectangle of perspex sheet 1/16 th of an inch in
thickness which is cemented in the center at the
bottom of the outside of the box or the bottom of the
center plate.

31. THANK YOU