Amyloidosis 3

AMYLOIDOSIS: PART 3: Morphology, Diagnosis, Special stains, clinical features & Prognosis

1. AMYLOIDOSIS 3

2. LEARNING OUTCOMES
•Organs involved in Amyloidosis
•Morphology & demonstration of Amyloid
•Gross
•Micro
•Routine stain
•Special stains
•Morphology of individual organs
•Clinical features, Diagnosis and Prognosis

3. Organs Involved in Amyloidosis
Secondary Amyloidosis
Familial Mediterranean fever
Heart, GIT, Respiratory tract,
peripheral nerves, skin and tongue
Kidney, liver, spleen, lymphnode
adrenals and thyroid
Primary Amyloidosis
Widespread.
Kidney, blood vessels , spleen,
respiratory tract and liver

4. Morphology of Amyloidosis

5. Macroscopy/ Gross examination
May or may not be visible
If the deposits are too much, then the organ is enlarged, gray, waxy
and firm.
Demonstration of amyloid in gross specimens
Oldest method, since the time of Virchow!
Apply Lugol’siodine
on the cut surface
The area containing
amyloid stains deep brown
Blue
Application of dilute
sulphuricacid
The above property is similar to staining property of starch! Hence
the name Amyloid!!!

6. Microscopic Examination
Hematoxylin & Eosin
Extracellular
Can be adjacent to basement membranes, if
the deposits are more, it encroaches on cells
and destroy
Can be perivascular or vascular
Amorphous, eosinophilic, glassy/hyaline like
Should be differentiated from collagen, fibrin etc
ROUTINE STAIN

7. SPECIAL STAINS
1. Congo Red Stain
Ordinary light
Amyloid appears red/pink
Polarizing microscopy
Apple Green Birefringence
Cross beta pleated sheet confirmation is the reason for this special
staining property!

8. Polarizing Microscopy
H & E Congo Red Stain

9. OTHER SPECIAL STAINS
2. Methyl & CresylViolet Metachromatic stains, pink color
3. ThioFlavinT & S Exhibits Flouroscence
4. AlcianBlue Stains blue, due to presence of
glycosaminoglycans
5. Periodic Acid Schiff (PAS)Stains Pink
6. Immunohistochemistry To distinguish AL, AA & ATTR types

10. Amyloidoisof different
organs

11. KIDNEY
•Most common
•Most serious
•Found most commonly in secondary amyloidosis .
•Accounts for one third cases of primary amyloidosis

12. •Gross examination:
•Can be normal size/ enlarged
•may be contracted/shrunken ( due to the narrowing of vessels
resulting in ischemia)
•Cut surface: Pale and waxy/ transluscent

13. Micro: Can involve any part of kidney. Glomerular lesions predominates.
Glomeruli: Appear as amor-
phousmaterial in mesan-
giumand capillary loops
Tubules : Deposits near
basement membrane. Later
seen in interstitium(red arrow)
Vessels: Deposits in the
walls of arterioles leading
to narrowing
Most common in secondary amyloidosis, Most serious
Gross:
Can be normal size/ enlarged, may be contracted. Cut surface: Pale and waxy/ translucent.
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14. Microscopy
Can involve any part of kidney! But glomerular lesions predominates.
They appear as
amorphous material
in mesangiumand
capillary loops
Tubules : deposits
near basement
membrane. Later
seen in connective
tissue between
them/interstitium
Vessels: deposits in
the walls of arterioles
leading to narrowing

15. Clinical features of Renal amyloidosis
•Can present with proteinuria.
•May be severe enough to result in Nephrotic syndrome
Increased
deposition in
glomeruli and
interstitium
Glomerular
ischemia and
atrophy of
tubules
Chronic Renal
failure

16. LIVER
Involved in most cases of systemic amyloidosis.
Initially appears
in space of
Disse
In between the cords
of hepatocytes
( RIBBON like pink
staining )
Compression of
cords
Shrunken
/atrophic
hepatocytes
Gross : Enlarged, pale & waxy
Microscopy
Clinically, functional impairment of liver is extremely rare.

17. SPLEEN

18. Gross : TWO PATTERNS
SAGO SPLEEN /NODULAR LARDACEOUS SPLEEN/DIFFUSE
Moderate enlargement.
C/S: transluscentwaxy nodules resembling
sago grains
Moderate to marked enlargement
C/S: map like areas resembling
Lard!
Micro: involves periarteolarlymphoid
sheath (white pulp) and hence they form
discrete deposits
Micro: Deposits start in the walls
of splenic sinuses,which
progresses till they form large
diffuse masses.

19. HEART
•Commonly associated with systemic amyloidosis
•Rarely as localized type ( Senile Cardiac Amyloidosis)

20. Gross :
May be enlarged.
Pale , translucent and waxy.
Nodules/Plaques of amyloid can
be seen in the epi/endocardium
Micro:
Seen in the coronary vessels or
surrounding them.
Around the myocardial fibes( Ring
Fibers)
Left atrium/interatrial septum in
Senile Cardiac Amyloidosis.
Clinical Features:
Can result in Cardiac Failure.
Subendocardialdeposition can interfere with conduction system leading to
arrhythmias .

21. Diagnosis of amyloidosis
•Despite strong suspicion, the diagnosis of systemic amyloidosis has to
be confirmed by tissue diagnosis/ histopathological examination
•Abdominal fat pad aspiration /biopsy is the preferred method for
diagnosis.
Simplicity, low cost, less complications and good accuracy
•Rectal and Gingival biopsy ( previously these were preferred) or labial
salivary gland biopsy.
•Localisedamyloiadosis: biopsy of the involved tissue and confirmation
by staining.

22. To know the type of Amyloid
•Immunohistochemistry is currently the standard method for amyloid
typing in routine practice.

23. Prognosis
•Generalised/systemic amyloidosis: the prognosis is poor.
•Myeloma associated amyloidosis has poorer outcomes.
•localized amyloidosis:localtreatment such as excision or laser removal
. Recurrence is common

24. LEARNING OUTCOMES
•Organs involved in Amyloidosis
•Morphology & demonstration of Amyloid
•Gross
•Micro
•Routine stain
•Special stains
•Morphology of individual organs
•Clinical features Diagnosis & Prognosis

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