Pathology

Question 1

What is amyloidosis?

Answer 1

Disease which involves deposition of abnormal fibrillar proteins known as amyloid in the extracellular tissue in a beta-pleated sheet structure

Question 2

What are the histological features of amyloidosis?

Answer 2

Staining with congo red shows apple green bifringence under polarised light
Violet-blue colour when exposed to iodine

Question 3

How can you classify amyloidosis?

Answer 3

AL - primary
AA - secondary
ATTR - hereditary autosomal dominant

Question 4

Describe the pathology of AL amyloid

Answer 4

Clonal proliferation of plasma cells producting amyloidal monoclonal immunoglobulins
Involves heart, kidney, peripheral nerves, skin, GIT

Question 5

Describe the pathology of AA amyloid

Answer 5

Secondary to chronic inflammation
Macrophages release interleukins that stimulate hepatocytes to secrete serum amyloid protein A

Question 6

Give examples of chronic inflammatory conditions in which AA amyloid can occur

Answer 6

RA
IBD
TB
Bronchiectasis
RCC

Question 7

What are the clinical features of AL amyloid?

Answer 7

Nephrotic syndrome
Restrictive cardiac disease
Peripheral neuropathy
Carpal tunnel syndrome
Poor absorption

Question 8

What are the clinical features of AA amyloid?

Answer 8

Hepatomegaly
CKD
Splenomegaly

Question 9

How is amyloidosis diagnosed?

Answer 9

Tissue biopsy - subcutaneous fat or rectal mucosa

Question 10

Where can isolated amyloid deposits be found in the body?

Answer 10

Thyroid
Larynx
Urinary tract
Aorta
Pituitary gland