Accumulation Flashcards
Definition of Tissue Accumulation
deposition of substance , either endogenous or exogenous in tissues
Types of Tissue Accumulation
1- Protein: Amyloidosis
2- Hyaline: Hyalinosis
3- Pigment
4- Pathological calcification
Def of Amyloidosis
It is the extracellular deposition of abnormal protein.
Chemical Nature of Amyloid
Amyloid light chain (AL) protein
Amyloid-associated (AA) protein
Amyloid light chain (AL) protein is produced by?
Produced by plasma cells from Ig light chain
Amyloid-associated (AA) protein is Produced by ?
by the liver during inflammation from proteolysis of SAA (serum amyloid-associated)
Classification of Amyloidosis
Localized Amyloidosis
Generalized (Systemic) Amyloidosis
Define Localized Amyloidosis and give examples
Limited to a single tissue or organ e.g. tongue (macroglossia).
Generalized (Systemic) Amyloidosis includes
Primary n secondary
Primary amyloidosis
Does it have a cause?
Where is it found?
The precursor protein is
There is no definite cause (idiopathic)
Found in multiple myeloma ( tumor of plasma cell)
The precursor protein is AL type
Secondary amyloidosis Is seen secondary to?
The precursor protein is
- Chronic inflammatory conditions e.g. tuberculosis & Rheumatoid arthritis.
- Some solid tumors e.g. renal cell carcinoma, Hodgkin Lymphoma
- The precursor protein is AA type
Pathogenesis of Amyloidosis
1- Production of large amount of normal protein.
2- gen mutation produce mutant proteins
Amyloidosis Gross picture?
The organ is enlarged, grey, firm and rubbery
Amyloidosis Microscopic picture?
Site of deposition
By H&E staining
By Specific stain
extracellular in basement membranes > wall of BVs
Pale pink
Congo red stain It stains amyloid > apple green by polarized microscope
the most specific stain for amyloid
Congo red stain
Effect of amyloid accumulation in tissue
- Pressure on cells
- Direct toxicity to cells e.g. cardiac cells
- Accumulation in vessel wall Leading to ischemia
Complications of amyloidosis
- Renal failure
- Heart failure
- Intestinal obstruction and malabsorption
Hyalinosis def
Intracellular / extracellular deposition of hyaline material.
Hyalinosis In H&E
Pale pink appearance
Types of Hyalinosis
1- Extracellular hyalinosis
2- Intracellular hyalinosis
Extracellular hyalinosis: seen in
- Old scar
- Wall of blood vessels in chronic disease e.g. DM
Intracellular hyalinosis seen in?
- Mallory body (in liver cells in Alcoholic patient)
- Russel body ( in plasma cells e.g. rhinoscleroma)
Difference between amyloidosis & Hyalinosis in desposition?
Extracellular deposition
Intracellular / Extracellular deposition
Difference between amyloidosis & Hyalinosis in structure?
Has definite biochemical structure
It has no definite structure