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Flashcards in Pigments and Minerals Deck (14)
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1
Q

Discuss staining methods for the demonstration of biogenic amines in tissue sections

A
  • Chromaffin or dichromate reaction can be used to stain biogenic amines in tissue sections (e.g. adrenaline or noradrenaline in the medulla of the kidneys)
2
Q

List of pigments and minerals that are introduced in the laboratory or not produced by the body

A
  • Chromaffin
  • Mercury
  • Formalin
  • Malaria
  • Asbestos
  • Silicon
  • Carbon
3
Q

List of pigments and minerals that are introduced in the laboratory or not produced by the body

A
  • Chromaffin
  • Mercury
  • Formalin
  • Malaria
  • Asbestos
  • Silicon
  • Carbon
4
Q

Adrenal chromaffin

A

What it is: A reaction of the amine (in this case, adrenaline or noradrenaline) with dichromate fixative

Appearance and location: Chromaffin presents in fine, yellow crystals with random distribution, but in the adrenal glands it appears in the medulla

Special stain used: Schmorl’s for lipofuscins (chromaffin appears black)

Birefringent: not birefringent

Significance: Can indicate if an individual has experienced chronic stress, patient may also experience high blood pressure

Avoidance: pigment can be avoided by using a different fixative or extracting the chromaffin with acid alcohol

5
Q

Ganglion lipofuscin

A

What it is: Breakdown product from oxidation of lipid and lipoproteins - wear and tear pigment

Appearance and location: Can be found in adrenals, heart, ganglia, GIT etc. but presents as fine, granular matter within the secreting cell (e.g. inside ganglion cells in spinal ganglion)

Special stain used: Schmorl’s for lipofuscins

Birefringent: not birefringent

Significance: demonstrates wear and tear of organ or organ systems (e.g. neuron/nerve damage in ganglion), can indicate possible morbidities later on

6
Q

Malarial liver

A

What it is: a malarial infection

Appearance and location: Pigment is located in RBCs that have been invaded by a malarial parasite, Kupffer cells, or macrophages that have tried to ingest the malaria. It presents as yellow-brown granular material

Special stain used: H&E and H&E with malaria and formalin removal

Birefringent: Birefringent in Kupffer cells

Significance: indicates malarial infection and damage to cells

Avoidance: Malaria can be removed from the tissue using alcohol ammonia

7
Q

Bile liver

A

What it is: A leakage of bile into the liver and ducts

Appearance and location: bright yellow-brown pigment in the bile ducts or hepatocytes

Special stain used: Fouchet for bile

Birefringent: not bi-refringent (if old formalin is used then some refringence may appear)

Significance: can indicate colystasis, hepatitis etc.

8
Q

Mercury in the kidney

A

What is it: a pigment introduced by fixation in mercury based fluids e.g. Formol

Appearance and location: granular black matter with random distribution in tissues

Special stain used: H&E and mercury removal with Lugol’s iodine and sodium thiosulphate (together, these form a water soluble compound that picks up residual iodine and removes mercury)

Birefringent: Collagen/scar tissue is birefringent

Significance: insignificant; introduced in the laboratory by mercury-based fluids

Avoidance: use NBF to avoid merc. pigment or extract with Lugol’s

9
Q

Mercury in the kidney

A

What is it: a pigment introduced by fixation in mercury based fluids e.g. Formol

Appearance and location:

10
Q

Silicon in the lungs

A

What is it: silicon shards from quartz can be inhaled by miners and accumulate in their lungs

Appearance and location: dumbell shaped structure, golden brown colour

Special stain: Perl’s prussian blue reaction (PBR)

Birefringent: yes for silicon shards

Significance: significant, can later cause fibrosis or silicosis

11
Q

Carbon in the lungs

A

What is it: carbon can be inhaled from cigarettes and accumulate in the lungs

Appearance and location: black granular material

Special stain: PBR

Birefringent: No

Significant: can cause anthracosis later on

12
Q

Gout in the knuckle

A

What is it: an accumulation of uric acid in the joints causes gouty arthritis, characterised by large round crystals around the joint

Appearance: in H&E, uric acid is colourless (has a slight pink blush), pockets of uric acid are surrounded by collagen and scar tissue in the knuckle

Special stain: no stain, only brought to dewax and then examined by polarising light. Gout is birefringent and appears as fine needle-like crystals

Birefringent: Yes, negative birefringence This is when the blue crystals are prependicular to the polarising filter, and yellow crystals are paralell to the filter. Positive birefringence is the inverse.

Significant: Yes; indicates gouty arthritis

13
Q

Titanium in hip prosthesis

A

What is it: after hip translants, titanium seeps from the implant into surrounding tissues

Appearance: macrophages pick up titanium and store it within the dermis of the skin, appears as small dark brown granules

Special stain: none

Birefringent: no

Significant: yes, indicates disintegrstion of prosthetic

14
Q

Haemosidern in liver

A

What is it: RBCs are broken down and haemoglobin is stored as haemosiderin, causing this pigment.

Appearance: groups of blue granules amongst hepatocytes in the liver, but can also appear in macrophages within fibrous scar tissue (looks like large clumps)

Special stain: PBR (haemosiderin is blue)

Significant: yes, indicates haemosiderin