Histopathology 1: Fundamentals of histology

Question 1

List 2 histological features of Squamous cell carcinomas ?

Answer 1

Keratin production
Intracellular bridges

Question 2

List 2 histological features of Adenocarcinoma ?

Answer 2

Gland forming
Mucin production

Question 3

Which part of oesophagus tends to get Squamous cell carcinomas ?

Answer 3

Upper 1/3

Question 4

Which stain identifies haemochromatosis ?

Answer 4

Prussian blue (Pearls stain)

Question 5

List 3 situations in which you see eosinophils ?

Answer 5

• allergic reactions
• parasite infections
• Tumours e.g. Hodgkin’s lymphoma, squamous cell carcinoma, myeloproliferative diseases (characteristically infiltrate tumours)

Question 6

Which cells form granulomas ?

Answer 6

Macrophages

Granuloma = collection of macrophages

Question 7

Name a disease in which you get caseating granulomas ?

Answer 7

TB

Caseating = necrosis in the middle of these granulomas

Question 8

How to notice lymphoma

Answer 8

• CLONAL proliferations- the cells all look the same
  
  • If there are a mix of other cells- plasma cells or neutrophils, then it might be inflammation

Question 9

what causes feline contractions in oesophagus

Answer 9

• eosinophilic oesophagitis - allergy to foods coming down the GIT

Question 10

lots of mast cells in the epidermis is suggestive of…

Answer 10

urticaria

mast cells = large, lots of granules

Question 11

what are macrophages associated with (2)

Answer 11

• late acute inflammation
• chronic inflammation (inc granulomas)

Question 12

when do you know if you have a proper sputum sample

Answer 12

see pigmented macrophages is the sample - shows it has come from the alveoli

Question 13

list 5 causes of granulomas

Answer 13

TB
leprosy
cat scratch fever
fungal infections
sarcoidosis

Question 14

what are carcinomas and name 3 types

Answer 14

malignant tumours of EPITHELIAL CELLS

• Squamous cell carcinomas - keratin + IC bridges (+ swirls of keratin)
• Adenocarcinoma - mucin (stains) and glands
• Transitional cell carcinomas: arise from transitional epithelium

Question 15

list sites of SCC (6)

Answer 15

skin
head+ neck
oesophagus
anus
cervix
vagina

Question 16

sites of origin of adenocarcinoma (5)

Answer 16

Basically sites with glandular epithelium:

• lung
• breast
• stomach
• colon
• pancreas

Question 17

what stain is used for melanin

Answer 17

fontana

Question 18

histochemical vs immunohistochemical stain

Answer 18

histo - reaction between stain and tissue (H+E)
immuno - using antibodies against specific antigens

Question 19

Stain used for amyloid

Answer 19

congo red

• look under polarised light
• produces apple-green birefringence
• suggests amyloidosis

Question 20

when would you use cytokeratin stain

Answer 20

• this is a type of Immunohistochemical stain (uses antibodies to stain)
• all epithelial cells produce cytokeratins, so can use cytokeratin subtypes stains to distinguish what type of cancer a patient could have if metastasised

Question 21

what is CD45 used to mark

Answer 21

lymphoid cells

Question 22

What are transitional cell carcinomas?

What is the main sites?

Answer 22

Tumours which arise from transitional epithelium

Main site = urinary system (pelvis of kidneys, ureters, bladder etc.) - transitional cells have ability to stretch (useful when bladder fills)

Question 23

Key immunological lymphoid marker (CD…)

Answer 23

CD45

Question 24

Immunofluorescence vs Immunoperoxidase as Immunohistochemical stains

Answer 24

• Immunofluorescence: antibody binds specifically to antigen, another anitbody will then bind to the antibody-antigen complex and this antibody will have a fluorescent tag
• Immunoperoxidase: antibody is added to the tissue which binds to a particular antigen, enzyme is then added which binds to the antibody substrate is then added which produces a product of a certain colour

Question 25

What are sarcomas?

Answer 25

malignant tumours of mesenchymal cells e.g. connective tissue (muscle, bone, cartilage)

Question 26

Osteoma vs osteosarcoma

Answer 26

• Osteoma- benign tissue of bone
• Osteosarcoma- malignant tissue of bone

Question 27

What is Granulomatous inflammation and give 2 examples

Answer 27

• a subset of chronic inflammation
• 2 examples: TB and sarcoid

Question 28

What do mast cells look like?

Answer 28

Large cells containing lots of granules with range of inflammatory mediators

Question 29

What do eosinophils look like?

Answer 29

• Have red granules
• Bi-lobed nuclei

Question 30

Lymphocytes and Plasma cells are key markers of what?

Answer 30

Key inflammatory cells of CHRONIC inflammation