Fundamentals of Histology

Question 1

Name the cells and what they are associated with.

Answer 1

Neutrophils - Acute inflammation

Question 2

Name the cells and what they are associated with.

Answer 2

Lymphocytes and plasma cells - Chronic inflammation (lymphomas)

Question 3

Name the cells and what they are associated with.

Answer 3

Eosinophils

• Allergic reactions
• Parasitic infection
• Tumours (i.e. Hodgkin’s disease) - more as a reaction to tumours
• Eosinophilic oesophagitis (allergic reaction)

Question 4

Name the cells and what they are associated with.

Answer 4

Mast cells (large and full of inflammatory granules)

Welts and rashes (i.e. urticaria)

Question 5

Name the cells and what they are associated with.

Answer 5

Macrophages

• Late acute inflammation
• Chronic inflammation (inc. granulomas [organised collection of activated macrophages]
• Ziehl-Neelson stain (an acid-fast stain to differentiate sarcoid and TB)

Question 6

Name the types of tumours

Answer 6

• Carcinomas
• Sarcoma
• Lymphoma
• Melanoma

Question 7

Name the types of carcinomas

Answer 7

• Squamous cell carcinomas / SCC – keratin production, intercellular bridges 
• Adenocarcinomas – mucin production, glands
• Transitional cell carcinomas – ‘just looks like transitional epithelium’

Question 8

Describe the histopathology, origin and staining used for SCCs

Answer 8

Squamous cell carcinomas / SCC – keratin production, intercellular bridges –>

• Origins – skin, head/neck, oesophagus, anus, cervix, vagina
• P40 stain for SCC of lung

Question 9

Describe the histopathology, origin and staining used for adenocarcinomas

Answer 9

• Adenocarcinomas – mucin production, glands
  
  • Origins – lung, breast, stomach, colon, pancreas, etc.
  • Mucin stain to differentiate from SCC (which has no mucin production)
  • Fontana stain for melanin
  • TTF-1 stain for adenocarcinoma of lung

Question 10

What is this and in which type of tumour would it be found?

Answer 10

Intracellular bridges - SCC

Question 11

Name the types of stains

Answer 11

• Cytological stains
  
  • General stain = Papanicolaou
• Histochemical
• Immunohistochemical

Question 12

How do (histo)chemical stains work?

Answer 12

• Histochemical (or ‘chemical’) – e.g. H&E (Haematoxylin and Eosin)
  
  • Based on reaction between stain and component of tissue
  • Reaction creates specific colour to be identified
• I.E. Copper = Rhodanine stain
• I.E. Haemochromatosis = Prussian Blue Iron Stain
• I.E. Amyloid = Congo Red Stain  Apple Green birefringence
• I.E. Brucellosis = Castaneda medium
• I.E. A1AT, Candida = Periodic Acid Schiff stain

Question 13

How do immunihistochemical stains work?

Answer 13

• Immunohistochemical:
  
  • Based on antibodies matching to specific antigens on tissue
  • Need detection system to make binding visible
• I.E. Lymphoid marker = CD45
• I.E. Epithelial cell marker = cytokeratins
• I.E. Neuroendocrine marker = chromogranin stain
  
  • MEN 1, insulinomas
  • Phaeochromocytoma

Question 14

How does imunoflorescence work?

Answer 14

Question 15

How does immunoperoxidase work?

Answer 15