HistoPath - Fundamentals

Question 1

What is the appearance of neutrophils and what are they associated with

Answer 1

Multi-lobular (purple) cells with lots of granules (pink)

Acute inflammation e.g. appendicits

Question 2

What is the appearance of Lymphocytes and what are they associated with

Answer 2

Large cells, light purple

Chronic inflammation or lymphomas (sheets of lymphocytes)

Question 3

What is the appearance of eosinophils and what are they associated with

Answer 3

Bi-lobed nucleus (blue) with red granules

Allergic reactions
Parasitic infection
Tumours e.g. Hodgkin’s, myeloproliferative

Question 4

What is the appearance of mast cells and what are they associated with

Answer 4

Large with granules

Immune reactions e.g. urticaria
Allergy
Found in connective tissue, with granules of histamine and heparin

Question 5

What is the appearance of macrophages and what are they associated with

Answer 5

Large cells with lots of cytoplasm

Late acute inflammation
Chronic inflammation e.g. granuloma: TB | sarcoidosis | fungal infections

Question 6

What are the main types of tumour

Answer 6

Carcinoma
Sarcoma
Lymphoma
Melanoma

Question 7

What are the features of squamous cell carcinomas

Answer 7

Keratin production (not always)
Intercellular bridges

Question 8

Where may squamous cell carcinomas be found

Answer 8

Skin
Head and neck
Oesophagus
Anus
Cervix
Vagina

Question 9

What are the features of adenocarcinomas

Answer 9

Mucin production
Glands

Question 10

Where can adenocarcinomas be found

Answer 10

Lung
Breast
Stomach
Colon
Pancreas

Question 11

What are the two types of stain

Answer 11

Histochemical or immunohistochemical

Question 12

How do histochemical stains work

Answer 12

Based on the chemical reaction between the stain and a specific component of the tissue
The product of this reaction has a specific colour or other property that can be identified

Question 13

How are histochemical stains used in liver disease and amyloidosis

Answer 13

Cirrhosis → Prussian Blue stain → blue pigment stains iron

Amyloidosis in the glomerulus → congo red positive → place under polarised light → Apple green birefringence

Question 14

How do immunohistochemical stains work and what are the two types

Answer 14

Based on using antibodies specific to an antigen in the tissue
Needs a detection system to make this binding visible

Immunofluorescence and immunoperoxidase

Question 15

What are the following markers of: cytokeratin, CD45, CK20, CK7

Answer 15

Cytokeratin: epithelial marker
CD45: Lymphoid marker
CK20: primary bowel cancer
CK7: primary bowel cancer

Question 16

What stains are used for the following: melanin, amyloid, iron, cells components

Answer 16

Melaning: Fontana
Amyloid: Congo red
Iron: Prussian blue
Nucleus: Haemtoxylin (purple/blue)
Cytoplasm: Eosin (red/pink)

Question 17

What is the difference between immunofluorescence and immunoperoxidase

Answer 17

Immunofluorescence: Ab binds to Ag; need fluorescently tagged Ab to bind to Ab-Ag complex

Immunoperoxidase: Ab binds to Ag in tissue → add enzyme to Ab → substrate added → product has a specific colour change

Question 18

What are the features of Transitional cell carcinomas and where can you find them

Answer 18

Epithelium can stretch

Found in the kidney, pelvis, ureters, bladder