Histopath 1: Fundemental of Histo Flashcards
What are neutrophils present in and what do they look like?
Acute inflammation (sterile or non-sterile e.g. appendicitis)
Multilobed (purple) and granulated (pink)
What are macrophages present in and what do they look like?
Late acute inflammation (clear debris), usually phagocytic
Chronic inflammation becomes more secretory -> large cells with lots of cytoplasm
What are lymphocytes present in and what do they look like? what does it look like in lymphoma?
Chronic inflammation (light purple)
Lymphoma = sheets of lymphocytes (clonal = look the same)
What are plasma cells present in?
Chronic inflammation, myeloma
What are eosinophils present in and what do they look like?
Allergic reactions
Parasitic infections
Tumours e.g. Hodgkin’s disease, SCC, MPD
Bi-lobed nuclei (blue) with red granules
What are mast cells present in and what do they look like?
Allergic reactions
Large cells containing lots of granules
Range of inflammatory mediators
What are carcinomas?
Malignancy of epithelial cells
What are sarcomas?
Tumours of mesenchymal cells (connect tissue eg muscle bone cartilage)
What are the 3 main types of carcinomas?
SCC
Adenocarcinoma
Transitional cell carcinomas
What are the histological features of SCCs?
Keratin production
Intercellular bridges (appears as little prickles on edge of cells)
Do NOT form glands
Where do SCCs occur?
Skin, head, and neck
Oesophagus (upper and middle 1/3)
Anus, Cervix, Vagina
What are the histological features of adenocarcinomas?
From glandular epithelium
Forms glands that can secrete substances (e.g. mucin)
What are the different locations of adenocarcinomas?
Lung
Breast
Stomach
Colon
Pancreas
What are the histological features of transitional cell carcinomas?
Epithelium can stretch
Where can transitional cell carcinomas occur?
Kidney pelvis, ureters, bladder
What is the fontana stain used for + what is the result?
+ve for melanin
What is the congo red stain used for + what is the result?
+ve for Amyloid (Apple green birefringence)
What is the prussain blue stain used for + what is the result?
+ve for iron (haemochromatosis)
What is the Hemotoxylin and esoin (H&E) stain used for + what is the result?
H: stains basic parts purple/blue
E: acidic parts red/pink
What are immunohistochemical stains? What are the different types?
involves antibodies directed against a specific antigen which then detect antibody-antigen complexes
Immunofloresence
Immunoperoxidase
How does immunofloresence work?
Ab binds to Ag; (if this is fluorescently tagged - direct)
need fluorescently tagged Ab to bind to Ab-Ag complex (indirect)
How does immunoperoxidase work?
Ab binds to Ag in tissue -> add enzyme to Ab -> substrate added -> product has a specific colour change
What is the difference between a histochemical stain and an immunohistochemical stain?
Histochemical stain – based on the chemical reaction between the stain and the tissue. The product will have a specific colour or other property that can be identified
Immunohistochemical – involves using antibodies to detect a specific antigen within the tumour
What cytological feature is suggestive of a good sputum sample?
Pigmented macrophages – this suggests that they have come from the alveoli
Define granuloma
Organised collection of activated macrophages
What do macrophages in granulomas fuse together to form?
Langerhans giant cells
What is a key immunological lymphoid marker?
CD45
What is a classic histological feature of HSV infection?
Cells with multiple nuclei
Which WBC is prevalent in parasitic infections?
Eosinophils
Which tumour type produces keratin and intercellular bridges?
SCC
Which stain is used for iron?
Prussian Blue
