Histopathology 1: Fundamentals of histology Flashcards
List 2 histological features of Squamous cell carcinomas ?
Keratin production
Intracellular bridges
List 2 histological features of Adenocarcinoma ?
Gland forming
Mucin production
Which part of oesophagus tends to get Squamous cell carcinomas ?
Upper 1/3
Which stain identifies haemochromatosis ?
Prussian blue (Pearls stain)
List 3 situations in which you see eosinophils ?
- allergic reactions
- parasite infections
- Tumours e.g. Hodgkin’s lymphoma, squamous cell carcinoma, myeloproliferative diseases (characteristically infiltrate tumours)
Which cells form granulomas ?
Macrophages
Granuloma = collection of macrophages
Name a disease in which you get caseating granulomas ?
TB
Caseating = necrosis in the middle of these granulomas
How to notice lymphoma
- 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
what causes feline contractions in oesophagus
- eosinophilic oesophagitis - allergy to foods coming down the GIT
lots of mast cells in the epidermis is suggestive of…
urticaria
mast cells = large, lots of granules
what are macrophages associated with (2)
- late acute inflammation
- chronic inflammation (inc granulomas)
when do you know if you have a proper sputum sample
see pigmented macrophages is the sample - shows it has come from the alveoli
list 5 causes of granulomas
TB
leprosy
cat scratch fever
fungal infections
sarcoidosis
what are carcinomas and name 3 types
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
list sites of SCC (6)
skin
head+ neck
oesophagus
anus
cervix
vagina
sites of origin of adenocarcinoma (5)
Basically sites with glandular epithelium:
- lung
- breast
- stomach
- colon
- pancreas
what stain is used for melanin
fontana
histochemical vs immunohistochemical stain
histo - reaction between stain and tissue (H+E)
immuno - using antibodies against specific antigens
Stain used for amyloid
congo red
- look under polarised light
- produces apple-green birefringence
- suggests amyloidosis
when would you use cytokeratin stain
- 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
what is CD45 used to mark
lymphoid cells
What are transitional cell carcinomas?
What is the main sites?
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)
Key immunological lymphoid marker (CD…)
CD45
Immunofluorescence vs Immunoperoxidase as Immunohistochemical stains
- 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
What are sarcomas?
malignant tumours of mesenchymal cells e.g. connective tissue (muscle, bone, cartilage)
Osteoma vs osteosarcoma
- Osteoma- benign tissue of bone
- Osteosarcoma- malignant tissue of bone
What is Granulomatous inflammation and give 2 examples
- a subset of chronic inflammation
- 2 examples: TB and sarcoid
What do mast cells look like?
Large cells containing lots of granules with range of inflammatory mediators
What do eosinophils look like?
- Have red granules
- Bi-lobed nuclei
Lymphocytes and Plasma cells are key markers of what?
Key inflammatory cells of CHRONIC inflammation
