Fundamentals of histology Flashcards
Which cells are associated with chronic inflammation?
Lymphocytes and plasma cells. (Lymphomas)
Top= lymphocytes due to infection
Bottom= lymphocytes due to lymphoma
What are eosinophils associated with?
Allergic reactions- drugs[esp seen in liver], asthma, rhinitis etc.
Parasitic infections.
Tumours, e.g. Hodgkin’s disease.- inflammatory response to other tumours + [rarely] eosinophil tumour
What are macrophages associated with?
Late acute inflammation AND
Priming chronic inflammation (including granulomas).
Produce granulomas
List some different types of tumours.
Carcinoma
Sarcoma
Lymphoma
Melanoma
What are the different types of carcinoma and their characteristic features?
- Squamous cell carcinomas: keratin production, intercellular bridges.
- Adenocarcinomas: mucin production, glands (transitional cell carcinomas).
What are the main sites of origin of squamous cancers?
Skin
Head and neck
Oesophagus
Anus
Cervix
Vagina
Lung [although no squamous epithelium in lung, smoking causes metaplasia, creating squamous cells]
What are the main sites of origin of adenocarcinomas?
Lung
Breast
Stomach
Pancreas
Colon
Prostate
What is a (histo)chemical stain?
Common histochemical stains?
Chemical reaction between the stain and a specific component of the tissue.
Results in specific colour or other property which can be identified.
Examples:
Congo red stain= amyloid + apple green birefringence
Ziehl Neelson= TB
Prussian blue iron stain= Haemochromatosis
What is an immunohistochemical stain?
Based on using an antibody specific to an antigen in the tissue.
Need a detection system to make this binding visible. e.g. immunofluorescence [second antibody attached to fluorescent protein], immunoperoxidase.
What cells are associated with acute inflammation?
Neutrophils
What does this show?
Appendix
Acute appendicitis
Lots of polymorphs
Signs of lymphoma
Multiple dense monomorphic lymphocytes
What is the characteristic inflammatory cell of asthma?
Eosinophil
What are mast cells associated with?
Allergic reaction
What is a granuloma?
Organised collection of activated macrophages
Macrophages become predominantly secretory [now look epithelioid, instead of phagocytosing
Sometimes contain giant cells- due to fusion of macrophages
Causes: Many- TB [Ziehl Nielsen], Sarcoidosis etc.
What does this show?
Malignant melanoma
Pigmented cells
What can be used to detect haemochromatosis in liver?
Prussian blue iron stain
Brown pigment will turn blue
What does normal glandular tissue look like?
What is used to detect amyloid?
Congo red stain
Under polarised light: red-> apple green
Apple green birefrigence
What stain is used for TB?
Ziehl Neelson
How can you identify type of cancer from history?
Carcinoma vs lymphoma
Which is primary tumour?
Carcinoma vs lymphoma
Stain for epithelium: Cytokeratin
Stain for leukocytes: CD45
Positive result is brown for both stains
Which is primary tumour?
Different stains for different types of epithelium
eg. CK20+ = colon cancer
How to identify cause of ulcer?
Multinucleate cells indicate herpes- how to find which herpes virus?
Immunohistochemical stain - antibody towards herpes viruses
Eg, in this case, herpes simplex showed up positive
