L1 : introduction to the unit Flashcards
pathology definition
the science of the cause and effects of disease (but acts as a synonym for the disease itself)
what are examples for potential tests that can be requested for
- immunohistochemistry test
- immunofluorescence test
- genetic test ( available in most NHS labs and part of the general treatment plan)
how did medical students learn about normal anatomy
with anatomical models (wax, wood), dissections, post mortems and anatomical theatres where you can have a corpse preserved in formalin
what is a teratoma
a tumour composed of different types of tissue not normally present at the site e.g. hair, muscle, bone or teeth (it is multipotent and can show cells deriving from different lineages)
how many lines of cell differentition are there in an embryo
3
what are the 3 lines of differentition in an embryo
- endodermal
- ectodermal
- mesodermal
what is the endodermal layer
The inner layer that forms the linings of the digestive and respiratory systems, as well as organs like the liver and pancreas.
what is the ectodermal layer
The outer layer that gives rise to the skin, hair, mammary glands, and part of the nervous system.
what is the mesodermal layer
The middle layer that forms muscle, cartilage, bone, the heart and circulatory system, gonads, and the urogenital system.
where are teratomas most commonly found in men and women
in the ovaries in women (usually benign) and in testicles for men (rarer and even if it looks mature it can be aggressive)
what are possible causes of disease
- tumours
- metabolic imbalances
- infection
- Genetic predisposition ( somatic or germline)
- Environmental factors
(usually diseases are caused by many factors interconnected (although it can be caused by one) which is why individuals exposed to the same risk factor can have different outcomes)
What are some examples of specialty teams
- Gastrointestinal Pathology
- Pulmonary Pathology
- Dermatopathology
- Breast pathology
- Gynaecopathology
- Head and neck pathology
- Hematopathology
- Uropathology
- Nephrology
- Soft tissue pathology
- Orthopaedic pathology
- Endocrine pathology
- Paediatric and perinatal pathology
what samples are assessed in a cell pathology lab
- core biopsy for superficial (not epidermal) or deep lesions. The biopsy can be guided by ultrasound or CT imaging
- Organs
- Soft tissue
- Bone and marrow
what now happens for most cytological samples
The cell samples are taken and put in formalin, fixed, and put in blocks with paraffin
pros and cons of using formalin and paraffin for cytological samples vs smearing and staining
Pros :
more accurate, rapid and being in paraffin you can cut through the sample so you can repeat the tests
cons:
more labour intensive, expensive and time consuming
when are punch vs core biopsies taken
punch
when a small biopsy is required e.g. for eczema you take a small sample of the skin, (small and superficial that doesn’t generally go deeper than the dermis / epidermis)
Core
involves collecting a much larger tissue sample, typically when the sample goes much deeper. this involves using a biopsy needle that goes through the mass to collect the sample e.g. bone or breast and get a representative image of what you have
what are some implications of having a biopsy taken
the margin around the area might be compromised (want to make sure you don’t compromise treatment options later on). There is also a chance that you can seed malignant seeds along the track so to prevent this you mark the area of the biopsy and go beyond this point.
what does the processing of bone biopsies usually involve and what is the issue with this
typically involves decalcification. this could cause damage and affect the immunochemistry or genetics (therefore need to be thorough and careful with how the decalcification process is carried out)
example biopsies for superficial, epidermal or dermal lesions
punch biopsy and shaving
example biopsies for deep and superficial lesions
incisional biopsy and excisional biopsy
what are endoscopic biopsies and where are they carried out
a procedure that involves using a long, thin tube called an endoscope to obtain tissue samples from inside the body. It is carried out in the gastrointestinal tract, large bowel, abdomen, bladder, oral cavity …..
what is a resection specimen
tissue sample or organ removed during a surgical resection procedure
how is looking at a resection specimen useful
just by looking at the specimen you can have an idea of what is happening e.g. polyps, skin lesion or pigmentation, odd profiling …. without knowing the full case you can be informed.
