ORAL PATH intro Flashcards
what types of specimens are sent out for histopathological investigation?
diagnostic
resected
what are the 2 types of biopsy?
incisional
excisional
what is an incisional biopsy?
small piece of tissue taken from an area to obtain a diagnosis
what is an excisional biospy?
whole specimen removed for diagnosis and treatment in some cases
what is a resection?
usually after an incisional biopsy, whole specimen removed
how are specimens usually transported through the pathology lab?
fixed - in a 10% neutral buffered formalin
why are specimens placed in formalin?
to prevent tissue breaking down and to cross link the proteins to preserve the histology
why may a fresh specimen be sent to the lab and how is it transported?
frozen
when pt still in theatre and urgent diagnosis is required
also applies to some specimens which require further investigation i.e., immunofluorescent studies
what is a specimen always accompanied by?
correctly filled out pathology request form
once transferred to the lab, what does the pathologist do to the specimen?
pathologist describes what specimen looks like and detail any irregularities
if it is a large biopsy, it will be inked in different colours and dissected
what does a specimen require if it contains bone/ teeth?
decalcification, it must be soft enough to be cut with a scalpel
where are biopsies/ resection specimens placed after descritpion?
in cassettes and given a unique pathology number
what does processing a specimen involve?
further fixation then dehydration of tissue in ethanol
what does embedding a specimen involve?
placing in hot paraffin wax to form tissue blocks
what is used to cut sections from a tissue block and at what thickness?
microtome
4um
after the tissue block is cut, what happens to the sections (4 stages)?
floated in water bath, mounted on glass slide, stained and coverslip placed
in what form is a specimen examined by a pathologist?
in a slide
what are the histopathological layers of the tongue?
epithelium
inflammation
muscle
what are the 3 stains for specimen slides?
hematoxylin and eosin (H+E)
special histochemical stains
immunohistochemistry (antibodies)
in addition to light microscopy with routine and special stains and immunohistochemistry, what other investigations may be used to aid diagnosis?
immunofluorescence
in situ hybridisation
electron microscopy
cytogenetic and molecular genetic analysis
explain digital pathology?
all stages are the same up until the glass slides are produced then these are captured with scanning device to provide a high resolution image that can be viewed on a computer or mobile device
define hyperplasia
abnormal multiplication or increase in number of normal cells in normal arrangement in a tissue
define hypertrophy
enlargement or overgrowth of an organ or part due to an increase in size of its constituent cells
define atrophy
decrease in cell size by loss of cell substance
define metaplasia
reversible change in which one adult cell type is replaced by another adult cell type
define hyperkeratosis
thickening of the stratum corneum
define orthokeratosis
formation of an anuclear keratin layer, as in normal keratinised stratified squamous epithelium
define parakeratosis
the persistence of nuclei in the cells of a keratin layer
define dyskeratosis
premature keratinisation of epithelial cells that have not reached the keratinising surface layer
define acanthosis
increased thickness of prickle cell layer
define acantholysis
the loss of intercellular adhesion between keratinocytes
define epithelial dysplasia
alteration in differentiation, maturation, and architecture of adult epithelial cells
define ulceration
mucosal/ skin defect with complete loss of surface epithelium
define apoptosis
programmed cells death
define necrosis
cell death by injury or disease
