Oral Pathology Flashcards
What types of specimen are sent for histopathological investigation?
Biopsy - Incisional
Biopsy - Excisional
Resection
What is a fixed specimen preserved in?
10% neutral buffered formalin
How is a fresh specimen preserved?
Frozen
What is the process once a specimen is received at pathology?
- Logged in and assigned unique pathology number
- Macroscopic description and cut-up by pathology (photos & decalcification)
- All biopsy/appropriate blocks taken from resection specimen and placed in cassettes
- Processing - fixation then dehydration of tissue in alcohols
- Embedding - hot paraffin wax to form tissue blocks
- Microtome used to cut sections - 4um thickness
- Sections floated in waterbath, mounted on slide, stained and coverslip placed
- Slides examined
What stains are used routinely?
Haematoxylin and Eosin (H&E)
What other investigations may be used in addition to light microscopy?
Immunofluorescence
In situ hybridization
Electron microscopy
Cytogenetic and molecular genetic analysis
What is hyperplasia?
the abnormal multiplication or increase in the number of normal cells in normal arrangement in a tissue
What is hypertrophy?
the enlargement or overgrowth of an organ or part due to an increase in size of its constituent cells
What is atrophy?
a decrease in cell size by loss of cell substance
What is metaplasia?
reversible change in which one adult cell type is replaced by another adult cell type
What is hyperkeratosis?
thickening of the stratum corneum
What is orthokeratosis?
the formation of an anuclear keratin layer, as in normal keratinised stratified squamous epithelium
What is parakeratosis?
the persistence of nuclei in the cells of a keratin layer
What is dyskeratosis?
premature keratinization of epithelial cells that have not reached the keratinizing surface layer
What is acanthosis?
increased thickness of prickle cell layer
What is acantholysis?
the loss of intercellular adhesion between keratinocytes
What is epithelial dysplasia?
alteration in differentiation, maturation and architecture of adult epithelial cells
What is ulceration?
mucosal/skin defect with complete loss of surface epithelium
What is apoptosis?
programmed cell death
What is necrosis?
cell death by injury or disease
What are developmental white lesion?
Fordyce granules
What are hereditary white lesions?
White sponge naevus
Pachyonychia congenita
Dyskeratosis congenita
What are normal white lesions?
leukodema
What ate traumatic white lesions?
Mechanical/frictional
Chemical
Thermal