Unit 1 - Introduction to Oral Pathology (Lecture) Flashcards
Pathology
The study of the nature of a disease and its causes, development, and consequences
What are the 4 components of disease addressed by pathology?
- Cause/etiology
- Mechanisms of development
- Morphologic changes/structural alteration of cells
- Consequences of changes (lesions/manifestations)
Pathogenesis
Study of the development of disease
Pathophysiology
Study of the changes of normal mechanical, physiological, and biochemical functions, either caused by a disease or resulting from an abnormal syndrome
Oral Pathology
Study of specifically diseases affecting the oral cavity
Lesion
Term used to describe a specific local change in the tissue
Manifestation
Clinical evidence or effects (signs & symptoms of disease)
What are our 3 obligations as DH’s to study oral pathology?
Legal, professional, and ethical
What is the role of the DH in oral pathology?
Identifying, Interpreting, and Reporting
Accurate descriptions of oral lesions must include what 3 things?
Location, distribution, and physical characteristics
Describe a tissue reflectance test
This test includes using a light providing a blue-white illumination and an acetic mouth rinse prior to illumination. Conducted in a dim room.
Describe normal vs. abnormal tissue readings during a tissue reflectance test
Normal tissue appears dark (absorbs light), whereas abnormal tissue appears bright white (reflects light)
Describe normal vs. abnormal tissue readings during a tissue reflectance test
Normal tissue appears dark (absorbs light), whereas abnormal tissue appears bright white (reflects light)
Describe an autofluorescence test
Hand held unit emits a cone of blue light creating different levels of fluorescence
Describe normal vs. abnormal tissue readings during an autofluorescence test
Healthy tissues appear pale green, whereas abnormal tissues appear dark green/black
Describe an autofluorescence spectroscopy
Combines tissue reflectance and autofluorescence using white light; it uses a small probe, making it only useful on small lesions and only those noted on observation. The value of this test is questionable.
What is a toluidine blue stain test?
A valuable preliminary screening tool for oral cancer. The dye is applied topically to suspected site; the dye will define margins for biopsy.
What is the disadvantage/draw back to the use of toluidine blue stain?
Inflammatory cells will also pick up stain.
Describe a positive result for a toluidine blue stain test?
Only dark royal blue staining is positive. Benign lesions have no nuclear staining and appear pale blue.
What does the acronym MIND stand for?
Metabolic, Inflammatory, Neoplasm, Developmental
What are the 3 subcategories and sub-subcategories of a metabolic disease/lesion?
Compromised Organ System
Hormonal
Nutritional
(no sub-sub categories)
What are the 4 subcategories and sub-subcategories of an inflammatory disease/lesion?
Trauma (Physical, Chemical, Thermal)
Reactive (no sub-sub)
Infection (Bacterial, Fungal, Viral)
Immunologic (Endogenous allergen, Exogenous allergen)
What are the 3 subcategories and sub-subcategories of a neoplasm disease/lesion?
Benign (N/A)
Premalignant (N/A)
Malignant (Carcinoma, Sarcoma)
What are the 2 subcategories and sub-subcategories of a developmental disease/lesion/condition?
Genetic
Acquired
What are the 8 categories of diagnosis?
Clinical, Radiographic, Historical, Laboratory, Surgical, Therapeutic, Microscopic, Differential
What type of diagnosis: diagnosis derived from clinical appearance and palpation of the lesion; based on colour, shape, location, and history of the lesion
Clinical
What type of diagnosis: microscopic evaluation of a biopsy specimen taken from the lesion is often the main component of the definitive diagnosis
Microscopic
What type of diagnosis: personal history, family history, past and present medical and dental histories, history of drug ingestion and history of presenting disease or lesion provides information necessary for the definitive diagnosis
Historical
What type of diagnosis: radiograph provides sufficient information to establish the diagnosis
Radiographic
What type of diagnosis: surgical intervention provides conclusive evidence of diagnosis when the lesion is opened
Surgical
What type of diagnosis: prescribing therapeutic drugs and observing the results based on clinical and historical information
Therapeutic
What type of diagnosis: laboratory tests, including blood chemistries and urinalysis, can provide information for a definitive diagnosis
Laboratory
What are the 4 main reasons for biopsy?
- Highly reliable and accurate method
- Provides a microscopic examination (to have greater knowledge of the area)
- Rules out or confirms the malignancy of the area
- Allows for a definitive diagnosis
What is an excision biopsy?
Surgical removal of the entire lesion plus a rum of surrounding normal tissue with a scalpel (safety margin)
What is an incisional biopsy?
Removal of only a small position of the whole lesion plus a small section/rim of surrounding tissue (wedge shape)
What is a needle biopsy?
Needle aspiration; thin needle inserted into the area and material of the lesion is removed
What is a punch biopsy>
Tubular instrument is inserted through to the deeper tissue to cut off tissue at the base; a type of incisional biopsy
A test involving scraping the lesion with a cotton swab, evaluating only superficial cells, making it not ideal.
Exfoliative Smear/Cytology Sample
When a sample has an abnormal result during an exfoliative smear, what is the next step?
A biopsy is mandatory
Brush painlessly collects cells from full thickness (penetrates to basement membrane); positive results should be biopsied
Transepithelial Cytology
Once lesion/portion is removed during oral exfoliate and transepithelial cytology, what happens?
- Specimen is placed in a fixative solution (formalin)
- Specimen is sent to a lab where microscopic slides are prepared for examination
- Examination by cytopathologist leads to definitive diagnosis
