Diagnosis of Neoplasia Flashcards
How to diagnose a Neoplasm
Physical examination and diagnostic imaging are INSUFFICIENT
Cytopathological (cells) and histopathological (tissue) examination are important
Biopsy
Extraction/sample of cells or tissues for examination to determine the presence or extent of neoplasia
Tissue can be examined under microscpe and analysed chemically
Includes:
○ Fine Needle Aspiration (FNA) biopsies (cytopathology)
○ Surgical tissue biopsies (histopathology)
Fine Needle Sampling Pros and Cons
Good place to start
* Easily accessible for external masses
* Cost effective
* Relatively low risk technique
* Important information obtained
* Insufficient - Histopathological examination is also necessary
Surgical Tissue Biopsy Pros and Cons
Doesn’t just provide diagnosis
Impact patient’s prognosis and ultimately directs the therapeutic plan
Information obtainable:
○ Grading - useful for prognosis
○ Margin evaluation - useful for planning future treatments
○ Architecture of tissue
Can be done:
○ Pre-operatively - when results can change treatment or prognosis
○ Post-operatively - after surgical removal
Importance of Histopathology
Microscopic Description (Tissue Architecture)
○ Cytological features
Junctional change for melanoma
Osteoid for osteosarcoma
○ Degree of invasion
Adjacent tissue
Vasculature
○ Necrosis
○ Mitotic count
Absolute number of mitoses counted in a specified number of fields or in a specified area
Referred to HPF (high power field)
Tumour Grade
○ Predicts biological behaviour
○ Based upon published grading criteria
Importance of Tissue Biopsy
Surgical Margins
Important parameter for surgeons
Microscopic evaluation of margins:
○ Description of the neoplastic cells closest to the margin
Lateral
Deep
Tumour bed
○ Distance from the tissue edge to the closest neoplastic cell
○ Tissue constituents and tissue quality of the margins
Excisional Biopsy
Entire mass removed
Incisional Biopsy
Small fragments removed
