Biopsy

BIOPSY

Definition

  • Biopsy means examination of a tissue specimen taken from a living animal.

Objectives

  • To identify cells in inflammatory condition
  • To diagnose neoplasm
  • To carryout biochemical and clinical investigations of parenchymatous organs

Methods

The most commonly used methods for tissue procurement are

  • Fine needle aspiration biopsy
  • Punch biopsy
  • Incisional biopsy
  • Excisional biopsy

Fine needle aspiration biopsy

  • Procedure
    • A dry needle attached tightly to the syringe is inserted into the surface lesion (Tumour mass). The cellular mass and tissue fluids are aspirated and smears are prepared immediately on glass slide.
  • Precaution
    • Both syringe and needle should be absolutely dry, since a small quantity of fluid may cause cellular distortion and artefacts.
  • Application
    • To evaluate inflammation, hyperplasia and primary or metastatic tumour cells
    • To diagnose theileriosis (Koch’s blue bodies can be seen by Leishman’s staining).

Punch biopsy

A core of tissue is procured by punching with a special needle.

  • Application
    • Most commonly used for externally palpable mass
  • Instrument needed
    • Tru cut needle / Franklin modified Vim- Silver-Mann needle

Incisional biopsy

  • Principle
    • A small portion of a lesion is surgically removed.
  • Application
    • Preferred method for ulcerated and necrotic lesions and skin lesions.

Excisional biopsy

  • Method
    • Removal of a relatively large specimen of tissues
  • Advantages
    • Both treatment and diagnosis are incorporated.
    • This method permits examination by conventional cytological and histological methods.
  • Application
    • Excisional biopsy is useful in case of skin lesions and tumours

Processing of specimen

  • Blot the specimen to remove excess blood
  • Make impression smears for cytologic examination
  • Submit a portion of tissue for cultural examination
  • Spread gently the other portion on a piece of blotting paper to flatten and
  • orient the tissue for histopathologic examination
  • Place the tissue with the paper in 10% neutral formalin
  • Process the tissue routinely for paraffin embedding
  • Cut sections of 5µ thickness and stain with haematoxylin and eosin (H&E)
Last modified: Saturday, 24 March 2012, 6:55 AM