Gross Techniques In Surgical Pathology. Introduction. The routine work associated with a surgical pathology specimen includes gross & microscopic examinations. Gross examinations give an idea about size ,shape of specimen &any gross abnormality like ulceration, nodularity.
The routine work associated with a surgical pathology specimen includes gross & microscopic examinations.
Gross examinations give an idea about size ,shape of specimen &any gross abnormality like ulceration, nodularity.
The dissection, gross description &selection of sections for microscopic study is a crucial part of pathologic examinations
1- paraffin embedding method ( the routine & widely used procedure).
2- frozen section (intra-operative).
3- cytological diagnosis (exfoliative & fine needle aspiration cytology.
4- digital pathology & telepathology.
Include the following principle steps:
1- fixation:- to preserve the tissue, fixatives include formaldehyde, Zenker’s solution, picric acid, Bouin’s solution,
The best fixative is 10% buffered formalin
2- always available.
3- good penetration into tissue.
4- cause little shrinkage.
5- preserve RBCs & fatty tissue.
6- special stains can be used on tissues fixed with it.
7- preserve color of the tissue.
8- good hardening.
1- if tissue preserved in formalin for long time, formic acid will be formed which affect stainability of tissue with different stains, so it should be changed every 3-6 months.
2- when formalin solution is stored for long period a white precipitate of para formaldehyde which will not affect the efficiency of formalin as a fixative & can be removed by alcohol.
3- cannot preserve glycogen.
3- Clearing:- by using xyline.
4- Paraffin impregnation.
6- Sectioning:- by using a microtome, the tissue is sliced into very thin sections ranging from 4-6 micrometer in thickness.
7- Attaching sections to the slides.
9- Staining:- the standard staining method is H & E which stain the nucleus blue (basophilic) & the cytoplasm pink-red (acidophilic).
10- Mounting:- by using DPX &cover slip.
1- Special stains like PAS (periodic acid schiff) stain, Gram, Giemsa, Ziel-Neelson.
2- Enzyme histochemistry.
3- Tissue culturing.
5- X-ray microanalysis.
6- Electron microscopy.
7- Immunohistochemistry, sensitive &specific.
8- Flow cytometry.
10- Polymerase Chain Reaction (PCR).