Histopathology

Histopathology is the front page of Pathology, commonly called as Main Lab, which deals with tissues, sent either fresh or fixed , for routine first-step diagnoses.  Different equipments and machines are used to carry out a series of procedures performed by  Biomedical Scientists. The end product can be a routinely stained H&E or a special stained section, as requested by  the Pathologists.

Histopathology Sections

SQUH histopathology has both diagnostic and research histopathology laboratories where histotechnical procedures play a vital role in medicine. 


Sections in Histopathology are:

1)      Reception area:-

Each tissue sent from SQUH operating threatre, wards, OPDs and outside hospitals is received, registered and given a corresponding histopathology accession number.

2)      Grossing area:-

The Pathologist gives a macroscopic description of the specimen and takes representative sections which are placed in appropriate plastic cassettes labelled with the corresponding histopathology accession  number. The tissues are kept fixed in 10% neutral buffered formalin.

3)      Processing area:- In approximately 16 to 18 hours, the properly fixed tissue blocks are passed through a series of steps  and different solutions in the automatic processing machine for dehydration clearing and infiltration with melted paraffin wax.

4)      Blocking out:-

The processed tissues are embedded in suitably sized metal moulds with melted paraffin wax (approx. 600C) and allowed to solidify in the cold plate. 

5)      Microtomy:-

Microtome is a machine specially designed to cut thin paraffin sections.  The paraffin sections are floated in warm water bath and mounted on clear glass slides labelled with corresponding histology number. Slides are allowed to dry in hot plate.

6)      Staining:-

Hematoxylin and Eosin routine staining is done in the automated staining machine .  Special staining techniques are performed by the Biomedical Scientists.  Special stains facilitate in the recognition of various tissue elements by their different colour reactions. 

7)      Mounting the stained slides:-

The stained tissue sections are sealed under a glass cover slip either manually or by using the automatic mounting machine.   

8)     Quality check of sections:-

Before sections are submitted to the Pathologist, these are examined microscopically and checked with their corresponding paraffin blocks. Sections are placed in slide tray with the appropriate request form.

9)  Preservation of slides, blocks and reports:-

Blocks, slides and reports are properly filed in appropriate boxes for future study and research purposes.