Histopatology!

Fig1.1 Hotplate.
Added to explain in my reply to one of the comments.


Subject: Histology

I am posted to Histopathology/Cytology department, together with Ernest and Tira. ;) (Hope they can stand my craziness at times as the formalin is making us real high. LOl)
This week we are at the Histopathology department, and I heard that we will be in cytology for a month! We been there before, during our tour and I saw the Biosafety Hood (remember what Ms. Chew mentioned before? Yes. The expensive one. )
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The overview of the Histopathology was explained to us by one of our friendly colleagues.
Surgeon cuts specimen of interest-->sends to Histopathology department receiving room-->request forms are checked thoroughly and biopsy no is issued to each patient/case-->sends specimen to trimming room(2 steps away only. Haha)-->pathologists trim big/large specimen while medical technologists trims smaller ones-->cut specimen placed in cassettes--> send for tissue processing--> embedding-->microtomy-->heat slides before staining (H&E as the most common staining)-->sorting slides according to the different doctors and the request forms--> send out for pathologists to read the slides

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Assisting during trimming:
These few days, we were allowed to observe how our colleagues and help out what we could. I assisted the pathologist during trimmer by preparing and labeling cassettes (using a special tissue and cassette marker which cannot be dissolved by any solvent known to the histo-department) for them according to the specimen received and jot down the number of cassettes used for each case before putting them into formalin. The most common specimens received are breast, uterus, colon and kidney and the others are lungs, bile, prostate, fetus, and placenta. I even found out from our colleagues that they had received eyeball and an entire leg before! During trimming, the pathologist will also dictate what they observed, for instance, a cyst in found __ cm near the right margin. These dictations will be sent to the admin staff who will type it out as a report to be attached to the respective request form. Sometimes, the pathologists will also ‘colour’ the specimen using special dyes of different colours as to denote the different parts of the specimen.

Fishing:
Other than assisting during trimming, we also did fishing, heating of slides and sorting slides. After cutting the tissues using the microtomy, we will put the tissues into cold water first before putting them into the water bath. This is to increase the surface tension of the tissues, so that there will be no folds on the tissues which can hinder reading of slides. The water bath has an alarm system so that once the temperature is above 550C, the alarm will beep. The optimum temperature is between 500C to 540C. We will fish the tissues before labeling them according to what is stated on the cassettes. Everyday, we will fish from around 8am to 10 plus am, depending on the workload. Tissues are to be fished in the middle of the slide with the same orientation as the specimen embedded in the paraffin wax. If tissues are fished too high on the slide, it may be properly stained by the auto-stainer (machine for staining). If too low, tissue may be damaged during heating when not properly handled. The correct orientation facilitates checking of slides with cassettes before sending them out to the doctors and pathologists. Smaller tissues (app. 1cm by 1cm) are fished 6 in a slide, 2 by 2 by 2 slices, while normal size tissues are 1 per slide.

Heating:
After fishing, the slides will be tap dry before placing them slanted(partially) on the hot plate to remove all the water on the slide first. This is to prevent ‘smearing’ or moving of tissues out of their positions (on the slide) when they are heated on the hot plate for 3 mins at the highest temperature on the machine (the knob is pointing at 10, the maximum).

Staining:
After heating the slides, we will load the slides for H&E staining into this awesome machine called an auto-stainer. There is a total of 18 buckets of reagents, with 0.5% acid alcohol and lithium carbonate (not for H&E but for other types of staining). This machine also incorporates a part where it mounts the coverslip for you! So fast and with no air bubbles in it! Not like that time where our fingers trembled when placing coverslip. Some slides are requested for special staining like GMS and PAS where they will be placed in another machine. Some types of staining even need up to 1.5 hours!

Sorting:
After the slides are mounted, we will sort them according to their batch no and biopsy no before sorting them again according to respective request forms and the different doctors. These will be checked by our colleagues before sending them out.

The manpower in histopathology department is rotated throughout the different sections, for instance, receiving, trimming, embedding, microtomy, and staining. The hospital we are in receives the most no of specimens and requests everyday, which explains the large no of slides we do everyday. The staff there are also very experience, many of whom with at least 8 years of experience in histopathology department!

Posted by:
Ting Ying Chee =D
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