A 12 mm thick slice of liver is processed overnight in one cassette. Its sections show a well-stained rim but a soft, pale, crumbly center. The most likely cause is:

The slice was too thick to process fully

The paraffin bath was overheated

The tissue stayed too long in xylene

A lymph node biopsy from a patient with suspected tuberculosis reaches reception fresh, with requests for histology and culture. What should be done?

Send a fresh portion for culture, fix the rest

Fix it all in formalin and culture the block

Freeze the whole node and send it for culture

Keep it all in saline overnight for both tests

In planning a histopathology laboratory, the work areas are arranged so that specimens:

Move one way from reception to reporting

Are handled in one shared open room

Return to reception after every stage

Pass the staining area before grossing

Histotechnology: laboratory, specimens and tissues

8 Kerala PSC Lab Technician Gr II practice questions on Histotechnology: laboratory, specimens and tissues, part of Pathology. The first 8 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 12 mm thick slice of liver is processed overnight in one cassette. Its sections show a well-stained rim but a soft, pale, crumbly center. The most likely cause is:
1. AThe paraffin bath was overheated
2. BThe flotation bath was too hot
3. CThe tissue stayed too long in xylene
4. DThe slice was too thick to process fully
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Answer: D · The slice was too thick to process fully
Fixative, alcohol, clearing agent and wax all enter tissue from the surface at a limited rate, so the center of a thick slice is reached last. A 12 mm slice is too thick for a routine schedule: the rim is fixed and impregnated, but the center stays poorly fixed and unimpregnated, so it crumbles and stains poorly. Slices for routine processing should be no more than about 3-4 mm thick. Overheated wax or long clearing would harden the whole block, not only its center.
- A: Overheated wax makes the whole block hard and brittle, not just its center.
- B: A hot flotation bath spreads or breaks sections; it cannot leave the center unprocessed.
- C: Long clearing hardens all of the tissue evenly.
Question 2 · Medium
A lymph node biopsy from a patient with suspected tuberculosis reaches reception fresh, with requests for histology and culture. What should be done?
1. AFix it all in formalin and culture the block
2. BFreeze the whole node and send it for culture
3. CSend a fresh portion for culture, fix the rest
4. DKeep it all in saline overnight for both tests
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Answer: C · Send a fresh portion for culture, fix the rest
Formalin kills mycobacteria, so tissue that has been fixed can no longer be cultured. A portion is therefore cut aseptically into a sterile container for the microbiology laboratory before the rest goes into 10% formalin for histology. The split is recorded in the specimen register and on the request form so that both reports can be traced. Delay in saline lets the tissue autolyze and lets contaminants grow.
- A: Formalin kills the bacilli, so a fixed block cannot be cultured.
- B: Freezing the whole node leaves no properly fixed tissue for paraffin sections.
- D: A night in saline lets the tissue autolyze and spoils the histology.
Question 3 · Easy
Local exhaust ventilation over the grossing bench of a histopathology laboratory is mainly needed to remove:
1. AEthanol vapor
2. BFormaldehyde vapor
3. CHot paraffin fumes
4. DXylene vapor
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Answer: B · Formaldehyde vapor
Specimens arrive in formalin and are opened and cut up at the grossing bench, so formaldehyde vapor is released there. Formaldehyde irritates the eyes and airways, sensitizes the skin and is a carcinogen. A downdraft or backdraft grossing station draws the vapor away from the worker's breathing zone. Containers should be kept closed and opened only over the extraction grill.
- A: Ethanol is used in processing and is far less hazardous than formaldehyde.
- C: Molten wax is handled at the embedding center and gives off little vapor.
- D: Xylene is used at the tissue processor and the stainer, not at the grossing bench.
Question 4 · Easy
A skin biopsy from a 50-year-old woman with blisters is sent for direct immunofluorescence. In which medium should it travel?
1. ABouin's fluid
2. BCarnoy's fluid
3. CMichel's transport medium
4. D10% neutral buffered formalin
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Answer: C · Michel's transport medium
Direct immunofluorescence looks for immunoglobulin and complement deposits in frozen sections of unfixed tissue. Fixatives alter these proteins and add background fluorescence, so the biopsy is sent fresh or in Michel's medium, a buffered ammonium sulfate solution that keeps the deposits intact for a few days. If the laboratory is close, saline-moistened gauze and immediate delivery are acceptable. A second biopsy goes into formalin for routine H&E.
- A: Bouin's fluid is a fixative, and its picric acid damages the deposits.
- B: Carnoy's fluid is a rapid fixative and is not used for direct immunofluorescence.
- D: Formalin fixation spoils frozen-section immunofluorescence.
Question 5 · Medium
In planning a histopathology laboratory, the work areas are arranged so that specimens:
1. AAre handled in one shared open room
2. BReturn to reception after every stage
3. CMove one way from reception to reporting
4. DPass the staining area before grossing
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Answer: C · Move one way from reception to reporting
A good layout follows the order of work: reception and grossing, then processing, embedding, microtomy and staining, and finally reporting and storage. A one-way flow avoids back-tracking and mix-ups, and keeps formalin-soaked specimens out of clean areas. Grossing and processing, where formalin and xylene fumes arise, are kept separate and well ventilated, away from the office and reporting rooms. Blocks and slides are then filed in a dry storage room.
- A: Fume-producing steps must be kept apart from clean and office areas.
- B: Sending specimens back to reception adds journeys and the risk of mix-ups.
- D: Grossing always comes before processing and staining.
Question 6 · Medium
Blocks of fatty breast tissue are often soft and crumble on cutting. The usual reason is:
1. AFat was not fully removed before waxing
2. BThe fat was overfixed in strong formalin
3. CFat took up excess hematoxylin
4. DThe block was cooled too quickly
Answer and explanation in LearnFree account
Question 7 · Hard
During surgery for a breast lump, the surgeon sends tissue and wants a diagnosis within 20 minutes before deciding how much to remove. In what condition should the tissue reach the laboratory?
1. AIn 10% formalin
2. BIn Bouin's fluid
3. CFresh, unfixed, sent at once
4. DIn 70% alcohol
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Question 8 · Easy
When a specimen arrives at histopathology reception, what is checked first?
1. ASize of the container
2. BLabel matches the request form
3. CFixation time completed
4. DWeight of the specimen
Answer and explanation in LearnFree account

Histotechnology: laboratory, specimens and tissues

A 12 mm thick slice of liver is processed overnight in one cassette. Its sections show a well-stained rim but a soft, pale, crumbly center. The most likely cause is:

A lymph node biopsy from a patient with suspected tuberculosis reaches reception fresh, with requests for histology and culture. What should be done?

Local exhaust ventilation over the grossing bench of a histopathology laboratory is mainly needed to remove:

A skin biopsy from a 50-year-old woman with blisters is sent for direct immunofluorescence. In which medium should it travel?

In planning a histopathology laboratory, the work areas are arranged so that specimens:

Blocks of fatty breast tissue are often soft and crumble on cutting. The usual reason is:

During surgery for a breast lump, the surgeon sends tissue and wants a diagnosis within 20 minutes before deciding how much to remove. In what condition should the tissue reach the laboratory?

When a specimen arrives at histopathology reception, what is checked first?