Cytology: specimens, fixation and Pap staining

57 Kerala PSC Lab Technician Gr II practice questions on Cytology: specimens, fixation and Pap staining, part of Pathology. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium

   A cervical smear taken at a routine visit is reported unsatisfactory because blood covers most of the cells. Which collection error is most likely?

   1. AFixed at once in 95% ethanol
   2. BCollected during menstruation
   3. CCollected with an Ayre spatula
   4. DCollected at mid-cycle

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   Answer: B · Collected during menstruation

   Menstrual blood dilutes and covers the squamous cells, and endometrial cells and histiocytes add to the clutter. Cervical smears are best taken around mid-cycle, never during menstruation. The woman should also avoid douching, vaginal medicines and intercourse for a day or two before the test. The Ayre spatula and immediate fixation in 95% ethanol are correct practice.

   • A: Immediate fixation in 95% ethanol is correct practice.
   • C: The Ayre spatula is the standard sampling tool.
   • D: Mid-cycle is the best time and gives clean smears.

2. Question 2 · Medium

   Cervical smears fixed with a spray (coating) fixative are first soaked in 95% alcohol before Pap staining, in order to:

   1. ARestore cells that air-dried first
   2. BRehydrate the cells before OG-6
   3. CDissolve the polyethylene glycol coat
   4. DWash the mucus off the smear

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   Answer: C · Dissolve the polyethylene glycol coat

   Spray fixatives contain alcohol and polyethylene glycol (Carbowax). The alcohol fixes the cells and evaporates, leaving a wax film that protects the smear during transport. This film must be dissolved in alcohol before staining, or the stains penetrate unevenly. Cells that dried before they were sprayed stay damaged whatever is done later.

   • A: Cells that air-dried before spraying are permanently damaged.
   • B: Rehydration comes later, through graded alcohols to water before hematoxylin.
   • D: The soak removes the fixative coat, not mucus.

3. Question 3 · Hard

   A 16-year-old girl has short stature and no breast development. Her buccal smear shows no Barr body in 200 well-preserved cells. Which condition is most consistent with this?

   1. ATriple X female (47,XXX)
   2. BKlinefelter syndrome (47,XXY)
   3. CTurner syndrome (45,X)
   4. DNormal female (46,XX)

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   Answer: C · Turner syndrome (45,X)

   The number of Barr bodies in a cell is one less than its number of X chromosomes. A 45,X cell has a single active X and therefore no Barr body. Short stature and absent puberty with a sex chromatin-negative smear in a girl point to Turner syndrome. The diagnosis is confirmed by karyotyping, which also detects mosaics.

   • A: 47,XXX cells show up to two Barr bodies.
   • B: 47,XXY cells have two X chromosomes and show one Barr body.
   • D: A normal female shows one Barr body in a good proportion of cells.

4. Question 4 · Hard

   After mounting, a batch of Pap-stained smears looks milky and hazy, with fine droplets that blur the cells. The most likely cause is:

   1. AWater carried over into the xylene
   2. BExhausted OG-6 solution
   3. COverstaining with hematoxylin
   4. DAir-drying before fixation

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   Answer: A · Water carried over into the xylene

   Water left in the smear by worn-out final alcohols is carried into the xylene. Water and xylene do not mix, so fine droplets form and the mount looks milky. The coverslip is removed in xylene, and the slide is taken back through fresh absolute alcohol and fresh xylene and remounted. The last alcohols and xylene in the staining line are then changed.

   • B: Weak OG-6 only reduces the orange color of keratinized cells.
   • C: Hematoxylin overstaining darkens nuclei but does not cloud the mount.
   • D: Air-drying enlarges cells and blurs nuclear detail without milky droplets.

5. Question 5 · Easy

   What is the Barr body seen against the nuclear membrane of buccal cells?

   1. AA pair of autosomes
   2. BAn inactivated X chromosome
   3. CA prominent nucleolus
   4. DA condensed Y chromosome

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   Answer: B · An inactivated X chromosome

   In cells with more than one X chromosome, all but one X are inactivated early in embryonic life (the Lyon hypothesis). The inactive X stays condensed and appears as a small dark plano-convex body against the inner nuclear membrane. The number of Barr bodies is one less than the number of X chromosomes. It is seen in a proportion of normal female cells but not in normal male cells.

   • A: Autosomes do not form sex chromatin.
   • C: Nucleoli lie within the nucleus and are not sex chromatin.
   • D: The Y chromosome gives the fluorescent F body with quinacrine, not the Barr body.

6. Question 6 · Easy

   In the Papanicolaou stain, OG-6 stains the cytoplasm of:

   1. AKeratinized squamous cells
   2. BNeutrophils and histiocytes
   3. CParabasal squamous cells
   4. DColumnar endocervical cells

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7. Question 7 · Medium

   Why is the first scraping of the cheek discarded when a buccal smear is made for sex chromatin?

   1. AIt has too few cells for a smear
   2. BIt is mostly blood and leukocytes
   3. CIt is made up mostly of deep basal cells
   4. DIt holds degenerate cells and debris

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8. Question 8 · Medium

   A 60-year-old smoker with suspected lung cancer is asked for sputum cytology. Which sample is best?

   1. AEarly-morning deep-cough sputum on 3 days
   2. BA throat swab taken at the clinic
   3. CSaliva collected after the evening meal
   4. DA single 24-hour pooled sputum sample

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9. Question 9 · Easy

   Besides eosin Y and light green SF, the classic EA counterstain of the Pap method contains:

   1. AMethylene blue
   2. BHematoxylin
   3. COrange G
   4. DBismarck brown

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10. Question 10 · Easy

    Exfoliative cytology is the study of cells that:

    1. AAre drawn from a lump with a needle
    2. BAre cut from paraffin-embedded tissue
    3. CAre shed or scraped from body surfaces
    4. DAre grown in a tissue culture flask

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11. Question 11 · Easy

    Shorr stain on vaginal smears is used mainly to assess:

    1. ABacterial vaginosis
    2. BCervical cancer screening
    3. CSex chromatin (Barr bodies)
    4. DHormonal (estrogen) status

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12. Question 12 · Hard

    A lateral vaginal wall smear from a 62-year-old woman, stained by the Shorr method, gives a maturation index of 85/15/0 (parabasal/intermediate/superficial). What does this indicate?

    1. AA normal pre-ovulatory smear
    2. BAtrophy due to low estrogen
    3. CProgesterone (luteal) effect
    4. DStrong estrogen effect

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13. Question 13 · Medium

    A pleural fluid for cytology will reach the laboratory only after several hours. How should it be held meanwhile?

    1. AIn a refrigerator at about 4 °C
    2. BIn a freezer at -20 °C
    3. CWith an equal volume of formalin
    4. DIn an incubator at 37 °C

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14. Question 14 · Medium

    A 58-year-old woman has postmenopausal bleeding. Which conventional smear is most likely to contain shed endometrial cells?

    1. APosterior fornix (vaginal pool) aspirate
    2. BBuccal mucosa scraping
    3. CEctocervical scraping with an Ayre's spatula
    4. DLateral vaginal wall scraping

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15. Question 15 · Easy

    In blood films from normal females, sex chromatin appears in a few neutrophils as:

    1. AHowell-Jolly bodies
    2. BDöhle bodies
    3. CToxic granules
    4. DDrumsticks

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16. Question 16 · Easy

    A wet-fixed cervical smear should stay in 95% ethanol for at least:

    1. A24 hours
    2. B15 minutes
    3. C2 minutes
    4. D30 seconds

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17. Question 17 · Medium

    When smears are made from the sputum of a 58-year-old smoker, which part should be picked for smearing?

    1. AAny part, as it is evenly mixed
    2. BFrothy saliva at the surface
    3. CBlood-streaked or opaque grey particles
    4. DThe clear, watery top layer

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18. Question 18 · Hard

    A new batch of Pap-stained cervical smears shows reddish-purple nuclei with poor chromatin detail; cytoplasmic colors are normal. Bluing is done in the laboratory's tap water, which tests at pH 6.0. The most likely cause is:

    1. AExhausted OG-6 counterstain solution
    2. BWater carried into the final xylene
    3. CInadequate bluing of the hematoxylin
    4. DOverstaining in the EA counterstain

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19. Question 19 · Medium

    Why is a little heparin added to a pleural fluid collected for cytology from a 65-year-old man?

    1. ATo lyse red cells in a bloody fluid
    2. BTo fix the cells before they degenerate
    3. CTo stop clots forming that trap cells
    4. DTo dissolve mucus in the fluid

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20. Question 20 · Easy

    A Tzanck smear, made by scraping the base of a fresh blister, is used mainly to detect:

    1. AFungal hyphae of dermatophytes
    2. BBarr bodies for sex chromatin
    3. CAcid-fast bacilli of leprosy
    4. DMultinucleated giant cells of herpes

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21. Question 21 · Medium

    Gastric washings from a 60-year-old man with suspected gastric cancer are collected on ice and processed at once because:

    1. ABile pigment stains the cells green
    2. BAcid and enzymes quickly digest the cells
    3. CMucus sets into a gel at room temperature
    4. DThe cells multiply rapidly when warm

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22. Question 22 · Hard

    In a lateral vaginal wall smear from a 28-year-old woman, 200 mature (superficial and intermediate) squamous cells are counted; 130 have small pyknotic nuclei. What is the karyopyknotic index, and what does it suggest?

    1. A35%, progesterone (luteal) effect
    2. B65%, atrophy from low estrogen
    3. C65%, estrogen effect (near ovulation)
    4. D65%, progesterone (luteal) effect

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23. Question 23 · Medium

    How should cervical material on the spatula be spread on the slide?

    1. ARubbed back and forth several times
    2. BThinly, in one or two smooth strokes
    3. CPressed hard under a second slide
    4. DAs a thick blob left in the centre

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24. Question 24 · Easy

    The fixative Papanicolaou originally used for cervical smears was 95% ethanol mixed in equal parts with:

    1. AEther
    2. BMethanol
    3. CFormalin
    4. DAcetone

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25. Question 25 · Medium

    CSF from a 7-year-old boy with leukemia is sent for cytology. Why must it be processed within about an hour?

    1. AIts low protein lets cells degenerate fast
    2. BLeukemic cells use up all its glucose
    3. CIts cells multiply at room temperature
    4. DIt clots quickly and traps the cells

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