MLT GlobeHisto & Cyto Techniques: Cytology – page 2
80 Histo & Cyto Techniques MCQs on Cytology with answers and explanations.
A CSF sample with very few cells must be concentrated onto a small slide area. Which instrument is used?
A cytocentrifuge spins cells directly onto a defined slide spot at low speed, ideal for sparsely cellular fluids.
Sputum smears made for Pap staining are wet-fixed in:
95% ethanol is the standard Pap fixative; weak alcohol does not fix, formalin impairs Pap staining, and xylene is a clearing agent.
A body fluid volume is too small to balance in the centrifuge. What can be added without damaging the cells?
Isotonic saline keeps cells intact; hypotonic water causes swelling and lysis, and ethanol would fix and clump the cells.
Which specimen is processed in histopathology rather than in cytology?
Solid tissue fragments are processed into paraffin sections; fluids, discharges and smears are cytology specimens.
A conventional Pap smear was left to air-dry for several minutes before being placed in 95% ethanol. What change is expected?
Pap staining requires immediate wet fixation. Air-drying causes nuclei to enlarge and stain pale, obscuring chromatin detail and making interpretation difficult.
In the Bethesda System, high-grade squamous intraepithelial lesion (HSIL) includes which histologic lesions?
HSIL covers moderate and severe dysplasia (CIN 2, CIN 3) and carcinoma in situ. CIN 1 is LSIL; invasive carcinoma is a separate category.
What is the main advantage of preparing a cell block from residual FNA material or fluid sediment?
A cell block concentrates cells, which are processed and embedded like tissue. Multiple sections can then be cut for immunohistochemistry, special stains and molecular tests.
A sputum sample for cytology is considered representative of the lower respiratory tract when it contains:
Alveolar macrophages come from the deep lung, so their presence confirms a satisfactory sample. Many squamous cells without macrophages indicate saliva.
A cervical smear shows multinucleated cells with nuclear molding, chromatin pushed to the nuclear edge and a ground-glass appearance. The most likely cause is:
Multinucleation, molding and margination of chromatin (the '3 Ms') are typical of herpes simplex virus infection. HPV produces koilocytes rather than multinucleated molded cells.
Fine needle aspiration cytology is usually performed with a needle of what gauge?
Thin 22–25 G needles collect cells with minimal trauma. Wider needles (14–18 G) are used for core biopsies that yield tissue for histology.
Adding heparin to serous effusions collected for cytology mainly helps because it:
Clotting traps cells in fibrin. Anticoagulated fluid spins into a buffy coat where malignant cells layer, and cells spread and adhere well on slides.
Which cytology specimen must be chilled and processed within minutes because acid rapidly destroys cells?
Hydrochloric acid and pepsin digest exfoliated cells in gastric material. Serous fluids are protein-rich and relatively protective.
Fresh cytology specimens low in protein and mucus, such as urine, remain adequate under refrigeration for only about:
Without protective protein or mucus, cells degenerate quickly and should be processed or pre-fixed promptly. Protein-rich fluids tolerate longer refrigeration.
Which specimen has a high protein content that helps protect cells before fixation?
Effusions contain abundant protein, preserving cells for hours. Urine and CSF are protein-poor, and gastric acid destroys cells.
Mucus-rich specimens such as sputum, if refrigerated unfixed, generally remain usable for up to:
Mucus coats and protects cells, so refrigerated sputum can wait about 12–24 hours. Protein- and mucus-poor fluids deteriorate within hours.
To limit bleeding, an endocervical cytobrush should be rotated no more than about:
A quarter to half turn collects enough endocervical cells; more rotation causes bleeding that obscures the smear. Brooms, by contrast, are rotated fully several times.
An unfixed cytology specimen deteriorates fastest when it has:
Enzymes digest cells rapidly, so such specimens need immediate processing. Protein and mucus protect cells, and neutral pH is favorable.
In the Papanicolaou stain, orange G (OG-6) mainly stains:
OG-6 is the first cytoplasmic counterstain, coloring keratin orange. Hematoxylin stains nuclei, and EA stains non-keratinized cytoplasm pink or green.
Which statement about the cervical squamocolumnar junction is correct?
The junction moves with puberty, pregnancy and menopause, creating the transformation zone where metaplastic cells are vulnerable to HPV. Adequate smears must sample it.
For hormonal (maturation index) evaluation, the vaginal smear is best taken from:
Lateral wall cells respond to hormones and are free of cervical contamination. The posterior fornix pool contains mixed, degenerated cells.