18: Exfoliative Cytology

Microscopic study of cells desquamated (shed) from epithelial surfaces.

What is exfoliative cytology?

Constant cellular turnover and replacement

What is the physiologic basis of exfoliative cytology?

Due to decreased intercellular adhesion.

Why do malignant cells shed more readily than normal cells?

Cancer staging, precancerous screening, and infection detection.

What are the major clinical indications of exfoliative cytology?

Barr body

What genetic structure is identified for sex determination in cytology?

Naturally voided fluids like urine, sputum, and vaginal secretions.

What type of fluids are examined in spontaneous collection?

Spatula or brush

What instrument is commonly used in mechanical collection?

To irrigate a cavity and dislodge cells.

What is the purpose of washing techniques in cytology?

Cervical, vaginal, and endometrial surfaces

What are the common collection sites in gynecologic cytology?

Detection of cervical cancer at the precancerous stage

What is the primary purpose of Pap smear screening?

Viral, bacterial, and fungal infections

Which infections can be identified through cytologic smears?

Early intervention before lesions become invasive.

What is the prevention goal in exfoliative cytology?

Sputum

What specimen is collected in respiratory cytology?

Saccomanno fluid

What fluid is commonly used for sputum fixation?

Creamy appearance

What is the ideal characteristic of an FNA aspirate?

Direct smears, imprint smears, and pull technique

What are the three smear preparation methods mentioned?

Centrifugation and Cytospin preparation

What concentration methods are used for low-cellularity fluids?

95% ethanol

What is the universal gold standard fixative for wet fixation?

Carnoy’s fixative

What specialized fixative is used for bloody specimens?

Saccomanno fluid

What fixative is preferred for sputum and washings?

Preservation of nuclear detail

What is the main purpose of wet fixation?

Cellular distortion

What artifact results from air drying?

Blood films and bone marrow smears

Which smears are usually air-dried instead of wet-fixed?

Superficial, intermediate, and parabasal cells

What are the three squamous maturation cell types?

Superficial cells

Which squamous cells are large with pink acidophilic cytoplasm?

Intermediate cells

Which squamous cells are medium-sized with vesicular nuclei?

Parabasal cells

Which squamous cells are small with dense basophilic cytoplasm?

Birth to puberty, after childbirth, and after menopause

When are parabasal cells normally seen?

Nuclear-to-cytoplasmic ratio

What is the key identification marker between squamous cell layers?

High estrogen

What do superficial cells indicate hormonally?

Progesterone influence

What do intermediate cells indicate hormonally?

Low hormonal stimulation

What do parabasal cells indicate hormonally?

Boat-shaped intermediate cells with folded edges

What are navicular cells?

Combined estrogen-progesterone effect.

What hormonal effect do navicular cells indicate?

Honeycomb appearance

What is the appearance of endocervical cells in clusters?

Up to 10 days after menstruation

When are endometrial cells normally seen?

Upper lateral third of the vaginal wall.

What is the best site for hormonal cytology sampling?

10x objective

What objective is first used in hormonal assessment?

40x objective

What objective is used for MI calculation?

Ratio of parabasal, intermediate, and superficial cells.

What is the maturation index (MI)?

False pink staining due to drying or infection

What does pseudo-acidophilia refer to?

Fibers trap diagnostic cells and cause drying artifacts.

Why should cervical smears avoid cotton swabs?

It collects more epithelial layers.

Why is a cytobrush preferred over cotton swabs?

Patient ID, date, and specimen type.

What must be included in slide labeling?

Fix smears immediately while wet.

What is the golden rule of fixation?

It is saliva and considered unsatisfactory.

What happens if sputum lacks alveolar macrophages?

Presence of alveolar macrophages.

What confirms a true sputum specimen?

Blood-flecked or solid particles.

What sputum specimen is preferred for diagnosis?

Within 30 minutes

What is the preferred timing for gastric secretion examination?

Gastric acid digests cells

Why must gastric specimens be processed quickly?

Non-lactational discharge

What is considered abnormal in nipple discharge cytology?

Ulcerated lesions or lymph nodes.

What is an imprint smear used for?

Washings, brushings, and aspirates

What bronchoscopy specimens can be collected?

Two-slide pull method to create a uniform monolayer.

What is the “pull technique” used in bronchial brushing?

25-gauge needle

What gauge needle is commonly used in FNA?

10-mL syringe

What syringe size is commonly used in FNA?

Deep lesions.

Which lesions require CT or ultrasound guidance in FNA?

Four slides.

What is the maximum recommended number of slides in FNA preparation?

Hematoxylin.

Which stain in Pap stain provides blue-black nuclear detail?

Keratin bright orange.

What does OG-6 specifically stain?

Differentiates cell types.

What is the function of EA-36 stain?

Cytoplasmic transparency.

What is the key advantage of Pap stain?

Romanowsky stain.

What stain is ideal for air-dried smears?

Cytoplasm, granules, and vacuoles.

What cellular structures are best studied with Romanowsky stain?

Shifts color toward blue.

How does alkaline pH affect Romanowsky staining?

Shifts color toward red.

How does acidic pH affect Romanowsky staining?

To remove loose cells and precipitates.

Why should staining solutions be filtered daily?

Loose contaminating cells causing cross-contamination.

What are “floaters” in cytology?

12 inches (30 cm).

What distance should spray fixatives be held from slides?

Cells may blast off the slide.

What can happen if spray fixative is too close?

It lyses red blood cells.

Why is Carnoy’s fixative useful in hemorrhagic samples?

OG-6 and EA-36.

Which Pap stain components lose potency faster than hematoxylin?

Weekly or when muddy.

How often should OG-6 and EA-36 be replaced?

To prevent slides from sticking together.

Why are paper clips placed between slides in fixative jars?

Approximately 1.5.

What is the refractive index preferred for mounting media?

To avoid air bubbles.

Why should mounting medium match the clearing agent solvent?

Toluene or xylene.

Which clearing agent is commonly paired with xylene-compatible mounting media?

Detect specific antigens in cells

What is the role of immunohistochemistry (IHC) in cytology?

Antibody-antigen binding.

What interaction forms the basis of IHC?

Better reagent penetration and tissue-like structure.

Why are cell blocks preferred for IHC?

Intact cell membranes reduce reagent penetration.

What is a cytology limitation in IHC?

PCR and sequencing.

What molecular technique detects mutations from few malignant cells?

FISH

What is the gold standard method for Her2/neu assessment?

Trastuzumab

Which targeted therapy is associated with Her2-positive cases?

Oxidation and fading of slides.

What happens if water contaminates final alcohol or xylene baths?

Normal saline

What solution can restore cloudy air-dried smears?

Contaminated staining solutions.

What does frequent observation of bacteria or fungi across cases suggest?

4% formaldehyde and 65% ethanol.

What is the composition of the 4/65 speed fix?

Reduce fixation and staining time.

What is the purpose of the 4/65 speed fix?

Personalized genetic medicine.

What is the future focus of cytology according to molecular cytopathology?