Page 283 - Textbook of Pathology, 6th Edition

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  TABLE 11.2: Differences between Exfoliative and Interventional Cytology.
Feature Exfoliative Cytology Interventional Cytology
1. Cell samples Exfoliated from epithelial surfaces Obtained by intervention/aspiration
2. Smears Require screening to locate Abundance of cells for study in most
suitable cells for study smears CHAPTER 11
3. Diagnostic basis Individual cell morphology Cell patterns and morphology of groups of cells
4. Morphologic criteria of Nuclear characteristics most Nuclear characteristics important; cytoplasmic
diagnostic significance important character and background equally significant

do not routinely require surgical intervention e.g. with the patient in contrast to exfoliative cytology where
Hashimoto’s thyroiditis. the samples are prepared and forwarded by the clinician to
5. Diagnosis of specific infections. A variety of bacterial, the pathologist and the cytopathologist interprets them in
viral, protozoal and fungal infections can be identified by isolation.
cytologic methods e.g. tubercle bacilli in lymph node A brief account of both main branches of cytology is Basic Diagnostic Cytology
aspirates, herpetic inclusions and Trichomonas in cervico- given below while their contrasting features are presented
vaginal smears, fungal hyphae in touch preparations from in Table 11.2.
draining sinuses.
6. Cytogenetics. Cytodiagnostic techniques can be emplo- EXFOLIATIVE CYTOLOGY
yed for chromosomal studies including leucocyte and tissue
cultures and for demonstrating sex-chromatin e.g. buccal Type of samples that can be obtained from different organ
smear for Barr body. systems for exfoliative cytodiagnosis are listed in Table 11.3.
Apparently, a comprehensive review of each type of sample
7. Assessment of hormonal status in women. Vaginal is beyond the scope of this text. Cytology of female genital
smears accurately reflect changes in female sex hormonal tract is discussed in detail below while brief mention is made
levels e.g. to confirm the onset of menopause.
about other samples.
8. Identification of cell of origin. For example, identifi-
cation of spermatogenic elements in aspirates from the testes I. FEMALE GENITAL TRACT
in cases of male infertility.
For cytomorphological recognition of cancer, nuclear charac- Smears from the female genital tract have traditionally been
teristics are used to determine the presence or absence of known as ‘Pap smears’. These smears may be prepared by
malignancy (Table 11.1). Cytoplasmic characteristics help in
typing the malignancy e.g.keratinisation in squamous cell   TABLE 11.3: Types of Samples for Exfoliative Cytology
carcinoma, mucin droplets in adenocarcinoma, melanin Obtainable from Different Organ Systems/Body Sites.
pigment in melanomas. 1. Female genital tract — Lateral vaginal smears (LVS)
— Vaginal ‘pool’ smears
Branches of Diagnostic Cytology — Cervical smears
— Combined (fast) smears
Two branches of diagnostic cytology are currently recog- — Triple smears (CVE)
nised: exfoliative and interventional. — Endocervical/Endometrial
aspiration
EXFOLIATIVE CYTOLOGY. This is the older branch that
essentially involves the study of cells spontaneously shed 2. Respiratory tract — Sputum
Bronchial washings/brushing/
—
off (as a result of continuous growth of epithelial linings) bronchioalveolar lavage (BAL)
from epithelial surfaces into body cavities or body fluids. 3. Gastrointestinal tract — Endoscopic lavage/brushing
Exfoliative cytology is facilitated by the fact that the rate of
exfoliation is enhanced in disease-states thereby yielding a 4. Urinary tract — Urinary sediment
—
Bladder washings
larger number of cells for study. In addition, cells for study — Retrograde catheterisation
may also be obtained by scraping, brushing, or washing — Prostatic massage (secretions)
various mucosal surfaces (abrasive cytology). 5. Body fluids — Effusions
— Fluids of small volume
INTERVENTIONAL CYTOLOGY. This is the branch in i. Cerebrospinal fluid (CSF)
which samples are obtained by clinical procedures or ii. Synovial fluid
surgical intervention. It is dominated by, and is virtually iii. Amniotic fluid
synonymous with, Fine Needle Aspiration Cytology iv. Hydrocele fluid
(FNAC) which is also known as Aspiration Biopsy Cyto- v. Seminal fluid (semen)
logy (ABC). In interventional cytology, the cytopathologist vi. Nipple discharge
often performs the clinical procedure himself and interacts 6. Other samples — Buccal smears (for sex chromatin)