Page 289 - Textbook of Pathology, 6th Edition

alveolar lavage (BAL) during bronchoscopy allows 2. High-grade papillary tumours, sessile tumours and carci- 273
localisation of lesions to specific areas of the respiratory tract. noma in situ where urothelial cells exhibit cytomorphological
Moreover, specimens are easier to study as the cellularity is abnormalities, are readily diagnosed by urinary cytology.
less than that of sputum. However, bronchoscopic 3. Urothelial tumours are often synchronous or meta-
procedures are unpleasant for patients, time-consuming and chronous and may involve different regions of the urinary tract.
require considerable expertise. Urinary cytology is, thus, of immense value in the follow-up CHAPTER 11
of patients with previously diagnosed urothelial tumours.
III. GASTROINTESTINAL TRACT
Lesions in the oral cavity may be sampled by scraping the V. BODY FLUIDS
surface with wooden and metal tongue-depressors. For the For the sake of convenience, the cytology of body fluids can
oesophagus and stomach, samples are obtained under direct be discussed under following two headings:
vision by brushing or lavage through fibreoptic endoscopes. A. Effusions in body cavities
For cytologic samples from the stomach, the older method B. Fluids of small volume.
of blind lavage through a Ryle’s tube using isotonic saline or
Ringer’s solution have largely been replaced nowadays by A. EFFUSIONS
direct mucosal visualisation by the endoscopist and collection
of cytologic sample while doing a biopsy. Cytology samples Effusion refers to the accumulation of fluid in any of the three Basic Diagnostic Cytology
from the colon may also obtained by brushing during body cavities (pleural, pericardial and peritoneal). An
colonoscopy or lavage following enema to clean the colon. effusion in the peritoneal cavity is also known as ascites.
Effusions have traditionally been classed as transudates or
exudates. This distinction is important in diagnostic cytology
IV. URINARY TRACT
as malignant effusions are invariably exudates with a protein
1. URINARY SEDIMENT CYTOLOGY. Cytological content greater than 3 gm/dl (see Table 5.1, page 96).
evaluation of the urinary tract is most often carried out by Diagnostic cytology of effusions on samples obtained by
examining the sediment of voided or catheterised specimens paracentesis is mainly related to the identification of
of urine. It is convenient for the patient and a useful method malignancy, and wherever possible, its classification. In
for study of both the upper and lower urinary tracts, provided benign effusions, cytological findings are mostly non-specific.
the samples are collected and processed in the correct manner
(page 276). While voided specimens are satisfactory in men, Cellular Components in Effusions
catheterisation is often preferred in women to avoid contami- Two main primary component cells of effusions are
nation by vaginal cells and menstrual blood. mesothelial cells and macrophages or histiocytes. Effusion

2. BLADDER IRRIGATION (WASHINGS). Washings of causes disruption of the mesothelial lining and these cells
the urinary bladder obtained at cystoscopy are preferred in collect in the fluid individually or as small groups.
symptomatic patients when bladder tumours are suspected. Macrophages appear as mononuclear cells of the size of
The procedure provides excellent cytological preparations. mesothelial cells distributed singly or as loose clusters.
However, macrophages have ill-defined cell border
3. RETROGRADE CATHETERISATION. For suspected compared to mesothelial and may have cytoplasmic
lesions of the upper urinary tract, voided urine is usually vacuoles. Moreover, the nuclei in the macrophages are
satisfactory. While renal parenchymal cells are infrequent in eccentric and kidney-shaped while those of mesothelial cells
urine, material obtained from the renal pelvis and ureter are central and round.
contains adequate quantity of these cells. In some instances, In addition, the effusion may have the following cellular
retrograde catheterisation and brushing of the ureter and components:
renal pelvis are utilised for localisation of lesions.
CELLS IN BENIGN EFFUSIONS. These include reactive
4. PROSTATIC MASSAGE. Prostatic secretions are proliferations of mesothelial cells in inflammation,
obtained by prostatic massage and the sample is collected polymorphonulcear neutrophils in acute suppurative
directly onto a glass slide and smeared. The procedure is inflammation, and lymphocytes in chronic fluid collections.
rarely used nowadays with the advent of direct sampling of When lymphocytes are dominant cells in the effusion fluid
the prostate by FNAC. in fibrin-rich background, the possibility of tuberculosis is
considered. In tuberculous effusions, granulomas, epithelioid
Diagnostic Utility of Urinary Cytology cells or Langhans’ giant cells may not be seen; stain for
tubercle bacilli may sometimes be of value.
While evaluating the utility of urinary cytology in the diag-
nosis of urothelial tumours, following aspects need to be kept CELLS IN MALIGNANT EFFUSIONS. Malignant cells in
in mind: effusion may of origin from primary tumour (e.g.
1. Papillary tumours of low-grade are lined by urothelium mesothelioma) or from secondary/metastatic tumour; the
showing no morphological abnormalities or only slight latter being more common the case.
cellular and nuclear abnormalities. Such tumours cannot be Mesothelioma. It is uncommon and is more often epithelial
diagnosed on cytologic material with any degree of certainty. type since fibrous mesothelioma does not exfoliate cells in