Brushings Cytology

Brushings Cytology: Diagnostic Applications in GI, Respiratory, and Urinary Tract Cancers

What is Brushings Cytology?

Brushings Cytology is a diagnostic method involving the collection of cells from internal surfaces using a cytology brush during endoscopic procedures. The smears are examined under the microscope for malignancy, infection, and inflammatory changes.

Applies To:

• Colonic Brushings Cytology
• Esophageal Brushings Cytology
• Gastric Brushings Cytology
• Oropharyngeal Brushings Cytology
• Small Bowel Brushings Cytology
• Urinary Brushings Cytology

Test Usually Includes:

If the brush is submitted in physiological saline, cytocentrifuge preparations can be made. Otherwise, direct smears are prepared from the collected cells.

Patient Preparation:

Obtain informed consent prior to the procedure. No special fasting or dietary restrictions unless specified by the physician.

Specimen Collection:

• Instrument: Flexible fiberoptic bronchoscope or endoscope
• Container: Coplin jar containing 95% ethanol
• Procedure:
  • Roll the brush gently over a fully frosted labeled slide.
  • Fix the smear immediately in 95% ethanol to preserve cellular details.
  • Clearly indicate the brushed site on both the slide and requisition form.
  • Send a sterile double-sheathed brush for culture if infection is suspected.

Causes for Sample Rejection:

• Hypocellularity (too few cells)
• Improper fixation or air-drying
• Unlabeled slides

Special Instructions:

Always indicate the exact site brushed and provide full clinical history. Note if special stains for fungi, parasites (e.g., amebas), or viral agents are required.

Uses:

Brushings cytology helps to:

• Diagnose primary or metastatic tumors
• Detect infections from:
  • Herpesvirus, Cytomegalovirus (CMV), Measles
  • Fungal infections (e.g., Candida, Histoplasma)
  • Parasites: Strongyloides, Echinococcus, Giardia, Entamoeba
  • Pneumocystis carinii (P. jirovecii)
  • Legionella pneumophila (Legionnaires’ disease)
• Perform immunocytochemical staining for tumor or bacterial antigens

Limitations:

Reliable interpretation requires proper fixation. If smears dry out, they become cytologically uninterpretable. However, if air drying is < 30 minutes, rehydration in normal saline for 30 seconds followed by fixation may make the smears usable.

A strong clinical history is crucial. For example, post-tracheostomy atypia may mimic squamous cell carcinoma, requiring clinical correlation.

Additional Notes:

Special cultures and stains may be necessary when infection or inflammation is suspected. Immunostaining enhances the diagnostic accuracy of certain pathologies.

References

• Chambers LA, Clark WE. Acta Cytol, 1986; 30:110–114.
• Cook JJ, Haneman B. Acta Cytol, 1988; 32:461–464.
• Geisinger KR, et al. Cancer, 1992; 69(1):8–16.
• Jeevanandaur V, et al. Gastrointest Endosc, 1987; 33:370–371.
• Melville DM, et al. Am J Clin Pathol, 1988; 41:1180–1186.
• Jacobs, Demott, Finley, et al. Laboratory Test Handbook, Lexi-Comp Inc, 1994.