What are the next steps if polymorphonuclear neutrophils (PMN) are present on a Pap smear?

Management of Polymorphonuclear Neutrophils (PMN) on Pap Smear

When polymorphonuclear neutrophils (PMN) are found on a Pap smear, the patient should be evaluated for underlying infection, treated appropriately, and have a repeat Pap smear in 3 months if severe inflammation with reactive cellular changes is present. 1

Initial Assessment and Interpretation

The presence of PMNs on a Pap smear may indicate:

• Inflammation that could be non-specific or related to an infection
• Possible underlying infection such as bacterial vaginosis, Trichomonas vaginalis, or Candida 2
• "Cannon balls" or "pus balls" (neutrophils adherent to squamous cells) which may suggest Chlamydia infection 3

Management Algorithm

1. Assess Severity of Inflammation

• Mild to moderate inflammation without reactive cellular changes:

  • No immediate follow-up required if no other abnormalities are present
  • Continue routine screening schedule

• Severe inflammation with reactive cellular changes:

  • Evaluate for underlying infection
  • Treat any identified infection
  • Schedule repeat Pap smear in 3 months 1

2. Evaluate for Specific Infections

• Clinical evaluation for:
  • Bacterial vaginosis (look for clue cells - 20% or more clue cells is diagnostic) 4
  • Trichomonas vaginalis
  • Vaginal candidiasis (significantly associated with inflammation) 2
  • Chlamydia infection (especially if "cannon balls" or "pus balls" are noted) 3

3. Treatment and Follow-up

• If specific infection identified:

  • Provide appropriate antimicrobial therapy based on the pathogen
  • Treat before obtaining the repeat Pap smear 1

• Follow-up Pap smear:

  • Schedule repeat Pap smear 3 months after treatment if severe inflammation with reactive cellular changes was present 1
  • If repeat smear shows persistent abnormalities, further evaluation is needed

Special Considerations

Mucopurulent Discharge

• If a woman has obvious severe cervicitis, the Pap smear may be deferred until after antibiotic therapy to obtain an optimum smear
• If the woman is unlikely to return for follow-up, a Pap smear can be obtained after careful removal of the discharge with a saline-soaked cotton swab 5

Menstruation

• If a woman is menstruating, postpone the Pap smear and advise her to have it at the earliest opportunity 5, 1

Pregnancy

• Pregnant women should have a Pap smear as part of routine prenatal care
• A cytobrush may be used, taking care not to disrupt the mucous plug 5

Patient Education

• Many women do not understand the purpose of Pap smears or may believe they have had one when they haven't
• Provide printed information about Pap smears and their importance
• Send a copy of results to the patient when available 1
• Clearly document all test results, follow-up appointments, and management decisions 5, 1

Clinical Pearls

• The presence of PMNs alone, particularly in low numbers or during premenstrual/menstrual phases, may be a non-specific finding 3
• Inflammation on Pap smears can suggest vaginal candidiasis, which should be treated appropriately 2
• The Pap smear is not an effective screening test for STDs, but findings like PMNs can prompt additional testing 5
• Underlying cervical intraepithelial neoplasia (CIN) can be present in women with benign cellular changes, particularly in those younger than 35 years or with a history of certain infections 6