Vaginal intraepithelial neoplasia and the Pap smear

OBJECTIVE: To assess the sensitivity of the vaginal smear cytologic examination in detecting vaginal intraepithelial neoplasia (VAIN) and to evaluate the cytologic findings of cases of VAIN. STUDY DESIGN: Cases with a histologic diagnosis of VAIN were identified from the Barnes-Jewish Hospital South and North Campus over a period of five and nine years, respectively. Only posthysterectomy patients with a tissue biopsy diagnosis of VAIN and with a vaginal smear obtained within three months of the biopsy were included in the study. Pertinent clinical information was obtained by reviewing the medical records. Two pathologists reviewed the pathologic samples. RESULTS: Thirty-five vaginal smears from 31 posthysterectomy patients were included in the study. The mean age was 57 years (range, 29-84). The cytologic diagnoses of smears from patients with VAIN included: high grade squamous intraepithelial lesion (19 cases), low grade squamous intraepithelial lesion (10 cases), atypical squamous cells of uncertain significance (5 cases) and negative for malignancy (1 case). CONCLUSION: The sensitivity of the vaginal smear cytologic examination in detecting VAIN is 83%. Obscuring inflammation contributed to false negative diagnoses in two cases.