Cytodiagnostic Problems in Cervicovaginal Smears from Symptomatic Breast Cancer Patients on Tamoxifen Therapy

Objective To evaluate the effect of tamoxifen on cervicovaginal epithelium, identify tamoxifen-related changes that mimic cancer and determine the morphologic features differentiating the 2 changes. Study Design Cervicovaginal smears from 153 conventionally treated primary breast cancer patients presenting with gynecologic symptoms were studied. Results All 153 patients presented with menorrhagia or irregular periods. Of 4 patients with a cytodiagnosis of atypical glandular changes, 2 had negative histology; 1 each had a uterine leiomyoma and endometrial hyperplasia. Of the 6 cases reported as adenocarcinoma, 3 were histologically confirmed, and the others were false positives. Conversely, 1 false negative case histologically was an endometrioid carcinoma. Conclusion Our study revealed that reactive glandular cells are a cause of false positive diagnoses. Tamoxifen-associated cellular changes can mimic morphologic features of cancer. To avoid diagnostic errors, cervicovaginal smears should be repeated after discontinuing tamoxifen treatment. Clinical correlation is mandatory. Regular follow-up with cervicovaginal smears from patients on tamoxifen treatment is recommended.