Vaginal intraepithelial neoplasia: Reproducibility of pathologic diagnosis and correlation of smears and biopsies

Masked slides of 124 vaginal smears and 70 corresponding biopsies obtained from 45 patients with a reported cytologic diagnosis of vaginal intraepithelial neoplasia (VAIN) were examined by two pathologists to assess the interobserver reproducibility and histopathologic correlation of cytopathologic diagnoses of VAIN. The cytopathologic diagnoses by the two pathologists were identical in 94 (76%) cases and matched the originally reported diagnosis in 45 (46%) cases. The histopathologic diagnoses by the two pathologists agreed in 47 (67%) cases and matched the originally reported diagnosis in 35 (55%). The consensus cytopathologic and histopathologic diagnoses rendered by the pathologists agreed within one grade in 49 (70%) cases. A consensus histopathologic diagnosis of VAIN 2 was rendered in only 1 (10%) of 10 cases in which the cytopathologic diagnosis was VAIN 2. These results suggest that the cytopathologic and histopathologic grading of VAIN is moderately reproducible. Because (1) combining VAIN 2 and 3 under the diagnosis of high grade squamous intraepithelial lesion provided a slight improvement in diagnostic reproducibility and cytopathologic-histopathologic correlation and (2) the cytopathologic diagnosis of VAIN 2 was employed rarely and rarely confirmed histopathologically, we advocate the use of the term high grade squamous intraepithelial lesion to designate VAIN 2 and 3.