Vulvar Low-Grade Squamous Intraepithelial Lesion (LSIL) and Small Condyloma are Overlapping Clinicopathologic Entities

Objectives: Describe clinicopathologic features of vulvar low-grade squamous intraepithelial lesion (LSIL) and small condyloma to elaborate diagnostic criteria. Methods: Pathology database search identified vulvar biopsies reported as LSIL, wart, or condyloma. Exclusions included cancer specimens, concern for vulvar intraepithelial neoplasia (VIN), large condyloma, and inadequate slides or tissue blocks. After review of histopathology and p16, cases were designated as LSIL or condyloma, and clinical information was collected. Descriptive statistics and group comparisons were performed. Results: There were 42 women with 59 specimens; 24 patients (57%) had condyloma, 13 (31%) had LSIL, and 5 (12%) had both lesion types. Detection of LSIL/condyloma occurred as an incidental finding or secondary issue in 34 (81%). Previous or concurrent human papillomavirus (HPV)-associated VIN occurred in 23 (55%), 10 (24%) had lichen sclerosus, and 2 (5%) had graft-versus-host disease. Patients with condyloma were more likely to have negative cervicovaginal oncogenic HPV and undergo treatment than those with LSIL or both. Compared with condyloma cases, LSIL was more likely to appear flat and white or acetowhite, with smooth surface morphology on microscopy. Condyloma had a larger mean epithelial thickness and more often had elongated or irregular rete ridges. Block positive p16 was more frequent in LSIL than in condyloma. Conclusions: Vulvar LSIL and small condyloma have a subtle clinical appearance, usually identified during evaluation of another condition. While most clinicopathologic features overlap, LSIL is characterized by a smooth surface contour, normal or near-normal epithelial thickness, and a higher rate of p16 positivity than condyloma.