Diagnostic value of reflectance confocal microscopy in papular dermatoses of the female vulva.

Objectives: Papular dermatoses commonly affecting the female vulva, such as molluscum contagiosum, syringoma, lymphangioma, folliculitis, verruca vulgaris, ectopic sebaceous glands, and bowenoid papulosis, often present with similar clinical appearances and are frequently misdiagnosed. This study aims to explore the clinical diagnostic value of reflectance confocal microscopy (RCM) in differentiating these conditions.

Methods: A retrospective analysis was conducted on RCM imaging and histopathological findings from lesion sites in 172 female patients with vulval papular dermatoses. RCM characteristics confirmed by biopsy were summarized and diagnostic clues were explored.

Results: RCM diagnosis was consistent with histopathological diagnosis in 147 out of 172 cases (85.47%). Molluscum contagiosum, syringoma, lymphangioma, and folliculitis all exhibited cystic-like structures under RCM, differing in the location of the structures, wall characteristics, internal contents, and reflectivity. Verruca vulgaris, ectopic sebaceous glands, and bowenoid papulosis lacked such structures. Verruca vulgaris showed distinctive low-refractive vacuolated cells in the spinous layer; bowenoid papulosis exhibited mild cytologic atypia in the spinous layer; ectopic sebaceous glands were characterized by moderately to low-refractive, fish roe-like sebaceous lobules within the dermis.

Conclusions: RCM enables noninvasive, real-time, and dynamic visualization of key diagnostic and differential features of common vulvar papular dermatoses in women, offering high diagnostic value.