Dermoscopy in differentiated penile intraepithelial neoplasia: diagnostic clues and clinical implications

Abstract Background Penile squamous cell carcinoma is thought to arise from penile epithelial neoplasia (PeIN) via two distinct pathways: (i) infection with high-risk human papillomavirus leading to undifferentiated PeIN (uPeIN), and (ii) male genital lichen sclerosus resulting in differentiated PeIN (dPeIN). The dermoscopic features of uPeIN have been described, but those of dPeIN remain unexplored. Objectives To characterize the dermoscopic features of dPeIN. Methods Clinical and dermoscopic images from 11 patients with histopathologically confirmed dPeIN were retrospectively evaluated. Vascular morphology and distribution, structureless areas, white lines, hyperkeratosis, pigmentation and erosions were assessed. Results Most lesions (91%) were located on the glans. Erythema and vascular structures were present in 91% of cases (10 of 11). Vascular morphology was predominantly dotted/coiled (80%; 8 of 10), with fewer cases showing linear vessels (10%) or both (10%). Vessel distribution was clustered (50%), uniform (40%) or chaotic (10%). Other common features included white lines (55%; 6 of 11), hyperkeratosis (45%) and yellow structureless areas (36%). Erosion was seen in two cases, one of which lacked any background erythema or vascular structures. Conclusions The appearance of dPeIN is dermoscopically less heterogeneous than that of uPeIN. Some features closely resemble those of uPeIN, particularly erythema and glomerular or dotted vessels. White lines on an erythematous patch or erosion may be specific to dPeIN and could help differentiate between the two. Yellow structureless areas may also support the diagnosis of dPeIN.