Penile lichen sclerosus: Correlation between histopathologic features and risk of cancer

The relationship between penile lichen sclerosus (LS) and cancer development has not been clearly assessed so far. In order to define these histological features of LS that may indicate or precede a malignant degeneration, 104 biopsy specimens from 86 patients with LS of the glans (90.5%) and from 9 patients with a penile malignancy (7 squamous cell carcinomas, 1 in situ carcinoma, and 1 verrucous carcinoma) arising on LS (9.5%) were reviewed. Three different histopathologic LS patterns were identified: pattern 1 with a prominent lichenoid inflammatory infiltrate in the dermis (9%), pattern 2 characterized by a band-like infiltrate separated from the epidermis by a band of dermal sclerosis (44%), and pattern 3 showing prominent sclerosis with minimal or absent inflammatory infiltrate (9%). These patterns have previously been described in vulvar LS, and have been considered typical of early, mature, and late LS, respectively. In our study, we also found a fourth pattern in 38% of cases, with overlapping features between the first and third pattern, occasionally showing areas of epidermal thickening, with loss of the normal keratinocyte cytoarchitectural differentiation, mitoses and apoptotic cells. In our opinion, the histological features observed in this last pattern may be interpreted as areas of disease reactivation within a chronic stage. Furthermore, 7 out of 9 cases of penile cancer from our series (78%) were associated with this pattern, suggesting that it may correlate with a malignant degeneration.