Squamous cell carcinoma arising in hypertrophic lichen planus

Abstract

Hypertrophic lichen planus (HLP) is a chronic T-cell-mediated inflammatory disease characterised by pruritic hypertrophic or verrucous plaques on the lower limbs. We report a case of an 87-year-old woman with a 12-year history of HLP on both lower legs presenting with malignant transformation of one lesion into a squamous cell carcinoma (SCC). Malignancy developing in cutaneous lichen planus is rare, with less than 50 cases reported in the literature. This case highlights the need to be aware of suspicious changes in long-standing HLP to allow early detection of a developing SCC.

Keywords: dermatology; oncology; skin cancer.

Figure 1

Clinical photograph of the hyperkeratotic and verrucous erythematous plaques on the bilateral pretibial regions.

Figure 2

Clinical photograph showing an ulcerated verrucous growth on hypertrophic lichen planus on the anterior side above the right ankle.

Figure 3

Histopathology (x40 magnification) of a punch biopsy from the right shin hyperkeratotic plaque showed irregular epidermal hyperplasia, a subepidermal lymphocytic infiltrate and a proliferation of atypical keratinocytes with nests of atypical keratinocytes infiltrating deep into the dermis, consistent with squamous cell carcinoma.