LAUSR

EJD, vol. 28, n◦ 3, May-June 2018 secondary lesions. Treatment consisted of left transtibial amputation. The presented cases are the first reported cases of bilateral SCC arising from cutaneous ulcerative LP of extremities. Less than 70 cases of SCC in conjunction with cutaneous LP have been reported. No case of bilateral SCC has so far been reported. In the majority of cases, LP was of hypertrophic type and localised to the lower limb [-7]. No palmar sites are described in the literature. The erosive type was reported in only four cases [2-5], but they all concerned the lower limb [2-5], including two affecting the sole [3, 4]. In our two cases, both patients did not develop SCC in other parts of their body, in particular, photo-exposed areas. They reported no history of arsenic exposure, ultraviolet radiation, burn scars, or chronic tar application [8]. Chronic inflammation increases cellular turnover, inflow of growth factors, and free radical formation, furthering the occurrence of malignancy. However, no significant association has been found between cutaneous LP and SCC [2]. An erosive form is generally associated with poor treatment response [9] and a long-standing non-healing ulceration [8, 10]. Risk increases with ulcer duration [10]. Furthermore, lesions that recur at the same sites on the extremities are an obstacle to treatment. Finally, since both patients were at risk of malignant transformation, they underwent systemic immunosuppressive therapy and phototherapy, respectively [8]. In summary, we have identified three factors that could render LP malignant: the erosive type, localisation at the extremities, and exposure to potentially carcinogenic agents in immunosuppressive treatments. Chronic inflammation, long-standing and non-healing ulceration, and chronic exposure to some carcinogenic agents promote malignancy. For cases of cutaneous ulcerative lichen planus of the extremities, we recommend thorough monitoring.