Lichen planus is a chronic inflammatory disease that affects the skin and oral mucosa. Although its etiology is unknown , its potential for cancerization has been confirmed by many studies, primarily for lichen involving the oral mucosa . We here report the cases of a brother and sister, both with a 15-year history of nail lichen planus of the fingers and toes, histologically confirmed and treated with topical corticosteroids, who developed squamous cell carcinoma (SCC) of the nail bed and matrix. Informed consent was obtained from each individual participant for inclusion in the study. The present article aims to highlight the importance of a correct diagnosis, treatment, and periodic follow-up of precancerous lesions such as lichen planus (LP) and to explain the underlying mechanisms of neoplastic changes involved in both LP and SCC, probably related to chronic inflammatory processes.
A 60-year-old female was admitted to our hospital for two ulcerated exophytic lesions of 1.5 and 2 cm diameter, respectively, affecting the third and fifth finger of the right hand. The two lesions had arisen 4 years before (Fig. 1). The nails were all affected by lichen planus disease, histologically diagnosed with a 3-mm punch biopsy 15 years before; no other anatomical sites were involved. Dermoscopic features of the exophytic lesions showed the presence of a polymorphic vascular pattern, surrounded by keratinizing whitish areas. Furthermore, two skin biopsy specimens from the two lesions of the fingers were taken. They showed intra-epidermal and infiltrative proliferation of atypical squamous cells with the presence of horn pearls. Moreover, necrotizing aspects were found (Fig. 2). A diagnosis of ulcerating SCC for both lesions was made. The nail bed and matrix were involved, so both fingers were amputated (Fig. 3).
A 55-year-old male presented to our hospital with a 2-cm-diameter ulcerated nodule affecting the left great toe of 4 years' duration. Nails of the other toes and fingers were all affected by lichen planus disease, histologically diagnosed 15 years before. No other lichen planus lesions were observed on the skin, oral muscosa, or genital regions. At dermoscopy, a polymorphic vascular pattern, surrounded by keratinizing whitish areas suggestive of SCC, was present. Furthermore, a 3-mm punch biopsy taken from the nodular lesion of the toe revealed an intra-epidermal and infiltrative proliferation of atypical squamous cells with the presence of squamous cells and horn pearls. Necrotizing cells were also reported. A diagnosis of ulcerating squamous cell carcinoma involving the matrix and nail bed was made. The patient underwent the amputation of the toe (Table 1).