Malignant Transformation of Dental Material-induced Oral Lichenoid Contact Reaction: A Case Report Describing Outcomes After Amalgam Removal

Oral lichen planus (OLP) is a chronic immune-mediated dermatosis of unknown origin. Considered as one of the most common diseases of the oral mucosa, OLP has been subject of intense interest since its first identification as a premalignant condition. Oral lichenoid contact reactions (OLCRs) are distinct analogs of OLP lesions, in that they are nearly indistinguishable from OLP both clinically and histologically. There is an on-going debate about whether the underlying condition causing OLP-induced malignant oral squamous cell carcinoma is OLP or OLCR. Even currently, a considerable number of patients with OLCR are diagnosed and managed as OLP without searching for specific causative agents. Dental restorative materials are one of the most common inducers of OLCR. Here, we describe a case with dental material-induced OLCR, who had previously undergone marginal mandibulectomy and neck dissection with a diagnosis of invasive well differentiated squamous cell carcinoma associated with OLP. We emphasize the need for investigation of possible etiological factors in every case of OLP or OLCR, as a basal patch test may completely change the course of the disease