Erosive lichen planus and fibroxanthosarcoma (malignant fibrohistiocytoma): coincidence or association?

Severe erosive lichen planus of the skin and oral and anal mucosae coincided with retroperitoneal fibroxanthosarcoma (malignant fibrohistiocytoma) in an asthmatic patient. Clinical evolution after surgical removal of the tumor, radiotherapy, and chemotherapy was favorable, with great improvement of the lichen planus and the asthma. The exact nature of the relationship between erosive lichen planus and tumors is not known, but there is circumstantial evidence that their coexistence is not just a fortuitous coincidence.