Multiple squamous cell carcinoma developed at sites of chronic lichen planus of the skin of a Negro man. In addition, the patient's course was complicated by permanent, partial anhidrosis. The onset of similar lesions in an offspring makes this a most unusual case of lichen planus.
Kronenberg K, Fretzin D, Potter B. Malignant Degeneration of Lichen Planus. Arch Dermatol. 1971;104(3):304-307. doi:10.1001/archderm.1971.04000210078015