Keratitis, ichthyosis and deafness syndrome with development of multiple hair follicle tumours

Abstract
We report multiple occurrences of various kinds of tumours that originate from hair follicles in a patient diagnosed with KID (keratitis, ichthyosis, deafness) syndrome. These tumours are diagnosed as: (i) trichilemmal cysts in early lesions; (ii) proliferating trichilemmal tumours in moderate duration lesions; and (iii) malignant proliferating trichilemmal tumours in advanced lesions that are thought to progress from benign trichilemmal lesions. This three-step process raises the hypothesis of a multihit model that could account for the frequent development of tumours in KID patients.