ABSTRACT
Tylosis with esophageal cancer (TOC) is a rare, autosomal dominant disorder characterized by tylotic changes (focal thickening of the skin, callus formation, or hyperkeratosis) of the palms and soles (so-called palmoplantar keratoderma [PPK]), oral leukokeratosis, and a high lifetime risk (95% at the age of 65) of esophageal squamous cell carcinoma. While PPK usually begins around age 10, esophageal cancer occurs after age 20. At the molecular level, TOC is linked to missense mutations in the rhomboid 5 homolog 2 (RHBDF2) gene located on chromosome 17q25.1 [1].
