Tylosis with esophageal cancer (TOC) is an inherited condition that increases the risk for esophageal cancer. The symptoms of TOC include thickening of the skin on the palms and soles of the feet (palmoplantar keratoderma) and white lesions inside the mouth. People with TOC are at very high risk to develop esophageal cancer. The palmoplantar keratoderma usually occurs in childhood, and esophageal cancer usually occurs in adulthood. TOC is caused by a variant in the RHBDF2 gene and is inherited in an autosomal dominant pattern. Diagnosis is based on the symptoms, clinical exam, and family history. The diagnosis may be confirmed by the results of genetic testing.