Abstract
Muir-Torre syndrome (MTS) is an autosomal dominantly inherited disease caused by a pathological germ-line mutation in one of the mismatch repair genes and is considered a phenotypic variant of Lynch syndrome. Our patient was a 61-year-old man. He had had colorectal cancer at the ages of 36, 38, 46 and 56, respectively, and gastric cancer at the age of 50. Two people among his second-degree relatives had colorectal cancer. He met Amsterdam Criteria II, and we suspected the case to be Lynch syndrome and followed it up. He had a 10 mm nodule on his back at age 61. It was a sebaceous carcinoma. He previously had internal malignancies, therefore, we diagnosed the case as MTS. Gene analysis revealed germ-line mutation in the MLH1 gene, and we diagnosed the case as Lynch syndrome. Gastroenterological surgeons should be concerned about MTS when a patient with Lynch syndrome has a sebaceous tumor.
