Cowden syndrome is a rare cancer predisposition syndrome inherited in an autosomal-dominant fashion. The syndrome is characterized by hamartomatous polyps that affect multiple organs: skin, mucous membranes, thyroid, breast, gastrointestinal tract, endometrium and brain. It is also associated with an increased risk of developing malignancy in many tissues but especially breast, thyroid and endometrium. Thyroid tumor is ranging from benign nodule to frank malignancy. We report a case of WDT UMP in 66 years old lady who has CS.