[Cowden syndrome].

A patient with multiple hamartoma syndrome or Cowden's disease with multiple gastrointestinal polyps and malignant melanoma is presented. The syndrome is characterized by hamartomatous tumors of the skin, fibrocystic disease of the breasts, gastrointestinal polyps and disease of the thyroid gland such as goiter and adenoma. In addition, other abnormalities and malformations occur in the skeletal system, central nervous system and urogenital tract. Recognition of this syndrome is important because of the association with malignant tumors of the breast and thyroid gland and with malignant melanoma. Gastrointestinal hamartomatous polyps may lead to the diagnosis of Cowden's disease which must be separated from other intestinal polyposis syndromes.