Cowden's disease. A case report with analyses at the molecular level.

Cowden's disease (multiple hamartoma syndrome) is characterized by multiple hamartomas of ectodermal, endodermal, and mesodermal origin, a high incidence of malignant tumors of the breast and/or thyroid gland, and an autosomal dominant pattern of inheritance. Similar to sporadic breast cancer, chromosomal studies have not elucidated the cause of this syndrome. The authors report the case of a patient with this syndrome and analyze the pattern of amplification or rearrangement of three genes: the HER-2/neu oncogene, the ras oncogene, and the estrogen-inducible gene, pS-2. All three of these genes were present in single copies without translocations. It was noteworthy that three of the most important genes currently studied in relation to breast cancer existed in a unamplified unrearranged state in this patient. Those with clinical manifestations of Cowden's disease may be candidates for prophylactic bilateral total mastectomy, and the authors recommend that these patients undergo this procedure by their third decade of life. An alternative to this approach would entail monthly self examinations, breast examinations by the patient's physician every 3 months, bilateral mammograms every 6 to 12 months, and biopsy of any suspicious lesions. It is crucial, however, that these patients be identified by their mucocutaneous lesions and family history before an underlying malignant lesion develops.