Abstract
Cowden disease is a rare autosomal dominant inherited disorder with variable expression including characteristic mucocutaneous lesions and hamartomatous neoplasms of the whole body. It is well known that the disease is associated with malignant neoplasms in a high incidence in patients past middle age. Recently we have experienced a case of Cowden disease in a postmastectomy patient for breast cancer in whom we found and resected an associated thymic tumor and adenomatous goiter. The patient was a 46-year-old woman. At the age of 23 years when she was treated for diabetes mellitus, she was identified to have multiple small papules on the face and keratotic papules in the body. In addition she had been associated with intestinal polyps and papilloma of the tongue and the pharynx since earlier. Cowden disease was diagnosed based on findings of resected specimen of a nasal papule and a gene analysis at the age of 38. Mastectomy was performed for left breast cancer at the age of 45, when a cystic tumor at the anterior mediastinum and a right pulmonary nodular shadow were disclosed by a chest CT scan. FDG-PET revealed slightly abnormal uptake of fluorodeoxyglucose in the anterior mediastinum. Thymoma was suspected and total thymectomy + total thyroidectomy + partial pneumonectomy were simultaneously performed. The histopathological diagnosis was multiple thymic cysts, adenomatous goiter, and pulmonary hamartoma. The patient's postoperative course was uneventful and she has been followed in our clinic.
