Cowden's disease in three siblings: electron-microscope and immunological studies.

Cowden's disease was diagnosed in three siblings (two sisters and a brother) in a Jewish Israeli family of Yemenite origin. The typical mucocutaneous lesions of the disease were present in all three cases. There were hamartomas involving other body systems, including euthyroid multinodular goiter (in all 3 cases), gastrointestinal polyposis (in 2 cases) and hemangioma (in one case). Developmental anomalies were found in all 3 cases. Histological examination of mucocutaneous lesions was in accordance with previous descriptions, including the findings compatible with trichilemmoma observed in cutaneous facial papules. Extensive electron-microscope studies of these facial lesions yielded no evidence of viral particles. Immunological studies, carried out mainly in two cases, revealed a decrease in complement level in the serum and impairment of T cell function.