Breast cancer is known to metastasize to all organs of the human body, and its manifestations are protean. It is almost impossible to predict which organ system will be invaded. Since 1950, there are seven autopsy series of patients with breast carcinoma published in the English literature. All data came from American hospitals (total of 2,147 patients), and each report studied more than 100 patients with breast cancer. The reported incidence of involvement of different organ sites are presented in Table I. Although the data came from different institutions and spanned over 35 years (1943-1977), the findings regarding metastatic involvement of specific organs are fairly similar.