A review of 371 cases of malignant tumors coming to autopsy at the State Institute for the Study of Malignant Disease revealed 49 cases in which the adrenal gland showed metastatic involvement. Two cases of primary adrenal tumors, one a medullary type tumor in a three-year-old boy, the other arising in the cortex of the right adrenal of a female of advanced years, are also found in this series. I. Metastatic Tumors Malignant epithelial tumors of the breast, esophagus, stomach, testicle and penis, as well as Hodgkin's disease and the malignant melanomas, seem to show a special tendency to metastasize to the adrenals. The dissemination of tumor tissue may be either through the lymphatic system or by way of the blood stream. While as a general rule the regional lymph nodes are first involved, many lesions metastasize to distant organs and do not involve the intervening nodes. In many cases of advanced cancer the thoracic duct is invaded, resulting in a widespread dissemination of the tumor. The blood vessels usually offer the chief channels for dissemination of the sarcomas.