The case of a 65 old woman who had a rapidly progressive neurologic symptomatology is reported. The autopsy disclosed a carcinoma of the breast with metastases in brain, cerebellum, brainstem, pituitary, tyreoid gland and the adrenals. The frequency of the pituitary metastases is discussed, especially in cases of breast cancer. The macro and microscopic aspects of the metastatic pituitary gland are studied.