The opportunity to observe the effect of administration of pituitary adrenocorticotrophic hormone (ACTH) and 11-dehydro-17-hydroxycorticosterone (cortisone) on the moderately active rheumatoid arthritis of a patient with panhypopituitarism was presented us. The clinical features (1, 2) of hypopituitarism are in essence those of hypo-function of the so-called "target" organs of the pituitary; the adrenal cortex, thyroid, and gonads. Sheehan and Summers (1) report "rheumatism of joints particularly of the knees" in 13 of 93 cases of panhypopituitarism, but elucidate no further on this clinical feature. The physiologic effects of ACTH and cortisone are well knonn (3,4), and the dramatic response of patients with rheumatoid arthritis to these agents has been amply recorded (3,5,6 would become apparent after ACTH administration.3. The response to cortisone.Case Report: LER, a 46 year old white woman, was first seen in the out-patient clinic at University Hospitals in 1945, complaining of intermittent attacks of swelling and tenderness of the shoulders, wrists, fingers, knees, and ankles. Recent attacks were associated with fever, anorexia, and weight loss. A vague history of increased heat tolerance was obtained. The husband described episodes that suggested hypoglycemia which had occurred intermittently during the preceding seven years. Menstrual and obstetrical history revealed that the only pregnancy, 27 years previously, had terminated with a prolonged labor, associated with excessive blood loss. Lactation was minimal, and ceased entirely after seven days. Menstrual function was not present after the pregnancy. Examination showed an asthenic, poorly nourished woman with dry skin. There was diminution of axillary and pubic hair. Blood presEure was 100/70 mm. Hg. Minimal joint signs were evident. Basal metabolic rates were -22%o and -27%. Erythrocyte sedimentation rate was 86 mm./hour (Westergren). Clinical diagnoses of hypothyroidism and rheumatoid arthritis were made. The patient was discharged on thyroid substance 0.1 gm. daily.There were four subsequent clinic visits, the final one being in August, 1946. Thyroid substance had been used only sporadically. On each occasion the patient complained of tachycardia. Little clhange was observed in the general appearance. The erythrocyte sedimentation rate remained elevated. On one occasion, a typical rheumatoid lesion of a metacarpal-phalyngeal joint was noted.She was admitted to the medical service in January, 1949. During the previous 30 months she had experienced progressive asthenia and increasing periods of sleep. Her only medication had been 30 mg. of thyroid substance daily. In recent months progressive swelling and tenderness in the right knee and left ankle had been observed. Examination showed a very torpid and listless woman whose weight was 106 pounds. The skin had no increased pigmentation and was smooth and dry. Axillary and pubic hair were sparse. The breasts were atrophic. The heart was small. Blood pressure was 70/50. Pelvic examination revealed an atr...