408 would be found in thyrotoxic patients with severe nonthyroidal illness. We believe we have found such a case. In November, 1973, a 63-year-old woman presented with carcinoma of the colon and pelvic metastases. She gave a history of a unilateral thyroid swelling since childhood and she had had an intravenous pyelogram in May, 1973. Clinically she was thyrotoxic. She complained of heat intolerance and excessive She seemed hyperkinetic and the reflexes were nervousness. brisk. Pulse-rate was 96 per minute. There was no significant tremor. Since surgery was regarded as urgent, she was referred to our unit for further evaluation. The thyroid scan appearances were consistent with a " hot " nodule replacing the right lobe with resultant suppression of the left lobe. 10-minute 99MTc Total serum-T4 was uptake was 2-5% (normal