negativism, mutism and stupor.1 In contrast, pheochromocytoma is a catecholamine-releasing tumor of the sympathetic nervous system that causes hypertension, sweating, and palpitation. 2 Moreover, fever has been commonly observed in patients with pheochromocytoma.3 Thus, although these two disorders have similar manifestations, the similarities between the symptoms of the two conditions have not yet been reported. Here I report a case of MC wherein the manifestations mimicked those of pheochromocytoma. The patient has provided written informed consent for the publication of this letter.A 38-year-old male schizophrenia patient had been treated with antipsychotic drugs. Immediately before admission to Jichi Medical University Hospital, the productivity of his business had declined; consequently, a contract to sell his shop was scheduled to be signed on 23 March. On the evening of 22 March, however, he suddenly became stuporous and was admitted to the emergency department. On admission his systolic blood pressure was 184 mmHg and pulse rate was 120/min. Subsequently, he exhibited alternating stupor and excitement, blood pressure fluctuations, tachycardia, urinary incontinence, profuse diaphoresis, tremor, and increased muscle tone. Although he was afebrile on admission, his body temperature increased to 38.3°C on 29 March. Blood examination indicated a serum creatine phosphokinase level of 1040 IU/L and a white blood cell count of 12 200/mL. The thyroid hormone levels were within the normal range. The C-reactive protein level was not indicative of the presence of an infection. Pheochromocytoma was initially suspected. Twentyfour hour urine sample indicated high levels of adrenaline (24.0 mg/day; normal range: 3-15 mg/day), noradrenaline (312.7 mg/day; normal range, 26-121 mg/day), and vanillylmandelic acid (6.7 mg/day; normal range, 1.4-5.1 mg/day). Abdominal computed tomography (CT) and echography, however, were normal. Hence, the diagnosis of pheochromocytoma was ruled out, and he was diagnosed with MC. Electroconvulsive therapy (ECT) was initiated on 29 March. After the completion of the fourth ECT session, his psychiatric and physical symptoms were resolved.In the case of this patient, pheochromocytoma was ruled out on the basis of imaging. It is sometimes difficult to distinguish MC from pheochromocytoma on biochemistry. Nevertheless, it is suggested that pheochromocytoma is unlikely in most patients showing small increases in the levels of catecholamines and metabolites (<2-3-fold the upper reference limits). The following diagnostic criteria for MC were proposed: acute and severe catatonia along with stupor or excitement, hyperthermia (Ն38.0°C), tachycardia (Ն120 beats/min) or hypertension (Ն150/100 mmHg), and increased muscle tone. The symptoms exhibited by the present patient fulfilled these criteria. These manifestations are also evidenced in cases of neuroleptic malignant syndrome (NMS). MC, however, manifests as psychomotor agitation, stupor, and negativism more frequently.1 Lead-pipe rigidity, a charac...
