Ambulatory Blood Pressure Monitoring in Diagnosing a Pheochromocytoma of the Urinary Bladder

A patient is presented in whom the preoperative diagnosis of an intravesical pheochro mocytoma was facilitated by noninvasive ambulatory blood pressure monitoring. A fifty- two-year-old Japanese man suffered headache and palpitation after micturition. Cystoscopy revealed an intravesical tumor. To investigate whether his symptoms were associated with an elevation of blood pressure, the authors monitored his ambulatory blood pressure automatically for twenty-four hours. The patient was also instructed to activate the recording manually upon the onset of symptoms. As a result, elevations of blood pressure were apparent following micturition. The twenty-four-hour urinary excretion of norepinephrine was elevated on the day of the blood pressure monitoring. Pheochromocytoma was suspected and was confirmed by histopathologic studies following the operation. Thus, ambulatory blood pressure monitoring may be useful in detecting the transient hypertension induced by micturition, which can provide preop erative evidence of pheochromocytoma of the urinary bladder.