Melanotic Schwannoma with a High Level of Catecholamine in an Elderly Patient

A 73-year-old woman suffering from hypertension and asthma had chest radiography, which showed the shadow of a lump on the inner side of the right lung apex. From a chest CT scan, it was diagnosed as an upper mediastinal tumor (circular in shape with a diameter of 19×23mm) adjacent to the right rib and showing a low-absorption range. Histopathology confirmed the diagnosis as an Antoni B-type melanotic schwannoma. On suspicion of secondary hypertension, the amount of urinary catecholamine was measured before surgery and this revealed high levels of total catecholamine (184.4μg/day), dopamine (1134.6μg/day) and noradrenaline (169.7μg/day). A normal value of 14.7μg/day of adrenalin was obtained. These measurements were conducted again after surgery, and normal values of 127.8μg/day of total catecholamine, 388.6μg/day of dopamine, 117.9μg/ day of noradrenalin and 9.9μg/day of adrenalin were obtained. In view of these findings, the tumor was thought to be a neurogenic tumor of the sympathetic nervous system and capable of generating melanin. Incidentally, after removal of the tumor, the patient's hypertension became less severe and there was improvement in her asthma attacks.