[Low dose CVD chemotherapy as a tumor dormancy therapy for extra-adrenal malignant pheochromocytoma: a case report].

A 38 year-old man presented with upper abdominal mass and hypertension pointed out at a medical examination. Blood pressure was 170/90 under medication of an alpha-blocker. Abdominal CT scan showed an 8 x 8 cm inter-aortocaval mass displacing pancreas head ventrally, and further a 4 x 4 cm mass at the aortic bifurcation, but there was no tumorous lesion in bilateral adrenal glands. Plasma nor-epinephrine level and urinary VMA excretion were excessive but plasma adrenaline level was within normal limits. MIBG scintigram showed hot spots in the 4th and 9th thoracic vertebrae. The destructive change of the 9th vertebra on magnetic resonance imaging strongly suggested metastasis of the tumor. Histologic and immunohistochemical findings of the biopsy specimen taken from the lower abdominal tumor in addition to the above clinical data led to the diagnosis of extra-adrenal malignant pheochromocytoma with spinal metastases. Since 2 cycles of full dose CYVADIC chemotherapy had no effects on lowering the high blood pressure and reducing the tumor size, low dose (60% of the full dose) CVD (cyclophosphamide, vincristine and dacarbazine) was given as a palliative chemotherapy on an out-patient clinic approximately every 4 weeks. After 4 cycles of the chemotherapy, his backache due to spinal metastasis markedly improved, hypertension as well as the plasma dopamine level was normalized and nor-epinephrine level was markedly decreased, though the tumor size was not reduced. Thereafter, no medication for hypertension was necessary. During 3 years and 6 months until now, 36 cycles of the chemotherapy has been repeated with no significant side effects. He has been at full-time work with quality of life being well preserved. Low dose CVD regimen appears to be an effective tumor dormancy therapy for advanced extra-adrenal pheochromocytoma.