Giant cystic malignant pheochromocytoma invading right hepatic lobe: report on two cases.

Context: Cystic pheochromocytomas are uncommon neuroendocrine tumors that originate from the adrenal medulla. Differing from the more frequent solid pheochromocytomas, which produce catecholamines and present adrenergic syndrome, cystic pheochromocytomas may not produce these. Their symptoms are generally associated with an abdominal mass or even pain, particularly if the mass attains large dimensions.