-About 17% of adrenal cases are bilateral (suggesting hereditary disease)
-About 18.4% of adrenal cases occur in children (also suggesting hereditary disease)
-About 15% are extra-adrenal (located in any orthosympathetic tissue): of these 9% are in the abdomen and 1% are located elsewhere. Some extra-adrenal phaeochromocytomas are probably actually paragangliomas, but the distinction is only possible after surgical resection.
-About 11.1% of adrenal cases are malignant, but this rises to 30% for extra-adrenal cases
-About 26% are hereditary (earlier opinion had 10%)
-About 3% recur after being resected
-About 14% of affected individuals do not have arterial hypertension