Probable pheochomocytoma
Urinary catecholamines and catecholamine metabolites are all elevated. Plasma norepinephrine
is markedly elevated, but epinephrine is within the normal range. Be aware that catecholamine
secretion by pheochromocytomas is episodic, and different results might be obtained from a
sample drawn half an hour later. The urinary free catecholamines are probably the best test
for pheochromocytoma because they essentially measure output over time. Note that more tests were done than were
really needed for diagnosis in this case--the urinary free catecholamines alone would have
been sufficient.
Clinical course
A CT scan of the adrenals revealed an 8 cm mass on the left side. The patient was treated with
alpha and beta blockers (catecholamine receptor blocking agents) for several weeks and had
no further paroxysms during that time. His blood pressure declined to 110/78. He then
underwent abdominal surgery with removal of 250 g pheochromocytoma.
Notes
It is important to make this diagnosis for several reasons. This is a curable form of hypertension
in relatively young people. If the tumor is removed and the hypertension is terminated before too
long, they can be spared the vascular disease that accompanies long-term hypertension. Furthermore,
pheochromocytomas may metastasize after a period of time (about 10% do). Early recognition and
removal can be curative of the tumor as well as the hypertension.
In this patient, the elevated epinephrine in the urine indicated that the tumor
was located in the adrenal medulla. Similar tumors may be located outside the adrenal gland. When
they are, they are called extra-adrenal paragangliomas rather than pheochromocytomas, and they
produce norepinephrine but not epinephrine.
