A 23 yr - daisy187

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A 23-year-old man known to have neurofibromatosis, type 1 (von Recklinghausen's disease),
presents with a left lower quadrant abdominal mass and signs of neurologic deficits in his left
leg. In the ensuing workup, it is determined that he has higher than normal values of
catabolites of epinephrine and norepinephrine in a 24-hour urinary collection. He is currently
normotensive. Before invasive steps are taken to biopsy and eventually remove his left lower
quadrant abdominal mass, which of the following is the most appropriate next step in
management?
A. CT scan of the head looking for meningiomas
B. MRI of his adrenal glands
C. MRI of the acoustic nerves
D. Radionuclide scans from the neck to the pelvis looking for extra-adrenal
pheochromocytomas
E. Radiation therapy to the left lower quadrant abdominal mass
The

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BB

[ArchivalUser]

d?

[ArchivalUser]

The correct answer is B. The concern is that even though he is now normotensive,
invasive steps might trigger a hypertensive crisis from the previously undiagnosed
pheochromocytoma that he probably has. The presence of catabolites from epinephrine
indicates that the tumor is in the adrenal glands, and not at an extra-adrenal site. Thus,
the diagnosis of the pheochromocytoma can best be confirmed by MRI of the adrenals.
Meningiomas (choice A) and acoustic nerve tumors (choice C) occur in type 2
neurofibromatosis, not in type 1.
Looking for pheochromocytomas outside of the adrenal glands (choice D) would have
been a good idea if only elevated catabolites of norepinephrine had been detected. The
presence of high levels of epinephrine catabolites implicates the adrenal glands.
Radiation therapy (choice E) is a bad idea. Benign neurofibromas can be stimulated by
radiation to undergo malignant transformation.