We reviewed the scintigraphic images made after injections of 1-131 metaiodobenzylguanidine (MIBG) or 1-123 MIBG in patients with multiple endocrine neoplasia (MEN) types 2A and 2B. The information we obtained was applied to three questions about the treatment of pheochromocytoma in patients affected with these syndromes. Our first question "When should adrenal gland(s) be removed?" was not directly answered. However, adrenalectomy generally should not be contemplated unless distinct abnormalities are present in the scintigraphic images. With experience it may be possible to approximate, from the stage of pheochromocytoma depicted by scintigraphy, how many years will elapse before symptoms or hypertension will appear in the patient. The second question "Should both adrenal glands always be removed when adrenalectomy is undertaken?" was answered negatively. In some uncommon patients, the development of pheochromocytoma in one adrenal gland may precede by decades the evolution of tumor in the other gland. If an absence of scintigraphic abnormality and a normal appearance and normal response to touch by the surgeon in one adrenal gland are observed, then an appropriate option would be to withhold removal of that gland. Our third question "Can the onset of malignancy be anticipated?" could not be answered by scintigraphic images. However, scintigraphy will reveal metastases already present and thereby will modify the therapeutic approach to the patient. Malignant change is uncommon before tumors exceed 4 cm in diameter. Earlier adrenalectomy may be indicated for members of an MEN kindred in which metastatic pheochromocytoma has already been encountered.
Sisson, James C.; Shapiro, Brahm; and Beierwaltes, William H.
"Scintigraphy with 1-131 MIBG as an Aid to the Treatment of Pheochromocytomas in Patients with the Multiple Endocrine Neoplasia Type 2 Syndromes,"
Henry Ford Hospital Medical Journal
: Vol. 32
Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol32/iss4/12