Endocrine Abstracts

Introduction: Pheochromocytoma occurs in 50% of patients with multiple endocrine neoplasia syndrome type 2A (MEN2A). It is characterized by bilateral location, production of large amounts of adrenalin and a benign course, extraadrenal location being rare. Diagnosis is achieved by measuring catecholamines and metanephrines in serum or urine and/or through imaging techniques, including CT, MRI and 123I-MIBG scintigraphy.

Objective: To describe clinical features of pheocromocytomas found in a MEN2A family.

Subjects and methods: Descriptive observational study. Eight MEN2A patients belonging to the same family who carry C634Y mutation at proto-oncogene RET.

Results: Three out of eight subjects developed pheochromocytomas. All of them of bilateral location. Case 1 (index) was diagnosed because of typical spells after the surgery of a thyroid nodule that proved to be a medullary thyroid cancer (MTC). CT evidenced bilateral adrenal masses. Case 2 (case 1’s son) was diagnosed in a familial study through a MRI which showed an image suggestive of pheochromocytoma on the right adrenal gland, although metanephrines levels were normal. Five years later, another mass appeared at the left adrenal gland, suggestive of adenoma and with a non-conclusive 123-MIBG image. Epinephrine and metanephrine rose slightly although they did not reach a diagnostic value. Adrenalectomy was performed and anatomic pathology confirmed the diagnosis. Case 3 (case 1’s daughter) was also diagnosed in a familial study. MRI evidenced a left adrenal nodule suggestive of adenoma but having a high uptake at 123I-MIBG. Adrenalectomy was executed and anatomic pathology confirmed diagnosis. Three years later MRI showed a right adrenal nodule suggestive of pheochromocytoma. Catecholamines and metanephrines were always moving among the normal limits.

Conclusion: In our family with MEN2A by C634Y mutation, pheochromocytoma showed peculiarities such as absence of catecholamines hyperproduction and bilateral but asynchronous presentation. It requires a continuous and combined follow-up with imaging and laboratory techniques.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.