Session: MON 37-82-Pheochromocytoma & Paraganglioma
Poster Board MON-66
Newer data suggests that a third or more of apparently sporadic pheochromocytomas have unsuspected genetic mutations. Medullary thyroid carcinoma is commonly associated with pheochromocytoma as part of MEN 2 syndrome. The concomitance of pheochromocytoma and other thyroid diseases, specifically Graves’ or papillary thyroid cancer (PTC), is rare. Persistent symptoms after treatment of Graves' disease require further investigation. To our knowledge, this is the first report of a patient with Graves’ disease, PTC and pheochromocytoma.
A 42-year old female presented to clinic for management of Graves' disease. She was treated with methimazole and subsequently remained biochemically euthyroid for several years. However, symptoms of episodic palpitations, anxiety, and a sensation of “impending doom” persisted. A thyroid ultrasound was performed as part of her evaluation and demonstrated a left upper pole hypoechoic nodule, 0.8 x 0.8 x 1.0 cm, with microcalcifications and mildly increased vascularity. A fine needle aspiration confirmed PTC. Total thyroidectomy with central neck dissection was performed, revealing multifocal PTC. The tumor involved both left and right lobes (largest focus 5.5 mm, left lobe), and two of eight lymph nodes. On postoperative day five, the patient developed fever and tachycardia, and she was evaluated in the emergency room. CT scan of the chest to rule out pulmonary embolism revealed incidental findings of a large soft tissue mass in the right paracaval region and in the hepatic hilar region. MRI of the abdomen confirmed a 4.5 x 2.9 x 4.6 cm mass arising from the medial lobe of the right adrenal gland with heterogenous T2 weighted signal, suspicious for pheochromocytoma. Biochemical evaluation demonstrated elevated plasma and urine normetanephrines [625 pg/mL (0-145 pg/mL) and 5202 mcg/24 h (82-500 mcg/24h), respectively], and the diagnosis of pheochromocytoma was made. Adrenalectomy was performed and pathology confirmed a pheochromocytoma, 4.2 x 4.0 x 2.9 cm, with positive chromogranin immunostain in tumor cells. Genetic testing for RET and VHL was negative.
Several syndromes involving multiple endocrinopathies are well established and have defined genetic mutations. This patient represents a rare case of Graves’ disease, PTC, and pheochromocytoma. Testing for some of the common known genetic mutations causing pheochromocytoma was negative. A novel genetic mutation causing all three disorders cannot be excluded. A plausible mechanism of PTC in this patient may be the effect of circulating catecholamines on TSH secretion. Data also suggests that Graves' disease may be associated with an increased risk of PTC. Persistent adrenergic symptoms after optimal treatment of hyperthyroidism should prompt testing for pheochromocytoma.
Nothing to Disclose: HBL, RK, KMM
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