Elevated Calcitonin Levels in a Patient With a Pheochromocytoma: A Case Report

Elevated calcitonin and catecholamine levels in patients with adrenal masses and thyroid nodules are suspicious for multiple endocrine neoplasia type 2A. Here, we present an interesting case with elevated catecholamines, thyroid nodules, and hypercalcitoninemia. A 46-year-old woman with complaint of abdominal pain was recently hospitalized. Abdominal computed tomography elicited a 7 cm left adrenal mass. Upon presentation to our clinic, the patient complained of abdominal pain, nausea, and diaphoresis. Laboratory studies showed elevated catecholamines, and a pheochromocytoma was subsequently diagnosed. Further evaluation elicited elevated calcitonin levels and a suspicious 3 cm left thyroid nodule, inciting concern for medullary thyroid carcinoma. The patient underwent an uneventful robot-assisted laparoscopic left adrenalectomy. Surgical pathology confirmed a pheochromocytoma. Post-operative calcitonin levels resolved to within normal range. The patient elected to undergo a left hemithyroidectomy. Surgical pathology confirmed calcitonin-negative nodular hyperplasia, negative for malignancy. The patient's diagnosis was confined to a pheochromocytoma. Clinicians should investigate high calcitonin levels associated with a pheochromocytoma as it may not always be ascribed to the thyroid.