Endocrine Abstracts

Introduction: Metoclopramide is known to exert stimulatory effects on catecholamine secretion, having been used in the past as provocative test in the diagnosis of pheochromocytoma. We describe a patient with an incidentally discovered pheochromocytoma after metoclopramide administration.

Case report: A 64 years-old woman underwent total thyroidectomy for multinodular goiter with ‘follicular proliferation Thy 3’ at FNAB of the target nodule. The patient was affected by mild not paroxysmal hypertension adequately treated with doxazosine 2 mg/day. About 12 h after surgery she has postoperative nausea treated with 10 mg i.v. metoclopramide. After few minutes she developed a severe hypertensive crisis non-responsive to i.v. furosemide and i.m. clonidine but responsive to 10 mg i.v. phentolamine. Blood samples showed a severe hyperglycemia (>700 mg/dl). The patient was transferred in intensive care unit for pulmonary edema and acute respiratory distress. Hypertensive crisis and hyperglycemia arisen after the administration of metoclopramide were strongly suggestive for pheochromocytoma. The diagnosis was confirmed by urinary catecholamines and metanephrines which resulted exceptionally high (epinephrines 95.8 mcg/day [n.v. 2–22]; norepinephrines 154.3 mcg/day [n.v. 12–86]; metanephrine 4424 mcg/day [n.v. 50–340]; normetanephrine 4288 mcg/day [n.v. 90–445]) while abdominal CT scan showed a 66 mm right adrenal mass. Therefore, patient underwent right adrenalectomy after one week treatment with doxazosine by nasogastric tube and i.v. phentolamine. Adrenal histology confirmed pheochromocytoma, while thyroid histology showed a papillary microcarcinoma. The patient was carefully followed after adrenal surgery by copious hydration: blood pressure normalized in absence of anti-hypertensive drugs. Urinary catecholamines and metanephrines normalized.

Conclusion: The incidentally diagnosis of pheochromocytoma after an hypertensive crisis induces by metoclopramide has been described in Literature. Thus, it is crucial to consider this possibility in presence of a severe hypertensive crisis after the administration of this drug particularly in the post-operative course.

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.