PS-BPR01-8: A CASE OF PHEOCHROMOCYTOMA WITH CONCOMITANT SPLENIC ARTERY ANEURYSM

Abstract

A 62-year-old man with a 30-year history of headaches and a 20-year history of treatment-resistant hypertension and diabetes mellitus was referred to our hospital for evaluation of his 5 cm retroperitoneal tumor found by abdominal ultrasound examination at a medical checkup. A simple CT and MRI scan showed a heterogeneous tumor (diameter, 5 cm) in the left adrenal gland and a splenic artery aneurysm (diameter, 2 cm). Endocrine examinations revealed increased levels of plasma-free normetanephrine (NMN) (853 pg/mL), urinary noradrenaline (NA) (670 μg/day), and urinary NMN (2.6 mg/day). 123I-MIBG scintigraphy showed high accumulation in the left adrenal region. He was diagnosed with NA-dominant left pheochromocytoma. His blood pressure was controlled at around 140/90 mmHg with 16 mg of doxazosin and 10 mg of amlodipine. His insulin-dependent diabetes was treated with multiple daily insulin injections (63 units/day), metformin, and miglitol. First, he underwent splenic artery aneurysm embolization under general anesthesia, which was completed without developing a hypertensive crisis. Two months later, he underwent laparoscopic left adrenalectomy, and the resected tumor was pathologically diagnosed as pheochromocytoma with a GAPP score of 1. He did not develop postoperative hypotension. His blood pressure was well controlled with only 10 mg of amlodipine, and his insulin requirement was reduced to 23 units/day after surgery. Since few cases of pheochromocytoma with concomitant splenic artery aneurysm have been reported, we discussed the treatment plan with much consideration. Splenic artery aneurysms have a high risk of rupture due to intraoperative blood pressure elevation in pheochromocytoma, which could be fatal. Although the first choice of treatment for a splenic artery aneurysm is endovascular therapy, the use of contrast media is generally contraindicated in pheochromocytoma in Japan due to the risk of hypertensive crisis. In the present case, systemic management with a sufficiently high dose of alpha-blocker allowed the embolization to be preceded avoiding a crisis, and subsequent surgery for pheochromocytoma could be performed safely. A long history of hypertension and diabetes exacerbated by the pheochromocytoma may have contributed to the arteriosclerosis leading to the splenic artery aneurysm. Here we report a rare case of pheochromocytoma with concomitant splenic artery aneurysm and will discuss the pathogenesis and management of this case with a review of the literature.