Abstract
<title>Abstract</title> <p> <bold>Background</bold> : Giant ectopic pheochromocytoma is a rare clinical entity and is typically characterized by hypertension and other catecholamine-related symptoms. Although diabetes mellitus is relatively common among patients with pheochromocytoma, severe adhesion between the tumor and adjacent organs, possibly associated with diabetes-related chronic inflammation, is rarely reported. <bold>Case presentation</bold> : A 78-year-old woman with diabetes mellitus was admitted to hospital because of abdominal pain. Plasma metanephrine(15.91 pg/mL) and normetanephrine(63.87 pg/mL) levels were within the normal ranges, respectively. Imaging examinations revealed a giant para-aortic mass with an indistinct boundary between the tumor and a segment of the colon. Intraoperatively, severe adhesion was observed between the tumor and the local sigmoid colon as well as the left ureter. With multidisciplinary surgical management, the operation was successfully completed. Postoperative pathological examination confirmed the diagnosis of pheochromocytoma. <bold>Conclusion</bold> : This report describes a rare case of giant ectopic pheochromocytoma occurring in a patient with poorly controlled diabetes mellitus and accompanied by severe adhesion to adjacent organs. Diabetes mellitus may promote peritumoral adhesion through chronic inflammatory mechanisms. For such patients, comprehensive preoperative assessment, multidisciplinary surgical collaboration, and perioperative glycemic control are essential for reducing surgical risk. </p>